• Re: Collatz Conjecture proved.

    From wij@3:633/10 to All on Sunday, January 25, 2026 00:37:38
    On Wed, 2025-12-24 at 20:05 +0800, wij wrote:


    I have just finished the script. Any defect,insufficiency, or typo?

    ------------------
    This file is intended a proof of Collatz Conjecture. The contents may be updated anytime. https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/do wnload

    The text is converted by google translate with modest modification from https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-zh.txt/do wnload
    Reader might want to try different translator or different settings.

    ---------------------------------------------------------------------------
    --
    Collatz function ::=

    int cop(int n) {
    if(n<=1) {
    if(n<1) {
    throw Error;
    }
    return 1; // 1 is the iteration endpoint
    }
    if(n%2) {
    return 3*n+1; // Odd number rule
    } else {
    return n/2; // Even number rule
    }
    }

    Collatz number: If an integer n, n?N<1,+1>, after the cop iteration
    will
    eventually calculate to 1 (i.e., cop(...cop(n))=1), then n is a Colla
    tz
    number. Otherwise n is not a Collatz number.

    Collatz Problem: For each integer n, n?N<1,+1>, is n a Collatz numb
    er? IOW,
    the question is equivalent to asking whether the following procedure rc
    op
    terminates or not.

    void rcop(int n) {
    for(;n!=1;) {
    n=cop(n);
    }
    }

    Prop: cop(n) iteration contains no cycle (except for the '1-4-2-1' cycle, s ince
    1 is the termination condition).
    Proof: n can be decomposed into n= a+b. rcop(n) can be rewritten as rco p2(n):

    void rcop2(int n) {
    int a=n,b=0;
    for(;a+b!=1;) { // a+b= n in the cop iterative process.
    if((a%2)!=0) {
    --a; ++b; // Adjust a and b so that a remains even and the
    // following algorithm can be performed and remains

    // equivalent to cop(n) iteration.
    }
    if((b%2)!=0) { // Equivalent to (a+b)%2 (because a is even).
    a= 3*a;
    b= 3*b+1; // 3*(a+b)+1= (3*a) +(3*b+1)
    } else {
    a= a/2;
    b= b/2;
    }
    }
    }

    Let n?, a?, b? represent the values n,a, and
    b in the iteration.
    Assume that the cop(n) iteration is cyclic. The cycle is a fixed-leng
    th
    sequence, and the process must contain the operations 3x+1 and x/2 (a
    nd
    the associated operations --a and ++b, unless n is a 2^x number, but such
    numbers do not cycle). Let the cyclic sequence of n be:
    n?, n?, n?, ..., n? (n=n?
    ).
    Because --a and ++b are continuously interpolated during the cycle, i
    f
    a??0, then b? and n?=a?+b
    ? will increase infinitely, contradicting the
    assumption that n? is cyclic. Therefore, a?=0 must
    hold during the cycle,
    but the condition of a?=0 only exists in 1-4-2-1, a?
    ?=0 cannot cause the
    non-1-4-2-1 cycle of n?,n?,n?,...,n?.
    Therefore, we can conclude that cop(n) iterations are non-cyclic.

    Prop: For any n?N<1,+1>, the cop iteration operation terminates.
    Proof: Since an odd number n will always become even immediately after th
    e
    cop iteration, it must undergo n/2 iterations. Therefore, we have an
    equivalent rcop3:

    void rcop3(int n) {
    int a=n,b=0;
    for(; a+b!=1;) {
    if((a%2)!=0) {
    --a; ++b;
    }
    // a/b measure point A
    if((b%2)!=0) {
    a= 3*a;
    b= 3*b+1;
    }
    a= a/2;
    b= b/2;
    }
    }

    Let n be odd and there be no `--a`, `++b` process. Assume that each o
    dd
    operation is paired with only one even operation (the actual ratio is
    1.5
    even operations, but 1.5 is a statistical value; the decisive inferen
    ce
    can only take the guaranteed value of 1). Then, at measurement point
    A,
    we have:

    a? = n-1
    a? = (3*a???)/2 = ... = (n-1)*(
    3/2)???
    b? = 1
    b? = (3*b???+1)/2 = ... = 2*(3/
    2)??? -1
    a?/b? = (a???)/(b?
    ??) = ((n-1)*(3/2)???)/(2*(3/2)?
    ?? -1)
    = ... = (n-1)/(2-1/(3/2)???)

    Interim summary: a?/b? < a???
    /b??? and lim{x->ì} a?/b?
    = (n-1)/2.
    (After eight iterations, a?/b? is approximately 0.5
    1. Actual iterations
    may also include --a and ++b operations, so the actual value of a
    ?/b?
    will converge faster than the formula)

    Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    => b = (a+b)/(r+1)
    Assuming the cop(n) iteration does not terminate, and m is one of the
    number in the iteration sequence. Therefore, we can derive the
    following:
    => b = m/(r+1)
    => The limit of r+1 = (m-1)/2 + 1 = (m+1)/2
    => b = (2*m)/(m+1) = 2/(1+1/m)
    => b = 2 (the limit of b. At least it is known that m will be a l
    arge
    number)

    Since there is a limit (the numerical value is not important), the
    iteration involves an infinite number of iterations of --a, a will
    inevitably become zero, so the iteration cannot fail to meet the
    iteration termination contion.

    If n is even, then repeating the even operation (a finite number of t imes)
    cop(n) will yield an odd number without affecting the termination res
    ult
    as stated above. Therefore, the proposition is proved.

    [Reference] Real number and infinity. Recurring decimals are irrational num bers.
    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en .txt/download


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Lawrence D?Oliveiro@3:633/10 to All on Sunday, January 25, 2026 00:23:41
    On Sun, 25 Jan 2026 00:37:38 +0800, wij wrote:

    [Reference] Real number and infinity. Recurring decimals are
    irrational numbers.

    No they are not. ?Irrational? means ?not expressible as a ratio?. The
    ?ratio? in question means that of two integers. Recurring decimals are
    always expressible as a ratio of two integers, and the proof of this
    is pretty trivial.

    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From James Kuyper@3:633/10 to All on Saturday, January 24, 2026 23:06:05
    On Sun, 25 Jan 2026 00:37:38 +0800, wij wrote:

    [Reference] Real number and infinity. Recurring decimals are
    irrational numbers.

    So x = 0.1212.... is irrational?
    100x = 12.1212...
    - x = -0.1212...
    === ==========
    99x = 12
    x = 4/33

    This generalizes to work with any recurring decimal. When the recurrence
    is n digits long (in the above example, n=2), just multiply by 10^n.

    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Sunday, January 25, 2026 13:28:31
    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:
    On Sun, 25 Jan 2026 00:37:38 +0800, wij wrote:

    [Reference] Real number and infinity. Recurring decimals are
    irrational numbers.

    So x = 0.1212.... is irrational?
    100x = 12.1212...
    -ÿ x = -0.1212...
    ÿ===ÿÿ ==========
    ÿ99x = 12
    x = 4/33

    This generalizes to work with any recurring decimal. When the recurrence
    is n digits long (in the above example, n=2), just multiply by 10^n.

    Such arithmetic is called approximation, or magic proof simply because
    no such axiom/theorem exists (it will cause contradiction).

    Take Prop2 for example: "0.1212..." should mean 12/100 +12/10000 +12/100000
    0 +....
    Infinite addition of rational numbers cannot be rational number the same re ason
    as infinite addition of natural numbers cannot be a natural number.
    Bunches of reasons are there.

    ----------------- https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/d ownload
    .....[cut]

    Prop 1: The statement ?+?=? (or, let a,b?
    ? (natural numbers), then a+b??) holds
    only for a finite number of addition steps.
    Proof: Non-zero natural numbers are strictly increasing when added togeth
    er.
    Adding with an infinite number of steps will yield a number of
    infinite length. By Axiom 1, such a number is not a natural number
    .

    Prop 2: ?+?=? (the sum of a rational number and a
    rational number is still a
    rational number) The statement holds only for a finite number of
    addition steps.
    Proof: If the positive rational number q is strictly increasing by
    accumulation, and the infinite term q = a/b = q?+q?
    ??+q?..., then either
    a or b must be infinitely large.

    The above propositions raise a question:
    a+b = (a+b) ... leads to the dubious conclusion a,b?N => a+b
    ?N (or the
    question of the number of applications requires explanat ion).
    a/b+c/d = (ad+cb)/bd ... leads to the dubious conclusion a,b?
    ? => a+b?? (not
    always true).
    Thus, formal logic cannot handle propositions involving the concept of
    infinite procedures.

    Prop 3: Recurring decimals are irrational numbers.
    Proof: Let x be a recurring decimal, 0<x<1, x has a recurring period S, a
    nd is
    written in the base system as x=0.S?S?S?...S?
    ??. Then by definition x= S?/b
    +S?/bý +S?/b? +... +Sì/b^ì =
    q? +q? +q? +...+qì (b??).
    That is, recurring decimals are a special case of "?+?".
    According to Prop 2,
    when adding terms infinitely, x is not a rational number (i.e., irrationa
    l).

    Note: By the way, a brief explanation of common algebraic magic:
    (1) x= 0.999...
    (2{ 10x= 9.999... // may implicitly define 0.999... in (1)
    (3) 10x= 9+x
    (4) 9x=9
    (5) x=1
    Answer: There is no axiom or theorem to prove that (1) <=> (3).
    (3) is one of the infinite interpretations of (1), or (3) is the
    'introduction' definition of 0.999..., etc. In short, there is no
    necessary relationship between (3) and (1), or it still needs to be
    proved. For example, 0.999... formed by 1/2+1/4+1/8+... does not hav
    e the
    property of (3).

    There are actually many other examples, for example:
    1. If 0.999... = 1 holds, then it can be proved that the unique
    prime
    factorization theorem of positive integers does not hold:
    0.999... = 999.../1000... = 9*(111...)/(5*2)*... =1
    <=> 3*3*(111...) = (5*2)*...
    The integer to the left of the equal sign contains the prime nu mber
    3, but the integer to the right cannot contain 3... Prime
    factorization is not unique.
    2. Are the intervals [0,1) and [0,1] equal? 0.999...?[0,1)
    ? What number
    is to the left of 1 (infinitely close)? Can we define a number
    x
    that can be infinitely close to c but not equal to c (e.g.,
    0.999...*c)?...
    3. 1/3 = 0.333... + non-zero-remainder (True identity. How to de
    ny?)
    .... [cut]
    ------------------



    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Lawrence D?Oliveiro@3:633/10 to All on Sunday, January 25, 2026 08:15:02
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the
    recurrence is n digits long (in the above example, n=2), just
    multiply by 10^n.

    Such arithmetic is called approximation ...

    No, it?s exact.

    I think your problem is you are trying to think about maths using a
    specific low-level programming language (C or C++) which only supports finite-precision integers.

    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Sunday, January 25, 2026 16:46:43
    On Sun, 2026-01-25 at 08:15 +0000, Lawrence D?Oliveiro wrote:
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the
    recurrence is n digits long (in the above example, n=2), just
    multiply by 10^n.

    Such arithmetic is called approximation ...

    No, it?s exact.

    Prove it. No one wants blind belief.

    I think your problem is you are trying to think about maths using a
    specific low-level programming language (C or C++) which only supports finite-precision integers.

    Your problem is just repeating what you are told to repeat, no meaning.


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Sunday, January 25, 2026 10:38:48
    On 25/01/2026 09:46, wij wrote:
    On Sun, 2026-01-25 at 08:15 +0000, Lawrence D?Oliveiro wrote:
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the
    recurrence is n digits long (in the above example, n=2), just
    multiply by 10^n.

    Such arithmetic is called approximation ...

    No, it?s exact.

    Prove it. No one wants blind belief.

    I think your problem is you are trying to think about maths using a
    specific low-level programming language (C or C++) which only supports
    finite-precision integers.

    Your problem is just repeating what you are told to repeat, no meaning.



    It's a long time since I did proofs of the properties and arithmetic of rational numbers, but I certainly did them at university. I also
    derived the real numbers from Peano axioms. It is not "blind belief",
    it is easily within the capabilities of maths undergraduates. I am not
    going to go through such a derivation of rational numbers and decimal expansions here - if you don't accept the simple, clear proof given by
    James, a long one working directly from the ZF axioms is going to be far
    over your head, and a lot of effort for no gain. I am confident,
    however, that both James and Lawrence could also do such proofs themselves.

    What you seem to be doing is inventing your own "axioms" (without any justification, or proof of either consistency or necessity), inventing
    your own definitions for well-established mathematical objects (like the rational numbers) without any proofs, derivations, or explanations, and
    then making wild claims that aren't even justified within your own system.

    It's a complete mess, and there is little point in anyone trying to pull
    it apart to help correct your errors. As the meme goes, it's not even
    wrong. You have a lot of work ahead of you to "unlearn" the
    misconceptions that drive you here, before you can begin to learn some mathematics.

    And it is totally off-topic for C and C++. The last thing these groups
    need is another Olcott. You also post sometimes on C and C++ - please
    stick to those topics in this group.




    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Sunday, January 25, 2026 18:55:15
    On Sun, 2026-01-25 at 10:38 +0100, David Brown wrote:
    On 25/01/2026 09:46, wij wrote:
    On Sun, 2026-01-25 at 08:15 +0000, Lawrence D?Oliveiro wrote:
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the recurrence is n digits long (in the above example, n=2), just multiply by 10^n.

    Such arithmetic is called approximation ...

    No, it?s exact.

    Prove it. No one wants blind belief.

    I think your problem is you are trying to think about maths using a specific low-level programming language (C or C++) which only support
    s
    finite-precision integers.

    Your problem is just repeating what you are told to repeat, no meaning.



    It's a long time since I did proofs of the properties and arithmetic of

    rational numbers, but I certainly did them at university.ÿ I also

    derived the real numbers from Peano axioms.ÿ It is not "blind belief
    ",
    it is easily within the capabilities of maths undergraduates.ÿ I am
    not
    going to go through such a derivation of rational numbers and decimal expansions here - if you don't accept the simple, clear proof given by

    James, a long one working directly from the ZF axioms is going to be far

    over your head, and a lot of effort for no gain.ÿ I am confident,

    however, that both James and Lawrence could also do such proofs themselve
    s.

    What you seem to be doing is inventing your own "axioms" (without any justification, or proof of either consistency or necessity), inventing

    your own definitions for well-established mathematical objects (like the

    rational numbers) without any proofs, derivations, or explanations, and

    then making wild claims that aren't even justified within your own system
    .

    It's a complete mess, and there is little point in anyone trying to pull

    it apart to help correct your errors.ÿ As the meme goes, it's not ev
    en
    wrong.ÿ You have a lot of work ahead of you to "unlearn" the
    misconceptions that drive you here, before you can begin to learn some

    mathematics.

    And it is totally off-topic for C and C++.ÿ The last thing these gro
    ups
    need is another Olcott.ÿ You also post sometimes on C and C++ - plea
    se
    stick to those topics in this group.




    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Sunday, January 25, 2026 19:06:40
    On Sun, 2026-01-25 at 10:38 +0100, David Brown wrote:
    On 25/01/2026 09:46, wij wrote:
    On Sun, 2026-01-25 at 08:15 +0000, Lawrence D?Oliveiro wrote:
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the recurrence is n digits long (in the above example, n=2), just multiply by 10^n.

    Such arithmetic is called approximation ...

    No, it?s exact.

    Prove it. No one wants blind belief.

    I think your problem is you are trying to think about maths using a specific low-level programming language (C or C++) which only support
    s
    finite-precision integers.

    Your problem is just repeating what you are told to repeat, no meaning.



    It's a long time since I did proofs of the properties and arithmetic of

    rational numbers, but I certainly did them at university.ÿ I also

    derived the real numbers from Peano axioms.ÿ It is not "blind belief
    ",
    it is easily within the capabilities of maths undergraduates.ÿ I am
    not
    going to go through such a derivation of rational numbers and decimal expansions here - if you don't accept the simple, clear proof given by

    James, a long one working directly from the ZF axioms is going to be far

    over your head, and a lot of effort for no gain.ÿ I am confident,

    however, that both James and Lawrence could also do such proofs themselve
    s.

    I see no proof, just opinion, 'blind belief', repeating. I was expecting
    more like copy-paste.... Just cannot prove anything yourself.

    What you seem to be doing is inventing your own "axioms" (without any justification, or proof of either consistency or necessity), inventing

    your own definitions for well-established mathematical objects (like the

    rational numbers) without any proofs, derivations, or explanations, and

    then making wild claims that aren't even justified within your own system
    .

    It's a complete mess, and there is little point in anyone trying to pull

    it apart to help correct your errors.ÿ As the meme goes, it's not ev
    en
    wrong.ÿ You have a lot of work ahead of you to "unlearn" the
    misconceptions that drive you here, before you can begin to learn some

    mathematics.

    Said a lot, but I am afraid soon you will find you are accusing yourself.
    That is embarrassing, but I know people will forget, and at most findÿ
    excuse for themselves.

    And it is totally off-topic for C and C++.ÿ The last thing these gro
    ups
    need is another Olcott.ÿ You also post sometimes on C and C++ - plea
    se
    stick to those topics in this group.

    I agree such repeating decimal is rational or not things may be off-topic,
    ÿ
    but who brought it up?
    Please stick to the topic. There are many C/C++ stuff in my post, why you people always choose to pick non-topic to post???ÿ
    You know the truth in subconscious?


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Sunday, January 25, 2026 12:47:59
    On 25/01/2026 12:06, wij wrote:
    On Sun, 2026-01-25 at 10:38 +0100, David Brown wrote:
    On 25/01/2026 09:46, wij wrote:

    And it is totally off-topic for C and C++.ÿ The last thing these groups
    need is another Olcott.ÿ You also post sometimes on C and C++ - please
    stick to those topics in this group.

    I agree such repeating decimal is rational or not things may be off-topic, but who brought it up?

    /You/ brought it up - in your references for your off-topic post. I
    can't say why James picked that particular part to focus on - perhaps it
    is because it was clear what you had written, and obviously totally
    false and a complete misunderstanding of rational numbers, limits, and
    decimal representations, as well as demonstrating that you don't
    understand how mathematics works. It is much harder to criticise the
    Collatz Conjecture stuff, because what you have written is gobbledegook.
    Perhaps it made some sense in your original language (I may be wrong,
    but I think it is Chinese), but has been mangled beyond recognition by
    machine translation.

    Please stick to the topic. There are many C/C++ stuff in my post, why you people always choose to pick non-topic to post???
    You know the truth in subconscious?


    The Collatz conjecture is totally off-topic here. Writing a function
    for it in C does not make it on-topic.

    Now, if you want to talk purely about a C implementation of the Collatz function, perhaps looking at ways to handle it efficiently for large
    numbers, that might be an interesting and on-topic here.

    If you really had proof of the Collatz conjecture, especially one this
    short, it would be sensational - Abel prize or Fields medal level stuff.
    We should be hearing about it in the mainstream news. It is an
    example of a problem that is easy to explain, but extraordinarily
    difficult to proof. You should be talking about it in mathematics
    arenas, not a C newsgroup - and I strongly recommend you do so in a
    group in your native language.


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Sunday, January 25, 2026 23:44:13
    On Sun, 2026-01-25 at 12:47 +0100, David Brown wrote:
    On 25/01/2026 12:06, wij wrote:
    On Sun, 2026-01-25 at 10:38 +0100, David Brown wrote:
    On 25/01/2026 09:46, wij wrote:

    And it is totally off-topic for C and C++.ÿ The last thing these
    groups
    need is another Olcott.ÿ You also post sometimes on C and C++ -
    please
    stick to those topics in this group.

    I agree such repeating decimal is rational or not things may be off-top
    ic,
    but who brought it up?

    /You/ brought it up - in your references for your off-topic post.ÿ I

    can't say why James picked that particular part to focus on - perhaps it

    is because it was clear what you had written, and obviously totally
    false and a complete misunderstanding of rational numbers, limits, and

    decimal representations, as well as demonstrating that you don't
    understand how mathematics works.ÿ It is much harder to criticise th
    e
    Collatz Conjecture stuff, because what you have written is gobbledegook.

    ÿ Perhaps it made some sense in your original language (I may be wro
    ng,
    but I think it is Chinese), but has been mangled beyond recognition by

    machine translation.

    Please stick to the topic. There are many C/C++ stuff in my post, why y
    ou
    people always choose to pick non-topic to post???
    You know the truth in subconscious?


    The Collatz conjecture is totally off-topic here.ÿ Writing a functio
    n
    for it in C does not make it on-topic.

    Do posters have to write a C function for sales of tissue paper to beÿ on-topic? It is because you believe you know C (but shallow).

    Now, if you want to talk purely about a C implementation of the Collatz

    function, perhaps looking at ways to handle it efficiently for large numbers, that might be an interesting and on-topic here.

    Why did I often heard you guys arguing about wild 'philosophy' of Cÿ
    language (hardly C related) all day long. You are not the king.

    If you really had proof of the Collatz conjecture, especially one this

    short, it would be sensational - Abel prize or Fields medal level stuff.

    ÿ We should be hearing about it in the mainstream news.ÿ It is
    an
    example of a problem that is easy to explain, but extraordinarily
    difficult to proof.ÿ You should be talking about it in mathematics

    arenas, not a C newsgroup - and I strongly recommend you do so in a
    group in your native language.

    Sounds to confirm what I thought: All is simply because you are not there
    but 'believe' you are. You like to mimic the TV-professional style excuse.

    You cannot evaluate the simple proof of Collatz problem (even in short C/C+
    +).ÿ
    But choose to wait to be told to believe and think you understand.
    The same as "N+N=N infinitely is false", you cannot see it yourself but w
    ait
    to be told, and think you understand the basic.


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From James Kuyper@3:633/10 to All on Sunday, January 25, 2026 11:25:34
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the
    recurrence is n digits long (in the above example, n=2), just
    multiply by 10^n.

    Such arithmetic is called approximation ...

    So what is, in your opinion, the exact representation of 4/33 as a
    decimal fraction? Marking it as infinitely repeating means that it is
    not in any sense an approximation - it is exact. If it were an
    approximation, there would be a finite difference between 4/33 and
    0.1212.... How big is that difference? No matter how small of a finite difference you might think it has, going to infinitely many decimal
    digits makes the actual difference smaller than that.
    Keep in mind that, in the absence of specification to the contrary,
    we're talking about the standard real number system, not one of those alternatives that extends the real number system by adding
    infinitesimals, such as the surreals or the hyperreals.

    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Monday, January 26, 2026 01:20:28
    On Sun, 2026-01-25 at 11:25 -0500, James Kuyper wrote:
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the
    recurrence is n digits long (in the above example, n=2), just
    multiply by 10^n.

    Such arithmetic is called approximation ...

    So what is, in your opinion, the exact representation of 4/33 as a
    decimal fraction? Marking it as infinitely repeating means that it is
    not in any sense an approximation - it is exact.

    You need to prove 4/33 exactly equal to 0.1212..., not approximation.
    But,...

    If it were an
    approximation, there would be a finite difference between 4/33 and
    0.1212.... How big is that difference? No matter how small of a finite difference you might think it has, going to infinitely many decimal
    digits makes the actual difference smaller than that.

    Yes, the same as infinity/infinitesimal.

    Keep in mind that, in the absence of specification to the contrary,
    we're talking about the standard real number system, not one of those alternatives that extends the real number system by adding
    infinitesimals, such as the surreals or the hyperreals.

    Trueÿif you are not referring to the current 'standard real number sys
    tem'.
    What else? (doesn't sound to contain much information)

    The standard real number system is not a constant thing, it will correct itself. Not even religion is constant.

    To be explicitly 'C' related, I remember people talking about what INF?
    ?
    should mean (an option may be merely for signifying overflow), I would
    suggest reserve the bit, not mixing with other meaning.


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From James Kuyper@3:633/10 to All on Sunday, January 25, 2026 12:22:17
    On 2026-01-25 06:47, David Brown wrote:
    On 25/01/2026 12:06, wij wrote:
    ...
    I agree such repeating decimal is rational or not things may be
    off-topic,
    but who brought it up?

    /You/ brought it up - in your references for your off-topic post. I
    can't say why James picked that particular part to focus on - perhaps
    it is because it was clear what you had written, and obviously totally
    false and a complete misunderstanding of rational numbers, limits, and decimal representations, as well as demonstrating that you don't
    understand how mathematics works.

    I've got wij filtered out, so I didn't see his original post. I did see Laurence's response, which contained only the part I responded to. But
    what you're saying is why I decided to respond to it.
    My killfile is not intended as a punishment, nor as a promise that I
    will ignore all messages posted by someone, it's just meant to reduce my annoyance by protecting me from having to pay even minimal attention to
    the people in the list. When it fails, I sometimes feel a desire to respond.
    In Thunderbird, I was able to take Laurence's response, select "Edit as
    New Message", delete Laurence's text, and create a new message that had
    headers marking it as a direct response to wij's post, not Laurence's.


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Lawrence D?Oliveiro@3:633/10 to All on Sunday, January 25, 2026 18:52:29
    On Sun, 25 Jan 2026 16:46:43 +0800, wij wrote:

    On Sun, 2026-01-25 at 08:15 +0000, Lawrence D?Oliveiro wrote:

    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the
    recurrence is n digits long (in the above example, n=2), just
    multiply by 10^n.

    Such arithmetic is called approximation ...

    No, it?s exact.

    Prove it. No one wants blind belief.

    Sure. Consider the general case of a fractional number X which can be represented by a repeating decimal:

    X = 0.a?a?...a?b?b?...b?b?b?...b?...

    where the a?s and b?s are decimal digits, such that a?a?...a?
    represents the initial non-repeating part, consisting of m digits,
    where m ò 0, and b?b?...b? represents the repeating part, consisting
    of n digits, where n > 0. First, separate out the non-repeating part:

    X * 10 ** m = a?a?...a?.b?b?...b?b?b?...b?...

    from which

    X * 10 ** m - a?a?...a? = 0.b?b?...b?b?b?...b?...
    = (b?b?...b? ö 10 ** n) + (b?b?...b? ö 10 ** ný) + ...
    = (b?b?...b? ö (10 ** n - 1))

    Notice that?s a closed-form expression: no more indefinitely-repeating
    parts at all. The right-hand side is a ratio of two integers, which is
    what makes it ?rational?. If it?s not already in its lowest terms, it
    can be made so, by cancelling out common factors. Since there are only
    a finite number of integers between those values and 1, those lowest
    terms exist somewhere along the point between the two, and can always
    be found in a finite number of steps. QED.

    I think your problem is you are trying to think about maths using a
    specific low-level programming language (C or C++) which only
    supports finite-precision integers.

    Your problem is just repeating what you are told to repeat, no
    meaning.

    You?re not familiar with languages that support infinite-precision
    integers, are you?

    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Monday, January 26, 2026 03:58:25
    On Sun, 2026-01-25 at 18:52 +0000, Lawrence D?Oliveiro wrote:
    On Sun, 25 Jan 2026 16:46:43 +0800, wij wrote:

    On Sun, 2026-01-25 at 08:15 +0000, Lawrence D?Oliveiro wrote:

    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the recurrence is n digits long (in the above example, n=2), just multiply by 10^n.

    Such arithmetic is called approximation ...

    No, it?s exact.

    Prove it. No one wants blind belief.

    Sure. Consider the general case of a fractional number X which can be represented by a repeating decimal:

    ÿÿÿ X = 0.a?a?...a?b?b
    ?...b?b?b?...b?...

    where the a?s and b?s are decimal digits, such that a?
    ??a?...a?
    represents the initial non-repeating part, consisting of m digits,
    where m ò 0, and b?b?...b? represents the
    repeating part, consisting
    of n digits, where n > 0. First, separate out the non-repeating part:

    ÿÿÿ X * 10 ** m = a?a?...a?.b?
    ??b?...b?b?b?...b?...

    from which

    ÿÿÿ X * 10 ** m - a?a?...a? = 0.
    b?b?...b?b?b?...b?...
    ÿÿÿÿÿÿÿ = (b?b?...b
    ? ö 10 ** n) + (b?b?...b? ö 10 **
    ný) + ...
    ÿÿÿÿÿÿÿ = (b?b?...b
    ? ö (10 ** n - 1))

    Notice that?s a closed-form expression: no more indefinitely-repe
    ating
    parts at all. The right-hand side is a ratio of two integers, which is
    what makes it ?rational?. If it?s not already in
    its lowest terms, it
    can be made so, by cancelling out common factors. Since there are only
    a finite number of integers between those values and 1, those lowest
    terms exist somewhere along the point between the two, and can always
    be found in a finite number of steps. QED.

    Not different from the popular 0.999...=1 magic, but 'rewrote' in more ug
    ly
    form (I just thought real experts like simple proof, semi-experts like to complicated proof and believe it, even though they don't really understand it!).

    X * 10 ** m - a?a?...a? = 0.b?b?
    ?...b?b?b?...b?...
    = (b?b?...b? ö 10 ** n) + (b?
    ?b?...b? ö 10 ** ný) + ...
    = (b?b?...b? ö (10 ** n - 1)) // wh
    at rule makes this valid derivation
    // from the above line?

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/d ownload
    ...[cut]
    (1) x= 0.999...
    (2{ 10x= 9.999... // may have implicitly defined 0.999... is 1
    (3) 10x= 9+x
    (4) 9x=9
    (5) x=1
    Answer: There is no axiom or theorem to prove that (1) <=> (3).
    (3) is one of the infinite interpretations of (1), or (3) is the
    'introduction' definition of 0.999..., etc. In short, there is no
    necessary relationship between (3) and (1), or it still needs to be
    proved. For example, 0.999... formed by 1/2+1/4+1/8+... does not hav
    e the
    property of (3).
    ----------
    You might be using infinite series, see the link.

    Anyway, whatever the specific proof is, you still need to refute the proof

    shown in the previous post, Prop1,Prop2,Prop3. You cannot pretending blind
    to
    escape it.

    I think your problem is you are trying to think about maths using a specific low-level programming language (C or C++) which only
    supports finite-precision integers.

    Your problem is just repeating what you are told to repeat, no
    meaning.

    You?re not familiar with languages that support infinite-precisio
    n
    integers, are you?

    No, I don't believe 'infinite-precision integer' is representable.
    See the link.


    --- PyGate Linux v1.5.5
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Janis Papanagnou@3:633/10 to All on Monday, January 26, 2026 01:25:28
    (I probably regret answering to your post.)

    On 2026-01-25 18:20, wij wrote:

    You need to prove 4/33 exactly equal to 0.1212..., not approximation.

    Is that all you want proven; a specific example?

    This appears to be as trivial as the more general approach that James
    gave and that you (for reasons beyond me) don't accept (or don't see).

    First
    __
    0.12 or 0.1212...

    are just finite representations of real numbers; conventions. And 4/33
    is an expression representing an operation, the division. You can just
    do that computation (as you've certainly learned at school decades ago)
    in individual steps, continuing each step with the remainder

    4/33 = 0 => 0
    40/33 = 1 => 0.1
    remainder 7
    70/33 = 2 => 0.12
    remainder 4
    40/33 = 1 and at this point you see that the _operations_ *repeat*

    so the calculated decimals (1 and 2) will also repeat. And sensibly we
    need a finite representation (see above) to express that.

    Albert Einstein (for example) said: ?Die Definition von Wahnsinn ist,
    immer wieder das Gleiche zu tun und andere Ergebnisse zu erwarten?.

    Are you expecting the sequence of decimals differing at some point?

    If not you see that the number represented by the convention "0.1212..."
    equals to the number calculated or expressed by "4/33".

    Janis


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Monday, January 26, 2026 23:51:55
    On Mon, 2026-01-26 at 01:25 +0100, Janis Papanagnou wrote:
    (I probably regret answering to your post.)

    On 2026-01-25 18:20, wij wrote:

    You need to prove 4/33 exactly equal to 0.1212..., not approximation.

    Is that all you want proven; a specific example?

    This appears to be as trivial as the more general approach that James
    gave and that you (for reasons beyond me) don't accept (or don't see).

    First
    ÿÿÿÿ __
    ÿÿ 0.12ÿÿ orÿÿ 0.1212...

    are just finite representations of real numbers; conventions. And 4/33
    is an expression representing an operation, the division. You can just
    do that computation (as you've certainly learned at school decades ago)
    in individual steps, continuing each step with the remainder

    ÿÿ 4/33 = 0ÿÿÿÿ => 0
    ÿÿ 40/33 = 1ÿÿÿ => 0.1
    ÿÿ remainder 7
    ÿÿ 70/33 = 2ÿÿÿ => 0.12
    ÿÿ remainder 4
    ÿÿ 40/33 = 1ÿÿÿ and at this point you see that
    the _operations_ *repeat*

    so the calculated decimals (1 and 2) will also repeat. And sensibly we
    need a finite representation (see above) to express that.

    ÿÿ Albert Einstein (for example) said: ?Die Definition
    von Wahnsinn ist,
    ÿÿ immer wieder das Gleiche zu tun und andere Ergebnisse zu erw
    arten?.

    Are you expecting the sequence of decimals differing at some point?

    If not you see that the number represented by the convention "0.1212..." equals to the number calculated or expressed by "4/33".

    Janis
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/d ownload
    3. 1/3 = 0.333... + non-zero-remainder (True identity. How to de
    ny?)

    How would you deny it, and call the cut-off 'equation' identity?
    You cut off non-zero-remainder to stop repeating, so yes, you see the part
    you
    want to see, i.e. the front part without "...", and forgot the definition "infinitely repeat" is invalidated.
    Let n(i) be the repeating number 0.999... The range [n(i),1] remains 1-1 correspondence to [0,1] in each step, nothing changed except scale. Or you suggests every zooming of the small area of Mandelbrot set will be 'empty'
    or
    uniform or 'stop' for some mysterious reason.

    I assume you disagee my point in the previous post that every denial must refute Prop 1= Repeating N+N infinitely does not yield natural number.
    Prop 2= Repeating Q+Q infinitely does not yield rational number.
    (precisely, positive rational number)


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Tuesday, January 27, 2026 00:07:02
    On Mon, 2026-01-26 at 23:51 +0800, wij wrote:


    The proof is pretty much finalized, only 122 lines.
    rcop3(int n) is provided with guidelines about how to prove it. But no one
    can
    verify, because it is told and so believed IMPOSSIBLE! Funny! 15 lines of c odes
    with verification instructions, no one can test, and think they are expert
    C
    developer!
    Posting is just a procedure and must assume some can verify (don't make the mistake, the self-illusion that I need your 'professional' verification).

    https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/do wnload
    ....[cut]
    void rcop3(int n) {
    int a=n,b=0;
    for(; a+b!=1;) {
    if((a%2)!=0) {
    --a; ++b;
    }
    // a/b measure point A
    if((b%2)!=0) {
    a= 3*a;
    b= 3*b+1;
    }
    a= a/2;
    b= b/2;
    }
    }

    // .....
    This proof demonstrates:
    1. The ratio a/b is decreasing.
    2. b has limit.
    3. a must decrease to below b because of the above reasons.
    4. Done, n=a+b has limit (cop(n) is known to terminate for n<2?
    ?? at
    least.
    ---------------------------------

    Funny!!!!!!!!


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Monday, January 26, 2026 21:05:55
    On 26/01/2026 17:07, wij wrote:
    On Mon, 2026-01-26 at 23:51 +0800, wij wrote:


    The proof is pretty much finalized, only 122 lines.
    rcop3(int n) is provided with guidelines about how to prove it. But no one can
    verify, because it is told and so believed IMPOSSIBLE! Funny! 15 lines of codes
    with verification instructions, no one can test, and think they are expert C developer!
    Posting is just a procedure and must assume some can verify (don't make the mistake, the self-illusion that I need your 'professional' verification).

    https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/download
    ....[cut]
    void rcop3(int n) {
    int a=n,b=0;
    for(; a+b!=1;) {
    if((a%2)!=0) {
    --a; ++b;
    }
    // a/b measure point A
    if((b%2)!=0) {
    a= 3*a;
    b= 3*b+1;
    }
    a= a/2;
    b= b/2;
    }
    }

    // .....
    This proof demonstrates:

    You haven't given any kind of a proof. You have given an algorithm,
    written in a silly way (C is not appropriate for mathematical proofs).
    Without the explanations, justifications, and logical steps forming a
    coherent argument, there is no proof.

    But let's take your code as it is. It is correct that given a positive
    "n", and ignoring the range limitation of "int" (that's one reason why C
    is a silly way to write such things), then the algorithm will stop if
    and only if successive applications of the Collatz function result in 1.

    1. The ratio a/b is decreasing.

    That is almost correct. At the start of the algorithm, a/b is n/0,
    which we can view here as positive infinity. For each run through the algorithm, a/b either decreases, or stays the same. So the ratio is non-increasing, rather than strictly decreasing. But any sequence of
    repeated runs without a decrease will be finite in length, so it will
    always decrease after enough runs.

    2. b has limit.

    I see no justification for that claim. (And you don't mention whether
    that limit is dependent on n, or some absolute limit.)

    3. a must decrease to below b because of the above reasons.

    I see no justification for that claim. Even if you are correct that b
    has a limit (it may be true, even though you have done nothing to show
    it), that would not justify this claim.

    If b first exceeds a, then it will stay greater than a, but there is no
    proof that that is guaranteed to happen.

    4. Done, n=a+b has limit (cop(n) is known to terminate for n<2?? at
    least.

    We know it will terminate for n < 2 ** 71, because that has been tested experimentally.


    Funny!!!!!!!!


    Hilarious.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Monday, January 26, 2026 21:07:13
    On 26/01/2026 16:51, wij wrote:
    On Mon, 2026-01-26 at 01:25 +0100, Janis Papanagnou wrote:
    (I probably regret answering to your post.)

    On 2026-01-25 18:20, wij wrote:

    You need to prove 4/33 exactly equal to 0.1212..., not approximation.

    Is that all you want proven; a specific example?

    This appears to be as trivial as the more general approach that James
    gave and that you (for reasons beyond me) don't accept (or don't see).

    First
    ÿÿÿÿ __
    ÿÿ 0.12ÿÿ orÿÿ 0.1212...

    are just finite representations of real numbers; conventions. And 4/33
    is an expression representing an operation, the division. You can just
    do that computation (as you've certainly learned at school decades ago)
    in individual steps, continuing each step with the remainder

    ÿÿ 4/33 = 0ÿÿÿÿ => 0
    ÿÿ 40/33 = 1ÿÿÿ => 0.1
    ÿÿ remainder 7
    ÿÿ 70/33 = 2ÿÿÿ => 0.12
    ÿÿ remainder 4
    ÿÿ 40/33 = 1ÿÿÿ and at this point you see that the _operations_ *repeat*

    so the calculated decimals (1 and 2) will also repeat. And sensibly we
    need a finite representation (see above) to express that.

    ÿÿ Albert Einstein (for example) said: ?Die Definition von Wahnsinn ist,
    ÿÿ immer wieder das Gleiche zu tun und andere Ergebnisse zu erwarten?.

    Are you expecting the sequence of decimals differing at some point?

    If not you see that the number represented by the convention "0.1212..."
    equals to the number calculated or expressed by "4/33".

    Janis
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/download
    3. 1/3 = 0.333... + non-zero-remainder (True identity. How to deny?)

    How would you deny it, and call the cut-off 'equation' identity?

    Have you ever heard of the concept of "limits" ? You might want to
    learn something about them before embarrassing yourself.

    You cut off non-zero-remainder to stop repeating, so yes, you see the part you
    want to see, i.e. the front part without "...", and forgot the definition "infinitely repeat" is invalidated.
    Let n(i) be the repeating number 0.999... The range [n(i),1] remains 1-1 correspondence to [0,1] in each step, nothing changed except scale. Or you suggests every zooming of the small area of Mandelbrot set will be 'empty' or uniform or 'stop' for some mysterious reason.

    I assume you disagee my point in the previous post that every denial must refute Prop 1= Repeating N+N infinitely does not yield natural number.
    Prop 2= Repeating Q+Q infinitely does not yield rational number.
    (precisely, positive rational number)



    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Tuesday, January 27, 2026 04:34:33
    On Mon, 2026-01-26 at 21:07 +0100, David Brown wrote:
    On 26/01/2026 16:51, wij wrote:
    On Mon, 2026-01-26 at 01:25 +0100, Janis Papanagnou wrote:
    (I probably regret answering to your post.)

    On 2026-01-25 18:20, wij wrote:

    You need to prove 4/33 exactly equal to 0.1212..., not approximatio
    n.

    Is that all you want proven; a specific example?

    This appears to be as trivial as the more general approach that James gave and that you (for reasons beyond me) don't accept (or don't see)
    .

    First
    ÿÿÿÿÿ __
    ÿÿÿ 0.12ÿÿ orÿÿ 0.1212...

    are just finite representations of real numbers; conventions. And 4/3
    3
    is an expression representing an operation, the division. You can jus
    t
    do that computation (as you've certainly learned at school decades ag
    o)
    in individual steps, continuing each step with the remainder

    ÿÿÿ 4/33 = 0ÿÿÿÿ => 0
    ÿÿÿ 40/33 = 1ÿÿÿ => 0.1
    ÿÿÿ remainder 7
    ÿÿÿ 70/33 = 2ÿÿÿ => 0.12
    ÿÿÿ remainder 4
    ÿÿÿ 40/33 = 1ÿÿÿ and at this point yo
    u see that the _operations_ *repeat*

    so the calculated decimals (1 and 2) will also repeat. And sensibly w
    e
    need a finite representation (see above) to express that.

    ÿÿÿ Albert Einstein (for example) said: ?Die D
    efinition von Wahnsinn ist,
    ÿÿÿ immer wieder das Gleiche zu tun und andere Ergebni
    sse zu erwarten?.

    Are you expecting the sequence of decimals differing at some point?

    If not you see that the number represented by the convention "0.1212.
    .."
    equals to the number calculated or expressed by "4/33".

    Janis
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.t
    xt/download
    ÿÿÿÿÿÿÿÿÿ 3. 1/3 = 0.333
    ... + non-zero-remainder (True identity. How to deny?)

    How would you deny it, and call the cut-off 'equation' identity?

    Have you ever heard of the concept of "limits" ?ÿ You might want to

    learn something about them before embarrassing yourself.

    What do you know about the concept of "limits"? (You invented? Don't try to
    be
    the next one, again. I remember the other expert in this forum has humiliat
    ed himself
    once, not sure which one, if I can safely predict. And I ignored the other reply,
    because it is tooÿobvious, I leave as record)

    You cut off non-zero-remainder to stop repeating, so yes, you see the p
    art you
    want to see, i.e. the front part without "...", and forgot the definiti
    on
    "infinitely repeat" is invalidated.
    Let n(i) be the repeating number 0.999... The range [n(i),1] remains 1-
    1
    correspondence to [0,1] in each step, nothing changed except scale. Or
    you
    suggests every zooming of the small area of Mandelbrot set will be 'emp
    ty' or
    uniform or 'stop' for some mysterious reason.

    I assume you disagee my point in the previous post that every denial mu
    st
    refute Prop 1= Repeating N+N infinitely does not yield natural number
    .
    ÿÿÿÿÿÿÿ Prop 2= Repeating Q+Q infi
    nitely does not yield rational number.
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ?ÿÿÿ (precisely, positive rational number)



    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Tuesday, January 27, 2026 09:21:51
    On 26/01/2026 21:34, wij wrote:
    On Mon, 2026-01-26 at 21:07 +0100, David Brown wrote:
    On 26/01/2026 16:51, wij wrote:
    On Mon, 2026-01-26 at 01:25 +0100, Janis Papanagnou wrote:
    (I probably regret answering to your post.)

    On 2026-01-25 18:20, wij wrote:

    You need to prove 4/33 exactly equal to 0.1212..., not approximation. >>>>
    Is that all you want proven; a specific example?

    This appears to be as trivial as the more general approach that James
    gave and that you (for reasons beyond me) don't accept (or don't see). >>>>
    First
    ÿÿÿÿÿ __
    ÿÿÿ 0.12ÿÿ orÿÿ 0.1212...

    are just finite representations of real numbers; conventions. And 4/33 >>>> is an expression representing an operation, the division. You can just >>>> do that computation (as you've certainly learned at school decades ago) >>>> in individual steps, continuing each step with the remainder

    ÿÿÿ 4/33 = 0ÿÿÿÿ => 0
    ÿÿÿ 40/33 = 1ÿÿÿ => 0.1
    ÿÿÿ remainder 7
    ÿÿÿ 70/33 = 2ÿÿÿ => 0.12
    ÿÿÿ remainder 4
    ÿÿÿ 40/33 = 1ÿÿÿ and at this point you see that the _operations_ *repeat* >>>>
    so the calculated decimals (1 and 2) will also repeat. And sensibly we >>>> need a finite representation (see above) to express that.

    ÿÿÿ Albert Einstein (for example) said: ?Die Definition von Wahnsinn ist, >>>> ÿÿÿ immer wieder das Gleiche zu tun und andere Ergebnisse zu erwarten?. >>>>
    Are you expecting the sequence of decimals differing at some point?

    If not you see that the number represented by the convention "0.1212..." >>>> equals to the number calculated or expressed by "4/33".

    Janis
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/download
    ÿÿÿÿÿÿÿÿÿ 3. 1/3 = 0.333... + non-zero-remainder (True identity. How to deny?)

    How would you deny it, and call the cut-off 'equation' identity?

    Have you ever heard of the concept of "limits" ?ÿ You might want to
    learn something about them before embarrassing yourself.

    What do you know about the concept of "limits"? (You invented? Don't try to be
    the next one, again. I remember the other expert in this forum has humiliated himself
    once, not sure which one, if I can safely predict. And I ignored the other reply,
    because it is tooÿobvious, I leave as record)


    No, I did not invent the concept of limits. Newton and Leibnitz were
    probably the first to use them, then Cauchy formalized them (if I
    remember my history correctly). But I /learned/ about them - understood
    them, understood proofs about them, understood how to use them.

    And more importantly, I learned how mathematics works. I learned how to
    read proofs, and how to write proofs. So I know writing down some
    statement and claiming "True identity. How to deny?" does not
    constitute a proof.

    But I suspect any rational argument will fall on deaf ears here. You
    don't understand mathematics, and instead think that you alone have
    reinvented it and every other mathematician current and historical was
    wrong. I would love to be able to help you and cure your delusions, but
    I have no idea how to do that. So I will just have to do as others
    have, and ignore you.




    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Janis Papanagnou@3:633/10 to All on Tuesday, January 27, 2026 18:24:58
    On 2026-01-27 17:31, Waldek Hebisch wrote:

    Actually, part that is needed here is ancient, due to Eudoksos. Namely,
    real numebers a and b are equal if and only if comparing them with
    rational numbers gives the same result. In other words, a is different
    from b if and only if there is a rational number c between a and b,
    but not equal to either a or b. When computing something this
    principle is clumsy, but for proofs it works quit well. Thanks
    to this ancients we able compute (and prove) a bunch of transcendental equalities. Theory was finished by Dededking and Cantor who proved
    that number produced by limiting process exist (earlier this was
    consider true "by faith" or by invoking geometric intuition).

    I think this needs some sorting. Speaking about "real numbers" in
    context of Eudoksos gives a wrong impression. The ancient Greeks
    expressed their mathematics in geometric properties and relations
    of such entities. (Algebra, Real Numbers, etc., came much later.)

    If you read modern articles you may find references to real numbers
    in context of ancient Greek mathematics, but these are only used to
    explain that old knowledge with modern methods.

    Janis


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Tuesday, January 27, 2026 18:44:15
    On 27/01/2026 17:31, Waldek Hebisch wrote:
    David Brown <david.brown@hesbynett.no> wrote:
    On 26/01/2026 21:34, wij wrote:
    On Mon, 2026-01-26 at 21:07 +0100, David Brown wrote:
    On 26/01/2026 16:51, wij wrote:
    On Mon, 2026-01-26 at 01:25 +0100, Janis Papanagnou wrote:
    (I probably regret answering to your post.)

    On 2026-01-25 18:20, wij wrote:

    You need to prove 4/33 exactly equal to 0.1212..., not approximation. >>>>>>
    Is that all you want proven; a specific example?

    This appears to be as trivial as the more general approach that James >>>>>> gave and that you (for reasons beyond me) don't accept (or don't see). >>>>>>
    First
    ÿÿÿÿÿ __
    ÿÿÿ 0.12ÿÿ orÿÿ 0.1212...

    are just finite representations of real numbers; conventions. And 4/33 >>>>>> is an expression representing an operation, the division. You can just >>>>>> do that computation (as you've certainly learned at school decades ago) >>>>>> in individual steps, continuing each step with the remainder

    ÿÿÿ 4/33 = 0ÿÿÿÿ => 0
    ÿÿÿ 40/33 = 1ÿÿÿ => 0.1
    ÿÿÿ remainder 7
    ÿÿÿ 70/33 = 2ÿÿÿ => 0.12
    ÿÿÿ remainder 4
    ÿÿÿ 40/33 = 1ÿÿÿ and at this point you see that the _operations_ *repeat*

    so the calculated decimals (1 and 2) will also repeat. And sensibly we >>>>>> need a finite representation (see above) to express that.

    ÿÿÿ Albert Einstein (for example) said: ?Die Definition von Wahnsinn ist,
    ÿÿÿ immer wieder das Gleiche zu tun und andere Ergebnisse zu erwarten?.

    Are you expecting the sequence of decimals differing at some point? >>>>>>
    If not you see that the number represented by the convention "0.1212..." >>>>>> equals to the number calculated or expressed by "4/33".

    Janis
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/download
    ÿÿÿÿÿÿÿÿÿ 3. 1/3 = 0.333... + non-zero-remainder (True identity. How to deny?)

    How would you deny it, and call the cut-off 'equation' identity?

    Have you ever heard of the concept of "limits" ?ÿ You might want to
    learn something about them before embarrassing yourself.

    What do you know about the concept of "limits"? (You invented? Don't try to be
    the next one, again. I remember the other expert in this forum has humiliated himself
    once, not sure which one, if I can safely predict. And I ignored the other reply,
    because it is tooÿobvious, I leave as record)


    No, I did not invent the concept of limits. Newton and Leibnitz were
    probably the first to use them, then Cauchy formalized them (if I
    remember my history correctly). But I /learned/ about them - understood
    them, understood proofs about them, understood how to use them.

    Actually, part that is needed here is ancient, due to Eudoksos. Namely,
    real numebers a and b are equal if and only if comparing them with
    rational numbers gives the same result. In other words, a is different
    from b if and only if there is a rational number c between a and b,
    but not equal to either a or b.

    Thanks for that - I was not familiar with his work. (My knowledge of
    the history of maths is mostly from whatever books, articles, Youtube
    videos, Wikipedia pages, etc., that I have looked at - so it is quite sporadic, and is often missing many of the great names. I have never
    done any kind of methodical study.) But of course mathematics is built
    up in stages - it's very rare that new concepts appear completely out of
    the blue. So it is natural that Newton and Leibnitz built on earlier
    work, through many other mathematicians, back to Eudoksos. And
    Eudoksos' work was an extension of earlier work on approximating pi, and
    so on.

    I always think it is fascinating that between any two distinct rationals
    there is at least one real number, and between any two distinct real
    numbers there is at least one ration number - and yet the cardinality of
    the reals is the power-set of the cardinality of the rational numbers.


    When computing something this
    principle is clumsy, but for proofs it works quit well. Thanks
    to this ancients we able compute (and prove) a bunch of transcendental equalities. Theory was finished by Dededking and Cantor who proved
    that number produced by limiting process exist (earlier this was
    consider true "by faith" or by invoking geometric intuition).


    Dedekind cuts are one of the ways to construct the real numbers -
    basically, filling in the gaps in the rationals by including the numbers produced by limiting processes in sets of rationals. So he did not
    really prove that these limits exist - he defined the reals to be these limits, and then proved that this formal definition of the real numbers
    worked the way everyone had assumed they worked.



    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From James Kuyper@3:633/10 to All on Monday, January 26, 2026 21:18:24
    On 26/01/2026 16:51, wij wrote:
    ...
    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/download
    3. 1/3 = 0.333... + non-zero-remainder (True identity. How to deny?)
    How would you deny it, and call the cut-off 'equation' identity?

    I deny it easily - the remainder is exactly 0.

    You cut off non-zero-remainder to stop repeating, so yes, you see the part you
    want to see, i.e. the front part without "...", and forgot the definition "infinitely repeat" is invalidated.

    There's no non-zero-remainder to cut off, nor is there any need to stop repeating. It repeats endlessly, and it is only because of the endless repetition that the remainder is 0. If it ever ended, the remainder
    would be non-zero, as you claim.

    The flaw is in your property 2, which claims that an infinite sum of
    rational numbers is not a rational number. That's unambiguously not the
    case in the standard real number system. Your proof of that claim is
    based upon asserting that the numerator and denominator of each step in
    the infinite series has a larger number of digits (which isn't
    necessarily true - but that's unimportant), but ignores the fact that
    the limit of an infinite sequence can have smaller numerators and
    denominators than the terms that make up the sequence.

    ...
    Prop 2= Repeating Q+Q infinitely does not yield rational number.
    (precisely, positive rational number)

    I dispute the validity of the proof of Prop 2.

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Wednesday, January 28, 2026 04:01:33
    On Mon, 2026-01-26 at 21:18 -0500, James Kuyper wrote:
    On 26/01/2026 16:51, wij wrote:
    ...
    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.t
    xt/download
    ÿÿÿÿÿÿÿÿÿ 3. 1/3 = 0.333
    ... + non-zero-remainder (True identity. How to deny?)
    How would you deny it, and call the cut-off 'equation' identity?

    I deny it easily - the remainder is exactly 0.

    You cut off non-zero-remainder to stop repeating, so yes, you see the p
    art you
    want to see, i.e. the front part without "...", and forgot the definiti
    on
    "infinitely repeat" is invalidated.

    There's no non-zero-remainder to cut off, nor is there any need to stop repeating. It repeats endlessly, and it is only because of the endless repetition that the remainder is 0. If it ever ended, the remainder
    would be non-zero, as you claim.

    Don't you see that you made a number of assertions beyond your standard all ows.
    "... can have smaller numerators and denominators..." ... How? Prove it, no
    t
    asserting it.

    The flaw is in your property 2, which claims that an infinite sum of
    rational numbers is not a rational number. That's unambiguously not the
    case in the standard real number system. Your proof of that claim is
    based upon asserting that the numerator and denominator of each step in
    the infinite series has a larger number of digits (which isn't
    necessarily true - but that's unimportant), but ignores the fact that
    the limit of an infinite sequence can have smaller numerators and denominators than the terms that make up the sequence.

    Accordingly, I suppose you deny this passage:

    // ... [cut]
    1. If 0.999... = 1 holds, then it can be proved that the unique
    prime
    factorization theorem of positive integers does not hold:
    0.999... = 999.../1000... = 9*(111...)/(5*2)*... =1
    <=> 3*3*(111...) = (5*2)*...
    The integer to the left of the equal sign contains the prime nu mber
    3, but the integer to the right cannot contain 3... Prime
    factorization is not unique.

    ...
    ÿÿÿÿÿÿÿ Prop 2= Repeating Q+Q infi
    nitely does not yield rational number.
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ?ÿÿÿ (precisely, positive rational number)

    I dispute the validity of the proof of Prop 2.

    No problem, you just need to prove it yourself.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Wednesday, January 28, 2026 04:08:59
    On Tue, 2026-01-27 at 09:21 +0100, David Brown wrote:
    On 26/01/2026 21:34, wij wrote:
    On Mon, 2026-01-26 at 21:07 +0100, David Brown wrote:
    On 26/01/2026 16:51, wij wrote:
    On Mon, 2026-01-26 at 01:25 +0100, Janis Papanagnou wrote:
    (I probably regret answering to your post.)

    On 2026-01-25 18:20, wij wrote:

    You need to prove 4/33 exactly equal to 0.1212..., not approxim
    ation.

    Is that all you want proven; a specific example?

    This appears to be as trivial as the more general approach that J
    ames
    gave and that you (for reasons beyond me) don't accept (or don't
    see).

    First
    ÿÿÿÿÿÿ __
    ÿÿÿÿ 0.12ÿÿ orÿÿ 0.1212..
    .

    are just finite representations of real numbers; conventions. And
    4/33
    is an expression representing an operation, the division. You can
    just
    do that computation (as you've certainly learned at school decade
    s ago)
    in individual steps, continuing each step with the remainder

    ÿÿÿÿ 4/33 = 0ÿÿÿÿ =>
    0
    ÿÿÿÿ 40/33 = 1ÿÿÿ => 0.1
    ÿÿÿÿ remainder 7
    ÿÿÿÿ 70/33 = 2ÿÿÿ => 0.12
    ÿÿÿÿ remainder 4
    ÿÿÿÿ 40/33 = 1ÿÿÿ and at thi
    s point you see that the _operations_ *repeat*

    so the calculated decimals (1 and 2) will also repeat. And sensib
    ly we
    need a finite representation (see above) to express that.

    ÿÿÿÿ Albert Einstein (for example) said: ?
    ??Die Definition von Wahnsinn ist,
    ÿÿÿÿ immer wieder das Gleiche zu tun und ande
    re Ergebnisse zu erwarten?.

    Are you expecting the sequence of decimals differing at some poin
    t?

    If not you see that the number represented by the convention "0.1
    212..."
    equals to the number calculated or expressed by "4/33".

    Janis
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-
    en.txt/download
    ÿÿÿÿÿÿÿÿÿÿ 3. 1/3
    = 0.333... + non-zero-remainder (True identity. How to deny?)

    How would you deny it, and call the cut-off 'equation' identity?

    Have you ever heard of the concept of "limits" ?ÿ You might want
    to
    learn something about them before embarrassing yourself.

    What do you know about the concept of "limits"? (You invented? Don't tr
    y to be
    the next one, again. I remember the other expert in this forum has humi
    liated himself
    once, not sure which one, if I can safely predict. And I ignored the ot
    her reply,
    because it is tooÿobvious, I leave as record)


    No, I did not invent the concept of limits.ÿ Newton and Leibnitz wer
    e
    probably the first to use them, then Cauchy formalized them (if I
    remember my history correctly).ÿ But I /learned/ about them - unders
    tood
    them, understood proofs about them, understood how to use them.

    And more importantly, I learned how mathematics works.ÿ I learned ho
    w to
    read proofs, and how to write proofs.ÿ So I know writing down some

    statement and claiming "True identity.ÿ How to deny?" does not
    constitute a proof.

    But I suspect any rational argument will fall on deaf ears here.ÿ Yo
    u
    don't understand mathematics, and instead think that you alone have reinvented it and every other mathematician current and historical was

    wrong.ÿ I would love to be able to help you and cure your delusions,
    but
    I have no idea how to do that.ÿ So I will just have to do as others

    have, and ignore you.


    Again, lots of talks to avoid you can prove what you say.
    You humiliated yourself again, sorry.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Lawrence D?Oliveiro@3:633/10 to All on Tuesday, January 27, 2026 22:52:30
    On Tue, 27 Jan 2026 16:31:47 -0000 (UTC), Waldek Hebisch wrote:

    Actually, part that is needed here is ancient, due to Eudoksos.
    Namely, real numebers a and b are equal if and only if comparing
    them with rational numbers gives the same result.

    They didn?t know about ?real? numbers back then. He was talking about ?irrational? numbers.

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Keith Thompson@3:633/10 to All on Tuesday, January 27, 2026 15:11:45
    David Brown <david.brown@hesbynett.no> writes:
    [...]
    But I suspect any rational argument will fall on deaf ears here. You
    don't understand mathematics, and instead think that you alone have reinvented it and every other mathematician current and historical was
    wrong. I would love to be able to help you and cure your delusions,
    but I have no idea how to do that. So I will just have to do as
    others have, and ignore you.

    And a good time to start would have been *before* posting a
    lengthy response.

    --
    Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
    void Void(void) { Void(); } /* The recursive call of the void */

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Tim Rentsch@3:633/10 to All on Tuesday, January 27, 2026 19:46:33
    wij <wyniijj5@gmail.com> writes:

    Prop 3: Recurring decimals are irrational numbers.

    This proposition is already known to be false from
    elementary (high school or earlier) algebra.

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Wednesday, January 28, 2026 12:34:56
    On Tue, 2026-01-27 at 19:46 -0800, Tim Rentsch wrote:
    wij <wyniijj5@gmail.com> writes:

    Prop 3:ÿ Recurring decimals are irrational numbers.

    This proposition is already known to be false from
    elementary (high school or earlier) algebra.

    Agree, but elementary (high school or earlier) algebra told a false proposi tion
    if Prop1, Prop2, Prop3 are true.

    In case another blind again, ignore what is there and still blindly repeati
    ng
    something who does not understand.
    If so, please post your proof (particularly about Prop1,Prop2,Prop3) or shu
    t up.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Wednesday, January 28, 2026 08:29:33
    On 27/01/2026 23:52, Lawrence D?Oliveiro wrote:
    On Tue, 27 Jan 2026 16:31:47 -0000 (UTC), Waldek Hebisch wrote:

    Actually, part that is needed here is ancient, due to Eudoksos.
    Namely, real numebers a and b are equal if and only if comparing
    them with rational numbers gives the same result.

    They didn?t know about ?real? numbers back then. He was talking about ?irrational? numbers.

    Indeed. They certainly knew about irrational numbers - according to
    legend, the first Greek to prove that the square root of 2 is not
    rational was killed for the heresy! But knowing that there are numbers
    that are not rational is not enough to complete the reals.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Janis Papanagnou@3:633/10 to All on Wednesday, January 28, 2026 10:27:41
    On 2026-01-28 08:29, David Brown wrote:
    On 27/01/2026 23:52, Lawrence D?Oliveiro wrote:
    On Tue, 27 Jan 2026 16:31:47 -0000 (UTC), Waldek Hebisch wrote:

    Actually, part that is needed here is ancient, due to Eudoksos.
    Namely, real numebers a and b are equal if and only if comparing
    them with rational numbers gives the same result.

    They didn?t know about ?real? numbers back then. He was talking about
    ?irrational? numbers.

    Indeed.ÿ They certainly knew about irrational numbers - [...]

    Erm.., no; as hinted upthread, not about "irrational *numbers*".
    (They worked with geometric entities, relations between these.)
    Modern texts sadly give a wrong impression, because they're not
    using the ancient methods to explain the Greek's mathematics but
    try to explain it with modern formulas, number systems, algebra.

    The sqrt(2) sample, as before for squares, pentagons, etc., they
    were looking for "gemeinsame Maá-Teilstrecke", as we call it here.
    If you see (modern) expressions like "AC^2 : AB^2 = a^2 : b^2"
    be aware that these terms and "operators" are just the algebraic
    counterparts of the respective geometric entities the Greeks had
    worked with. The graphical square ('^2') or relations (':'). And
    terms like even/odd in commensurability expressions were defined
    by "common unit subsections of lines" (not sure about the correct
    English term).

    (Have a look into Euklid's "Elements" to understand how they did
    their ancient mathematics.[*] Also a few modern books try to use
    more authentic representations; e.g. Nikiforowski/Freiman in the
    introductory "Predecessors" chapter. But the examples there are
    taken from Euklid's "Elements", so no wonder that it's authentic.)

    Janis

    [*] You'll find historic translations scanned and made available
    online (e.g. at archive.org).


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Ben Bacarisse@3:633/10 to All on Wednesday, January 28, 2026 17:34:13
    David Brown <david.brown@hesbynett.no> writes:

    On 26/01/2026 21:34, wij wrote:
    On Mon, 2026-01-26 at 21:07 +0100, David Brown wrote:
    On 26/01/2026 16:51, wij wrote:
    ...
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/download
    ????????? 3. 1/3 = 0.333... + non-zero-remainder (True
    identity. How to deny?)

    How would you deny it, and call the cut-off 'equation' identity?

    Have you ever heard of the concept of "limits" ?? You might want to
    learn something about them before embarrassing yourself.

    What do you know about the concept of "limits"? (You invented? Don't try
    to be
    the next one, again. I remember the other expert in this forum has
    humiliated himself
    once, not sure which one, if I can safely predict. And I ignored the
    other reply,
    because it is too?obvious, I leave as record)

    No, I did not invent the concept of limits. Newton and Leibnitz were probably the first to use them, then Cauchy formalized them (if I remember
    my history correctly). But I /learned/ about them - understood them, understood proofs about them, understood how to use them.

    This is a crank topic that annoys me so I will allow myself one more
    post in this wildly off-topic thread.

    Limits are not needed to show that 1/3 = 0.333... exactly. All that's
    needed is to know what 0.333... means. It means that, for every n, the
    nth fractional digit it 3. Obviously, if someone denies this you just
    have to give up, but if it is agreed that that is what the ... means
    then it's simple so show that there is no n (in N) for which the nth
    digit of 1/3 is not 3.

    --
    Ben.

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Richard Tobin@3:633/10 to All on Wednesday, January 28, 2026 18:23:11
    In article <871pj9tze2.fsf@bsb.me.uk>, Ben Bacarisse <ben@bsb.me.uk> wrote:

    Limits are not needed to show that 1/3 = 0.333... exactly. All
    that's needed is to know what 0.333... means. It means that, for
    every n, the nth fractional digit it 3. Obviously, if someone denies
    this you just have to give up, but if it is agreed that that is what
    the ... means then it's simple so show that there is no n (in N) for
    which the nth digit of 1/3 is not 3.

    I'm not convinced. The definition of a decimal number is the sum of
    its digits multiplied by the appropriate powers of 10, which for a non-terminating decimal is defined as a limit. You are implicitly
    using limits to even assert that there is a decimal representation of
    1/3.

    -- Richard

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Chris M. Thomasson@3:633/10 to All on Wednesday, January 28, 2026 12:59:20
    On 1/28/2026 1:27 AM, Janis Papanagnou wrote:
    On 2026-01-28 08:29, David Brown wrote:
    On 27/01/2026 23:52, Lawrence D?Oliveiro wrote:
    On Tue, 27 Jan 2026 16:31:47 -0000 (UTC), Waldek Hebisch wrote:

    Actually, part that is needed here is ancient, due to Eudoksos.
    Namely, real numebers a and b are equal if and only if comparing
    them with rational numbers gives the same result.

    They didn?t know about ?real? numbers back then. He was talking about
    ?irrational? numbers.

    Indeed.ÿ They certainly knew about irrational numbers - [...]

    Erm.., no; as hinted upthread, not about "irrational *numbers*".
    (They worked with geometric entities, relations between these.)
    Modern texts sadly give a wrong impression, because they're not
    using the ancient methods to explain the Greek's mathematics but
    try to explain it with modern formulas, number systems, algebra.

    The sqrt(2) sample, as before for squares, pentagons, etc., they
    were looking for "gemeinsame Maá-Teilstrecke", as we call it here.
    If you see (modern) expressions like "AC^2 : AB^2 = a^2 : b^2"
    be aware that these terms and "operators" are just the algebraic
    counterparts of the respective geometric entities the Greeks had
    worked with. The graphical square ('^2') or relations (':'). And
    terms like even/odd in commensurability expressions were defined
    by "common unit subsections of lines" (not sure about the correct
    English term).

    (Have a look into Euklid's "Elements" to understand how they did
    their ancient mathematics.[*] Also a few modern books try to use
    more authentic representations; e.g. Nikiforowski/Freiman in the
    introductory "Predecessors" chapter. But the examples there are
    taken from Euklid's "Elements", so no wonder that it's authentic.)

    Janis

    [*] You'll find historic translations scanned and made available
    online (e.g. at archive.org).


    A real with infinite precision can hold an irrational?

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Chris M. Thomasson@3:633/10 to All on Wednesday, January 28, 2026 13:02:38
    On 1/28/2026 9:34 AM, Ben Bacarisse wrote:
    David Brown <david.brown@hesbynett.no> writes:

    On 26/01/2026 21:34, wij wrote:
    On Mon, 2026-01-26 at 21:07 +0100, David Brown wrote:
    On 26/01/2026 16:51, wij wrote:
    ...
    Not quite sure what you mean.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/download
    ÿÿÿÿÿÿÿÿÿ 3. 1/3 = 0.333... + non-zero-remainder (True
    identity. How to deny?)

    How would you deny it, and call the cut-off 'equation' identity?

    Have you ever heard of the concept of "limits" ?ÿ You might want to
    learn something about them before embarrassing yourself.

    What do you know about the concept of "limits"? (You invented? Don't try >>> to be
    the next one, again. I remember the other expert in this forum has
    humiliated himself
    once, not sure which one, if I can safely predict. And I ignored the
    other reply,
    because it is tooÿobvious, I leave as record)

    No, I did not invent the concept of limits. Newton and Leibnitz were
    probably the first to use them, then Cauchy formalized them (if I remember >> my history correctly). But I /learned/ about them - understood them,
    understood proofs about them, understood how to use them.

    This is a crank topic that annoys me so I will allow myself one more
    post in this wildly off-topic thread.

    Limits are not needed to show that 1/3 = 0.333... exactly. All that's
    needed is to know what 0.333... means. It means that, for every n, the
    nth fractional digit it 3. Obviously, if someone denies this you just
    have to give up, but if it is agreed that that is what the ... means
    then it's simple so show that there is no n (in N) for which the nth
    digit of 1/3 is not 3.


    Once you start with long division, as soon as you hit a cycle, stop. 1/3
    hits a cycle rather quickly. So, 1/3 = 0.(3) Fair enough?

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Chris M. Thomasson@3:633/10 to All on Wednesday, January 28, 2026 13:04:11
    On 1/27/2026 7:46 PM, Tim Rentsch wrote:
    wij <wyniijj5@gmail.com> writes:

    Prop 3: Recurring decimals are irrational numbers.

    This proposition is already known to be false from
    elementary (high school or earlier) algebra.

    Indeed. Once you hit a cycle, its a rational...

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From David Brown@3:633/10 to All on Thursday, January 29, 2026 08:39:26
    On 28/01/2026 19:23, Richard Tobin wrote:
    In article <871pj9tze2.fsf@bsb.me.uk>, Ben Bacarisse <ben@bsb.me.uk> wrote:

    Limits are not needed to show that 1/3 = 0.333... exactly. All
    that's needed is to know what 0.333... means. It means that, for
    every n, the nth fractional digit it 3. Obviously, if someone denies
    this you just have to give up, but if it is agreed that that is what
    the ... means then it's simple so show that there is no n (in N) for
    which the nth digit of 1/3 is not 3.

    I'm not convinced. The definition of a decimal number is the sum of
    its digits multiplied by the appropriate powers of 10, which for a non-terminating decimal is defined as a limit. You are implicitly
    using limits to even assert that there is a decimal representation of
    1/3.


    That's the way I see it (but I am not a maths teacher or other
    mathematics professional). Ben's argument is correct to show "there is
    no n for which the nth digit of 1/3 is not 3". It is, however, not sufficient. It does not show that there is a decimal expansion for 1/3
    in the first place, or that the infinite repeating sequence makes sense
    - that requires limits (or some semblance of that concept).




    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Mike Terry@3:633/10 to All on Thursday, January 29, 2026 16:50:52
    On 24/01/2026 16:37, wij wrote:
    On Wed, 2025-12-24 at 20:05 +0800, wij wrote:


    I have just finished the script. Any defect,insufficiency, or typo?

    ------------------
    This file is intended a proof of Collatz Conjecture. The contents may be updated anytime. https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/download

    The text is converted by google translate with modest modification from https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-zh.txt/download
    Reader might want to try different translator or different settings.

    ----------------------------------------------------------------------------- Collatz function ::=

    int cop(int n) {
    if(n<=1) {
    if(n<1) {
    throw Error;
    }
    return 1; // 1 is the iteration endpoint
    }
    if(n%2) {
    return 3*n+1; // Odd number rule
    } else {
    return n/2; // Even number rule
    }
    }

    Collatz number: If an integer n, n?N<1,+1>, after the cop iteration will
    eventually calculate to 1 (i.e., cop(...cop(n))=1), then n is a Collatz
    number. Otherwise n is not a Collatz number.

    Collatz Problem: For each integer n, n?N<1,+1>, is n a Collatz number? IOW,
    the question is equivalent to asking whether the following procedure rcop
    terminates or not.

    void rcop(int n) {
    for(;n!=1;) {
    n=cop(n);
    }
    }

    Prop: cop(n) iteration contains no cycle (except for the '1-4-2-1' cycle, since
    1 is the termination condition).

    If you could prove just this much, you would become famous, at least amongst mathematicians!

    Proof: n can be decomposed into n= a+b. rcop(n) can be rewritten as rcop2(n):

    void rcop2(int n) {
    int a=n,b=0;
    for(;a+b!=1;) { // a+b= n in the cop iterative process.
    if((a%2)!=0) {
    --a; ++b; // Adjust a and b so that a remains even and the
    // following algorithm can be performed and remains
    // equivalent to cop(n) iteration.
    }
    if((b%2)!=0) { // Equivalent to (a+b)%2 (because a is even).
    a= 3*a;
    b= 3*b+1; // 3*(a+b)+1= (3*a) +(3*b+1)
    } else {
    a= a/2;
    b= b/2;
    }
    }
    }

    Let n?, a?, b? represent the values n,a, and b in the iteration.
    Assume that the cop(n) iteration is cyclic. The cycle is a fixed-length
    sequence, and the process must contain the operations 3x+1 and x/2 (and
    the associated operations --a and ++b, unless n is a 2^x number, but such
    numbers do not cycle). Let the cyclic sequence of n be:
    n?, n?, n?, ..., n? (n=n?).
    Because --a and ++b are continuously interpolated during the cycle, if

    I think "interpolated" is not the right word. Not sure exactly what is being claimed, but maybe
    this doesn't matter - check my next comment...

    a??0, then b? and n?=a?+b? will increase infinitely, contradicting the
    assumption that n? is cyclic. Therefore, a?=0 must hold during the cycle,

    Regardless of your reasoning, it is clear (and easily proved) that as the cycle repeats, a? at the
    same point in the cycle must decrease until it becomes zero. At this point a? remains zero for all
    further i, and no more --a,++b operations occur. (So there can only be finitely many such ops, but
    I agree a? has to become zero, which seems to be what you want to claim.)


    but the condition of a?=0 only exists in 1-4-2-1, a?=0 cannot cause the
    non-1-4-2-1 cycle of n?,n?,n?,...,n?.

    That doesn't follow from anything you've said so far. So this proof will not make you famous. Maybe
    you can work on this and fill in the gap. You need an earlier "Prop: If a?=0 then b? <= 4" or
    equivalent". Then you can be famous!

    It does seem to be the case with numbers I've tried [n up to 30,000,000 ish], that a? only becomes
    zero when we hit the final 1-4-2-1 cycle, so your claim is plausibly /true/, but that's not a
    /proof/ in any sense, of course.

    Therefore, we can conclude that cop(n) iterations are non-cyclic.

    Prop: For any n?N<1,+1>, the cop iteration operation terminates.
    Proof: Since an odd number n will always become even immediately after the
    cop iteration, it must undergo n/2 iterations. Therefore, we have an
    equivalent rcop3:

    void rcop3(int n) {
    int a=n,b=0;
    for(; a+b!=1;) {
    if((a%2)!=0) {
    --a; ++b;
    }
    // a/b measure point A
    if((b%2)!=0) {
    a= 3*a;
    b= 3*b+1;
    }
    a= a/2;
    b= b/2;
    }
    }

    Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    operation is paired with only one even operation (the actual ratio is 1.5
    even operations, but 1.5 is a statistical value; the decisive inference
    can only take the guaranteed value of 1). Then, at measurement point A,
    we have:

    a? = n-1
    a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    b? = 1
    b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    This is just an approximation, not exact. It is not hard to get the exact value, since you seem to
    know about geometric series...

    a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    = ... = (n-1)/(2-1/(3/2)???)

    Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2.

    I agree with this value (n-1)/2, /given your assumptions/ :
    - n odd
    - no --a operations
    - every odd op is followed by exactly one even op.

    But those assumptions are impossible in a real example, and real sequences will include multiple
    even ops and/or --a ops.

    OTOH all sequences have a?/b? as non-increasing, so a?/b? will reach zero (and stay there) or
    converge to some other limit value >= 0. In the latter case, you have not shown that that limit
    value will be (n-1)/2. (Hopefully your argument below does not depend on the particular value to
    which it converges?)

    (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    may also include --a and ++b operations, so the actual value of a?/b?
    will converge faster than the formula)

    It must converge, but not necessarily to (n-1)/2 ...

    After this point your argument seems to lose focus, and the notation is wrong!


    Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    => b = (a+b)/(r+1)

    ok this is simple algebra for any /specific/ iteration value of n,a,b. These values are changing as
    we iterate...

    Assuming the cop(n) iteration does not terminate, and m is one of the
    number in the iteration sequence. Therefore, we can derive the
    following:
    => b = m/(r+1)

    True for m,b,r for /that specific iteration/.

    => The limit of r+1 = (m-1)/2 + 1 = (m+1)/2
    => b = (2*m)/(m+1) = 2/(1+1/m)
    => b = 2 (the limit of b. At least it is known that m will be a large
    number)

    No that's not right - you're mixing values of m,b,r with those for later iterations of cop() and
    with limits. Also you're assuming r-->(m-1)/2. That was a specific result given your (impossible)
    assumptions listed above. In general r /does/ converge, but might converge to some other number, or
    become zero (in which case it also converges to zero so it's still true r converges). That is,
    unless you find a way to fix your proof to prove otherwise...

    To avoid confusing m,b,r as you've defined them with later iterations of cop(), best to call the
    values for later iterations m?,b?,r? or similar. And assume r?-->R (e.g.).

    So:
    The limit of r+1 = R+1 // with possibility R=0
    b? = m?/(r?+1)
    lim b? = lim m? / (R+1)
    ... EXCEPT that you have not shown that m? converges, so that last line is nonsense - we only use
    'lim' symbol when we the limits are known to exist...


    Since there is a limit (the numerical value is not important),

    ??? a limit to what? r? ---> R, but it seems you're trying to argue b? converges? That's not
    plausible. You can see this must be wrong, just from your earlier (overly) simplified sequence for
    which you originally calculated R = (n-1)/2. In that calculation you wrote:

    b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    and it is clear that b? is growing in an unbounded fashionry, not converging to b=2. You've just
    got muddled... Note: I don't necessarily agree with this b? formula - it looks to be only an
    approximation, but I do agree with your a?/b? limit [with your given assumptions].

    the
    iteration involves an infinite number of iterations of --a, a will
    inevitably become zero, so the iteration cannot fail to meet the
    iteration termination contion.

    That is also not right - once a? becomes zero, there will be /no more --a operations, so there can't
    be infinitely many of them!

    Regardless:

    1. IF there are infinitely many iterations of --a, they can be interspersed
    with a *= 3 operations, so it does not follow (just from what you've said)
    that a /must/ become zero.
    2. If a does become zero, it does not follow that the 1-4-2-1 loop has been
    encountered, unless you have some argument to prove that. [This is
    the same problem as with your earlier "no cycles" proof.]


    If n is even, then repeating the even operation (a finite number of times)
    cop(n) will yield an odd number without affecting the termination result
    as stated above. Therefore, the proposition is proved.

    ..aside from fixing the problems above.


    Mike.

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Friday, January 30, 2026 05:40:49
    On Thu, 2026-01-29 at 16:50 +0000, Mike Terry wrote:
    On 24/01/2026 16:37, wij wrote:
    On Wed, 2025-12-24 at 20:05 +0800, wij wrote:


    I have just finished the script. Any defect,insufficiency, or typo?

    ------------------
    This file is intended a proof of Collatz Conjecture. The contents may b
    e
    updated anytime. https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.tx
    t/download

    The text is converted by google translate with modest modification from https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-zh.tx
    t/download
    Reader might want to try different translator or different settings.

    -----------------------------------------------------------------------
    ------
    Collatz function ::=

    ÿÿÿÿÿÿ int cop(int n) {
    ÿÿÿÿÿÿÿÿ if(n<=1) {
    ÿÿÿÿÿÿÿÿÿÿ if(n<1) {
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? throw Error;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ return 1;
    ÿÿÿÿ // 1 is the iteration endpoint
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿ if(n%2) {
    ÿÿÿÿÿÿÿÿÿÿ return 3*n
    +1; // Odd number rule
    ÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿ return n/2
    ;ÿÿ // Even number rule
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ
    Collatz number: If an integer n, n?N<1,+1>, after the cop itera
    tion will
    ÿÿÿÿ eventually calculate to 1 (i.e., cop(...cop(n)
    )=1), then n is a Collatz
    ÿÿÿÿ number. Otherwise n is not a Collatz number.
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ?
    Collatz Problem: For each integer n, n?N<1,+1>, is n a Collatz
    number? IOW,
    ÿÿÿÿ the question is equivalent to asking whether t
    he following procedure rcop
    ÿÿÿÿ terminates or not.
    ÿÿÿÿÿÿ
    ÿÿÿÿÿÿ void rcop(int n) {
    ÿÿÿÿÿÿÿÿ for(;n!=1;) {
    ÿÿÿÿÿÿÿÿÿÿ n=cop(n)
    ;
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ
    Prop: cop(n) iteration contains no cycle (except for the '1-4-2-1' cycl
    e, since
    ÿÿÿÿÿ 1 is the termination condition).

    If you could prove just this much, you would become famous, at least amon
    gst mathematicians!

    ÿÿ Proof: n can be decomposed into n= a+b. rcop(n) can be r
    ewritten as rcop2(n):
    ÿÿÿÿÿÿ
    ÿÿÿÿÿÿ void rcop2(int n) {
    ÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿ for(;a+b!=1;) { // a
    +b= n in the cop iterative process.
    ÿÿÿÿÿÿÿÿÿÿ if((a%2)!
    =0) {
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? --a; ++b;ÿ // Adjust a and b so that a remains even and the
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ?ÿÿÿÿÿÿÿÿÿÿÿ // fo
    llowing algorithm can be performed and remains
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ?ÿÿÿÿÿÿÿÿÿÿÿ // eq
    uivalent to cop(n) iteration.
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ if((b%2)!
    =0) { // Equivalent to (a+b)%2 (because a is even).
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? b= 3*b+1;ÿÿÿ // 3*(a+b)+1= (3*a) +(3*b+1)
    ÿÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? b= b/2;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    ÿÿÿÿÿÿ Let n?, a?, b?
    ?? represent the values n,a, and b in the iteration.
    ÿÿÿÿÿÿ Assume that the cop(n) iteration i
    s cyclic. The cycle is a fixed-length
    ÿÿÿÿÿÿ sequence, and the process must con
    tain the operations 3x+1 and x/2 (and
    ÿÿÿÿÿÿ the associated operations --a and
    ++b, unless n is a 2^x number, but such
    ÿÿÿÿÿÿ numbers do not cycle). Let the cyc
    lic sequence of n be:
    ÿÿÿÿÿÿÿÿ n?, n?
    , n?, ..., n? (n=n?).
    ÿÿÿÿÿÿ Because --a and ++b are continuous
    ly interpolated during the cycle, if

    I think "interpolated" is not the right word.ÿ Not sure exactly what
    is being claimed, but maybe
    this doesn't matter - check my next comment...

    ÿÿÿÿÿÿ a??0, then b?
    ? and n?=a?+b? will increase infinitely, contra
    dicting the
    ÿÿÿÿÿÿ assumption that n? is cycl
    ic. Therefore, a?=0 must hold during the cycle,

    Regardless of your reasoning, it is clear (and easily proved) that as the
    cycle repeats, a? at the
    same point in the cycle must decrease until it becomes zero.ÿ At thi
    s point a? remains zero for all
    further i, and no more --a,++b operations occur.ÿ (So there can only
    be finitely many such ops, but
    I agree a? has to become zero, which seems to be what you want to
    claim.)


    ÿÿÿÿÿÿ but the condition of a?=
    0 only exists in 1-4-2-1, a?=0 cannot cause the
    ÿÿÿÿÿÿ non-1-4-2-1 cycle of n?,n
    ?,n?,...,n?.

    That doesn't follow from anything you've said so far.ÿ So this proof
    will not make you famous. Maybe
    you can work on this and fill in the gap.ÿ You need an earlier "Prop
    : If a?=0 then b? <= 4" or
    equivalent".ÿ Then you can be famous!

    It does seem to be the case with numbers I've tried [n up to 30,000,000 i
    sh], that a? only becomes
    zero when we hit the final 1-4-2-1 cycle, so your claim is plausibly /tru
    e/, but that's not a
    /proof/ in any sense, of course.

    ÿÿÿÿÿÿ Therefore, we can conclude that co
    p(n) iterations are non-cyclic.

    Prop: For any n?N<1,+1>, the cop iteration operation terminates
    .
    ÿÿ Proof: Since an odd number n will always become even immed
    iately after the
    ÿÿÿÿÿÿ cop iteration, it must undergo n/2
    iterations. Therefore, we have an
    ÿÿÿÿÿÿ equivalent rcop3:

    ÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿ if((a%2)!
    =0) {
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ // a/b mea
    sure point A
    ÿÿÿÿÿÿÿÿÿÿ if((b%2)!
    =0) {
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    ÿÿÿÿÿÿ Let n be odd and there be no `--a`
    , `++b` process. Assume that each odd
    ÿÿÿÿÿÿ operation is paired with only one
    even operation (the actual ratio is 1.5
    ÿÿÿÿÿÿ even operations, but 1.5 is a stat
    istical value; the decisive inference
    ÿÿÿÿÿÿ can only take the guaranteed value
    of 1). Then, at measurement point A,
    ÿÿÿÿÿÿ we have:

    ÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿ a? = (3*a??
    ??)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿ b? = (3*b??
    ??+1)/2 = ... = 2*(3/2)??? -1

    This is just an approximation, not exact.ÿ It is not hard to get the
    exact value, since you seem to
    know about geometric series...

    ÿÿÿÿÿÿ a?/b? = (a?
    ???)/(b???) = ((n-1)*(3/2)?
    ???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ? = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿ Interim summary: a?/b?
    ?? < a???/b??? and lim{
    ì} a?/b? = (n-1)/2.

    I agree with this value (n-1)/2, /given your assumptions/ :
    -ÿÿ n odd
    -ÿÿ no --a operations
    -ÿÿ every odd op is followed by exactly one even op.

    But those assumptions are impossible in a real example, and real sequence
    s will include multiple
    even ops and/or --a ops.

    OTOH all sequences have a?/b? as non-increasing, so a?
    ??/b? will reach zero (and stay there) or
    converge to some other limit value >= 0.ÿ In the latter case, you
    have not shown that that limit
    value will be (n-1)/2.ÿ (Hopefully your argument below does not depe
    nd on the particular value to
    which it converges?)

    ÿÿÿÿÿÿÿÿ (After eight iteration
    s, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿ may also include
    --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿ will converge fa
    ster than the formula)

    It must converge, but not necessarily to (n-1)/2 ...

    After this point your argument seems to lose focus, and the notation is w
    rong!


    ÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/
    b = a/b+1 = r+1
    ÿÿÿÿÿÿ => b = (a+b)/(r+1)

    ok this is simple algebra for any /specific/ iteration value of n,a,b.?
    ? These values are changing as
    we iterate...

    ÿÿÿÿÿÿ Assuming the cop(n) iteration does
    not terminate, and m is one of the
    ÿÿÿÿÿÿ number in the iteration sequence.
    Therefore, we can derive the
    ÿÿÿÿÿÿ following:
    ÿÿÿÿÿÿ => b = m/(r+1)

    True for m,b,r for /that specific iteration/.

    ÿÿÿÿÿÿ => The limit of r+1 = (m-1)/2
    + 1 = (m+1)/2
    ÿÿÿÿÿÿ => b = (2*m)/(m+1) = 2/(1+1/
    m)
    ÿÿÿÿÿÿ => b = 2 (the limit of b. At l
    east it is known that m will be a large
    ÿÿÿÿÿÿÿÿÿÿÿ?
    ?ÿÿÿÿ number)

    No that's not right - you're mixing values of m,b,r with those for later
    iterations of cop() and
    with limits.ÿ Also you're assuming r-->(m-1)/2.ÿ That was a spe
    cific result given your (impossible)
    assumptions listed above.ÿ In general r /does/ converge, but might c
    onverge to some other number, or
    become zero (in which case it also converges to zero so it's still true r
    converges).ÿ That is,
    unless you find a way to fix your proof to prove otherwise...

    To avoid confusing m,b,r as you've defined them with later iterations of
    cop(), best to call the
    values for later iterations m?,b?,r? or similar.
    ÿ And assume r?-->R (e.g.).

    So:
    ÿÿÿ The limit of r+1 = R+1ÿÿÿÿÿ
    ÿ // with possibility R=0
    ÿÿÿ b? = m?/(r?+1)
    ÿÿÿ lim b? = lim m? / (R+1)
    ... EXCEPT that you have not shown that m? converges, so that las
    t line is nonsense - we only use
    'lim' symbol when we the limits are known to exist...


    ÿÿÿÿÿÿ Since there is a limit (the numeri
    cal value is not important),

    ??? a limit to what?ÿ r? ---> R, but it seems you're trying
    to argue b? converges?ÿ That's not
    plausible.ÿ You can see this must be wrong, just from your earlier (
    overly) simplified sequence for
    which you originally calculated R = (n-1)/2. In that calculation you wr
    ote:

    ÿÿÿÿ b? = (3*b???+1
    )/2 = ... = 2*(3/2)??? -1

    and it is clear that b? is growing in an unbounded fashionry, not
    converging to b=2.ÿ You've just
    got muddled...ÿ Note: I don't necessarily agree with this b?
    formula - it looks to be only an
    approximation, but I do agree with your a?/b? limit [with
    your given assumptions].

    ÿÿÿÿÿÿ the
    ÿÿÿÿÿÿ iteration involves an infinite num
    ber of iterations of --a, a will
    ÿÿÿÿÿÿ inevitably become zero, so the ite
    ration cannot fail to meet the
    ÿÿÿÿÿÿ iteration termination contion.

    That is also not right - once a? becomes zero, there will be /no
    more --a operations, so there can't
    be infinitely many of them!

    Regardless:

    1.ÿ IF there are infinitely many iterations of --a, they can be inte
    rspersed
    ÿÿÿÿ with a *= 3 operations, so it does not follow
    (just from what you've said)
    ÿÿÿÿ that a /must/ become zero.
    2.ÿ If a does become zero, it does not follow that the 1-4-2-1 loop
    has been
    ÿÿÿÿ encountered, unless you have some argument to pr
    ove that.ÿ [This is
    ÿÿÿÿ the same problem as with your earlier "no cycles
    " proof.]


    ÿÿÿÿÿÿ If n is even, then repeating the e
    ven operation (a finite number of times)
    ÿÿÿÿÿÿ cop(n) will yield an odd number wi
    thout affecting the termination result
    ÿÿÿÿÿÿ as stated above. Therefore, the pr
    oposition is proved.

    ..aside from fixing the problems above.


    Mike.

    I agree with many point of your criticism, it is helpful.
    Since your comments are on the original script, I will post the updated ver sion to avoid
    unnecessary reply.

    --- [quote from the finalized version]
    Prop: ....[cut]
    void rcop3(int n) {
    int a=n,b=0;
    for(; a+b!=1;) {
    if((a%2)!=0) {
    --a; ++b;
    }
    // a/b measure point A
    if((b%2)!=0) {
    a= 3*a;
    b= 3*b+1;
    }
    a= a/2;
    b= b/2;
    }
    }

    The following proof demonstrates:
    1. The ratio a/b is decreasing.
    2. b has limit.
    3. a must decrease to below b because of the above reasons.
    4. Done, n=a+b has limit (cop(n) is known to terminate for n<2?
    ?? at
    least).

    Let n be odd and there be no `--a`, `++b` process. Assume that each o
    dd
    operation is paired with only one even operation, then, at measuremen
    t
    point A, we have:

    a? = n-1
    a? = (3*a???)/2 = ... = (n-1)*(
    3/2)???
    b? = 1
    b? = (3*b???+1)/2 = ... = 2*(3/
    2)??? -1
    a?/b? = (a???)/(b?
    ??) = ((n-1)*(3/2)???)/(2*(3
  • From wij@3:633/10 to All on Friday, January 30, 2026 08:29:40
    On Mon, 2026-01-26 at 01:20 +0800, wij wrote:
    On Sun, 2026-01-25 at 11:25 -0500, James Kuyper wrote:
    On Sun, 25 Jan 2026 13:28:31 +0800, wij wrote:

    On Sat, 2026-01-24 at 23:06 -0500, James Kuyper wrote:

    This generalizes to work with any recurring decimal. When the recurrence is n digits long (in the above example, n=2), just
    multiply by 10^n.

    Such arithmetic is called approximation ...

    So what is, in your opinion, the exact representation of 4/33 as a
    decimal fraction? Marking it as infinitely repeating means that it is
    not in any sense an approximation - it is exact.

    You need to prove 4/33 exactly equal to 0.1212..., not approximation.
    But,...

    ÿIf it were an
    approximation, there would be a finite difference between 4/33 and 0.1212.... How big is that difference? No matter how small of a finite difference you might think it has, going to infinitely many decimal
    digits makes the actual difference smaller than that.

    Yes, the same as infinity/infinitesimal.

    Keep in mind that, in the absence of specification to the contrary,
    we're talking about the standard real number system, not one of those alternatives that extends the real number system by adding
    infinitesimals, such as the surreals or the hyperreals.

    Trueÿif you are not referring to the current 'standard real number s
    ystem'.
    What else? (doesn't sound to contain much information)

    The standard real number system is not a constant thing, it will correct itself. Not even religion is constant.

    To be explicitly 'C' related, I remember people talking about what INF?
    ?
    should mean (an option may be merely for signifying overflow), I would suggest reserve the bit, not mixing with other meaning.

    Prop2 had rewrote (easier for older high schools to understand).

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/d ownload
    ....[cut]
    Prop 2: ?+?=? (the sum of a rational number and a
    rational number is still a
    rational number). The statement holds only for a finite number of
    addition steps.
    Proof: The addition of positive rational number q is strictly increasing.
    The
    result is either 'divergent' or 'convergent'. Both contain infinit
    ely
    long 'natural number' (otherwise they cannot be called 'convergent
    ' or
    'divergent').
    ----------

    Therefore, real number contains infinity (so infinitesimal).
    So, INFINITY is another real number, don't mix it with something else.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Mike Terry@3:633/10 to All on Friday, January 30, 2026 02:20:53
    On 29/01/2026 21:40, wij wrote:
    On Thu, 2026-01-29 at 16:50 +0000, Mike Terry wrote:
    On 24/01/2026 16:37, wij wrote:
    On Wed, 2025-12-24 at 20:05 +0800, wij wrote:


    I have just finished the script. Any defect,insufficiency, or typo?

    ------------------
    This file is intended a proof of Collatz Conjecture. The contents may be >>> updated anytime.
    https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/download

    The text is converted by google translate with modest modification from
    https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-zh.txt/download
    Reader might want to try different translator or different settings.

    -----------------------------------------------------------------------------
    Collatz function ::=

    ÿÿÿÿÿÿ int cop(int n) {
    ÿÿÿÿÿÿÿÿ if(n<=1) {
    ÿÿÿÿÿÿÿÿÿÿ if(n<1) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ throw Error;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ return 1;ÿÿÿÿ // 1 is the iteration endpoint
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿ if(n%2) {
    ÿÿÿÿÿÿÿÿÿÿ return 3*n+1; // Odd number rule
    ÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿ return n/2;ÿÿ // Even number rule
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    Collatz number: If an integer n, n?N<1,+1>, after the cop iteration will >>> ÿÿÿÿ eventually calculate to 1 (i.e., cop(...cop(n))=1), then n is a Collatz
    ÿÿÿÿ number. Otherwise n is not a Collatz number.

    Collatz Problem: For each integer n, n?N<1,+1>, is n a Collatz number? IOW, >>> ÿÿÿÿ the question is equivalent to asking whether the following procedure rcop
    ÿÿÿÿ terminates or not.

    ÿÿÿÿÿÿ void rcop(int n) {
    ÿÿÿÿÿÿÿÿ for(;n!=1;) {
    ÿÿÿÿÿÿÿÿÿÿ n=cop(n);
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    Prop: cop(n) iteration contains no cycle (except for the '1-4-2-1' cycle, since
    ÿÿÿÿÿ 1 is the termination condition).

    If you could prove just this much, you would become famous, at least amongst mathematicians!

    ÿÿ Proof: n can be decomposed into n= a+b. rcop(n) can be rewritten as rcop2(n):

    ÿÿÿÿÿÿ void rcop2(int n) {
    ÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿ for(;a+b!=1;) { // a+b= n in the cop iterative process.
    ÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;ÿ // Adjust a and b so that a remains even and the >>> ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // following algorithm can be performed and remains
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // equivalent to cop(n) iteration.
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) { // Equivalent to (a+b)%2 (because a is even). >>> ÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;ÿÿÿ // 3*(a+b)+1= (3*a) +(3*b+1)
    ÿÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    ÿÿÿÿÿÿ Let n?, a?, b? represent the values n,a, and b in the iteration. >>> ÿÿÿÿÿÿ Assume that the cop(n) iteration is cyclic. The cycle is a fixed-length
    ÿÿÿÿÿÿ sequence, and the process must contain the operations 3x+1 and x/2 (and
    ÿÿÿÿÿÿ the associated operations --a and ++b, unless n is a 2^x number, but such
    ÿÿÿÿÿÿ numbers do not cycle). Let the cyclic sequence of n be:
    ÿÿÿÿÿÿÿÿ n?, n?, n?, ..., n? (n=n?).
    ÿÿÿÿÿÿ Because --a and ++b are continuously interpolated during the cycle, if

    I think "interpolated" is not the right word.ÿ Not sure exactly what is being claimed, but maybe
    this doesn't matter - check my next comment...

    ÿÿÿÿÿÿ a??0, then b? and n?=a?+b? will increase infinitely, contradicting the
    ÿÿÿÿÿÿ assumption that n? is cyclic. Therefore, a?=0 must hold during the cycle,

    Regardless of your reasoning, it is clear (and easily proved) that as the cycle repeats, a? at the
    same point in the cycle must decrease until it becomes zero.ÿ At this point a? remains zero for all
    further i, and no more --a,++b operations occur.ÿ (So there can only be finitely many such ops, but
    I agree a? has to become zero, which seems to be what you want to claim.)


    ÿÿÿÿÿÿ but the condition of a?=0 only exists in 1-4-2-1, a?=0 cannot cause the
    ÿÿÿÿÿÿ non-1-4-2-1 cycle of n?,n?,n?,...,n?.

    That doesn't follow from anything you've said so far.ÿ So this proof will not make you famous. Maybe
    you can work on this and fill in the gap.ÿ You need an earlier "Prop: If a?=0 then b? <= 4" or
    equivalent".ÿ Then you can be famous!

    It does seem to be the case with numbers I've tried [n up to 30,000,000 ish], that a? only becomes
    zero when we hit the final 1-4-2-1 cycle, so your claim is plausibly /true/, but that's not a
    /proof/ in any sense, of course.

    ÿÿÿÿÿÿ Therefore, we can conclude that cop(n) iterations are non-cyclic. >>>
    Prop: For any n?N<1,+1>, the cop iteration operation terminates.
    ÿÿ Proof: Since an odd number n will always become even immediately after the
    ÿÿÿÿÿÿ cop iteration, it must undergo n/2 iterations. Therefore, we have an
    ÿÿÿÿÿÿ equivalent rcop3:

    ÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ // a/b measure point A
    ÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    ÿÿÿÿÿÿ Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    ÿÿÿÿÿÿ operation is paired with only one even operation (the actual ratio is 1.5
    ÿÿÿÿÿÿ even operations, but 1.5 is a statistical value; the decisive inference
    ÿÿÿÿÿÿ can only take the guaranteed value of 1). Then, at measurement point A,
    ÿÿÿÿÿÿ we have:

    ÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿ a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    This is just an approximation, not exact.ÿ It is not hard to get the exact value, since you seem to
    know about geometric series...

    ÿÿÿÿÿÿ a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿÿ = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿ Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2. >>
    I agree with this value (n-1)/2, /given your assumptions/ :
    -ÿÿ n odd
    -ÿÿ no --a operations
    -ÿÿ every odd op is followed by exactly one even op.

    But those assumptions are impossible in a real example, and real sequences will include multiple
    even ops and/or --a ops.

    OTOH all sequences have a?/b? as non-increasing, so a?/b? will reach zero (and stay there) or
    converge to some other limit value >= 0.ÿ In the latter case, you have not shown that that limit
    value will be (n-1)/2.ÿ (Hopefully your argument below does not depend on the particular value to
    which it converges?)

    ÿÿÿÿÿÿÿÿ (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿ may also include --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿ will converge faster than the formula)

    It must converge, but not necessarily to (n-1)/2 ...

    After this point your argument seems to lose focus, and the notation is wrong!


    ÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    ÿÿÿÿÿÿ => b = (a+b)/(r+1)

    ok this is simple algebra for any /specific/ iteration value of n,a,b.ÿ These values are changing as
    we iterate...

    ÿÿÿÿÿÿ Assuming the cop(n) iteration does not terminate, and m is one of the
    ÿÿÿÿÿÿ number in the iteration sequence. Therefore, we can derive the
    ÿÿÿÿÿÿ following:
    ÿÿÿÿÿÿ => b = m/(r+1)

    True for m,b,r for /that specific iteration/.

    ÿÿÿÿÿÿ => The limit of r+1 = (m-1)/2 + 1 = (m+1)/2
    ÿÿÿÿÿÿ => b = (2*m)/(m+1) = 2/(1+1/m)
    ÿÿÿÿÿÿ => b = 2 (the limit of b. At least it is known that m will be a large
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ number)

    No that's not right - you're mixing values of m,b,r with those for later iterations of cop() and
    with limits.ÿ Also you're assuming r-->(m-1)/2.ÿ That was a specific result given your (impossible)
    assumptions listed above.ÿ In general r /does/ converge, but might converge to some other number, or
    become zero (in which case it also converges to zero so it's still true r converges).ÿ That is,
    unless you find a way to fix your proof to prove otherwise...

    To avoid confusing m,b,r as you've defined them with later iterations of cop(), best to call the
    values for later iterations m?,b?,r? or similar.ÿ And assume r?-->R (e.g.). >>
    So:
    ÿÿÿ The limit of r+1 = R+1ÿÿÿÿÿÿ // with possibility R=0
    ÿÿÿ b? = m?/(r?+1)
    ÿÿÿ lim b? = lim m? / (R+1)
    ... EXCEPT that you have not shown that m? converges, so that last line is nonsense - we only use
    'lim' symbol when we the limits are known to exist...


    ÿÿÿÿÿÿ Since there is a limit (the numerical value is not important),

    ??? a limit to what?ÿ r? ---> R, but it seems you're trying to argue b? converges?ÿ That's not
    plausible.ÿ You can see this must be wrong, just from your earlier (overly) simplified sequence for
    which you originally calculated R = (n-1)/2. In that calculation you wrote: >>
    ÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    and it is clear that b? is growing in an unbounded fashionry, not converging to b=2.ÿ You've just
    got muddled...ÿ Note: I don't necessarily agree with this b? formula - it looks to be only an
    approximation, but I do agree with your a?/b? limit [with your given assumptions].

    ÿÿÿÿÿÿ the
    ÿÿÿÿÿÿ iteration involves an infinite number of iterations of --a, a will >>> ÿÿÿÿÿÿ inevitably become zero, so the iteration cannot fail to meet the >>> ÿÿÿÿÿÿ iteration termination contion.

    That is also not right - once a? becomes zero, there will be /no more --a operations, so there can't
    be infinitely many of them!

    Regardless:

    1.ÿ IF there are infinitely many iterations of --a, they can be interspersed >> ÿÿÿÿ with a *= 3 operations, so it does not follow (just from what you've said)
    ÿÿÿÿ that a /must/ become zero.
    2.ÿ If a does become zero, it does not follow that the 1-4-2-1 loop has been >> ÿÿÿÿ encountered, unless you have some argument to prove that.ÿ [This is
    ÿÿÿÿ the same problem as with your earlier "no cycles" proof.]


    ÿÿÿÿÿÿ If n is even, then repeating the even operation (a finite number of times)
    ÿÿÿÿÿÿ cop(n) will yield an odd number without affecting the termination result
    ÿÿÿÿÿÿ as stated above. Therefore, the proposition is proved.

    ..aside from fixing the problems above.


    Mike.

    I agree with many point of your criticism, it is helpful.
    Since your comments are on the original script, I will post the updated version to avoid
    unnecessary reply.

    --- [quote from the finalized version]
    Prop: ....[cut]
    void rcop3(int n) {
    int a=n,b=0;
    for(; a+b!=1;) {
    if((a%2)!=0) {
    --a; ++b;
    }
    // a/b measure point A
    if((b%2)!=0) {
    a= 3*a;
    b= 3*b+1;
    }
    a= a/2;
    b= b/2;
    }
    }

    The following proof demonstrates:
    1. The ratio a/b is decreasing.
    2. b has limit.
    3. a must decrease to below b because of the above reasons.
    4. Done, n=a+b has limit (cop(n) is known to terminate for n<2?? at
    least).

    Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    operation is paired with only one even operation, then, at measurement
    point A, we have:

    a? = n-1
    a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    b? = 1
    b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1
    a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    = ... = (n-1)/(2-1/(3/2)???)

    Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2.
    (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    may also include --a and ++b operations, so the actual value of a?/b?
    will converge faster than the formula)

    Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    => b = (a+b)/(r+1) = n/(r+1)
    After sufficient iterations:
    => The limit of r+1 = (n-1)/2 + 1 = (n+1)/2
    => b = (2*n)/(n+1) = 2/(1+1/n)
    => b = 2 (the limit of b. it is known that n is a large number)

    Since b has limit (the numerical value is not important), the iteration
    involves an infinite number of iterations of --a, a will inevitably become
    zero, so the iteration cannot fail to meet the iteration termination
    condition.
    ----------------------

    1. a/b ratio (formula) is a lower bound estimate as stated. In the real cases,
    it decreases faster.
    2. In the iteration, even ops does not change a/b ratio. Ops --a,++b only makes
    the ratio a/bÿmore decreasing.
    3. The proof only needs to show there is a limit. What value a/b converges does
    not important.

    So we agree a/b converges, but the updates above do not address any of the problems raised in my
    previous post...

    Mike.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Friday, January 30, 2026 11:03:05
    On Fri, 2026-01-30 at 02:20 +0000, Mike Terry wrote:
    On 29/01/2026 21:40, wij wrote:
    On Thu, 2026-01-29 at 16:50 +0000, Mike Terry wrote:
    On 24/01/2026 16:37, wij wrote:
    On Wed, 2025-12-24 at 20:05 +0800, wij wrote:


    I have just finished the script. Any defect,insufficiency, or typo?

    ------------------
    This file is intended a proof of Collatz Conjecture. The contents may be
    updated anytime. https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/download

    The text is converted by google translate with modest modification from https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-zh.txt/download
    Reader might want to try different translator or different settings.

    -----------------------------------------------------------------------------
    Collatz function ::=

    ÿÿÿÿÿÿÿ int cop(int n) {
    ÿÿÿÿÿÿÿÿÿ if(n<=1) {
    ÿÿÿÿÿÿÿÿÿÿÿ if(n<1) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ throw Error;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ return 1;ÿÿÿÿ // 1 is the iteration endpoint
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿ if(n%2) {
    ÿÿÿÿÿÿÿÿÿÿÿ return 3*n+1; // Odd number rule
    ÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿ return n/2;ÿÿ // Even number rule
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ
    Collatz number: If an integer n, n?N<1,+1>, after the cop iteration will
    ÿÿÿÿÿ eventually calculate to 1 (i.e., cop(...cop(n))=1), then n is a Collatz
    ÿÿÿÿÿ number. Otherwise n is not a Collatz number.
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ
    Collatz Problem: For each integer n, n?N<1,+1>, is n a Collatz number? IOW,
    ÿÿÿÿÿ the question is equivalent to asking whether the following procedure rcop
    ÿÿÿÿÿ terminates or not.
    ÿÿÿÿÿÿÿ
    ÿÿÿÿÿÿÿ void rcop(int n) {
    ÿÿÿÿÿÿÿÿÿ for(;n!=1;) {
    ÿÿÿÿÿÿÿÿÿÿÿ n=cop(n);
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ
    Prop: cop(n) iteration contains no cycle (except for the '1-4-2-1' cycle, since
    ÿÿÿÿÿÿ 1 is the termination condition).

    If you could prove just this much, you would become famous, at least amongst mathematicians!

    ÿÿÿ Proof: n can be decomposed into n= a+b. rcop(n) can be rewritten as rcop2(n):
    ÿÿÿÿÿÿÿ
    ÿÿÿÿÿÿÿ void rcop2(int n) {
    ÿÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿÿ for(;a+b!=1;) { // a+b= n in the cop iterative process.
    ÿÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;ÿ // Adjust a and b so that a remains even and the
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // following algorithm can be performed and remains
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // equivalent to cop(n) iteration.
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) { // Equivalent to (a+b)%2 (because a is even).
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;ÿÿÿ // 3*(a+b)+1= (3*a) +(3*b+1)
    ÿÿÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    ÿÿÿÿÿÿÿ Let n?, a?, b? represent the values n,a, and b in the iteration.
    ÿÿÿÿÿÿÿ Assume that the cop(n) iteration is cyclic. The cycle is a fixed-length
    ÿÿÿÿÿÿÿ sequence, and the process must contain the operations 3x+1 and x/2 (and
    ÿÿÿÿÿÿÿ the associated operations --a and ++b, unless n is a 2^x number, but such
    ÿÿÿÿÿÿÿ numbers do not cycle). Let the cyclic sequence of n be:
    ÿÿÿÿÿÿÿÿÿ n?, n?, n?, ..., n? (n=n?).
    ÿÿÿÿÿÿÿ Because --a and ++b are continuously interpolated during the cycle, if

    I think "interpolated" is not the right word.ÿ Not sure exactly what is being claimed, but maybe
    this doesn't matter - check my next comment...

    ÿÿÿÿÿÿÿ a??0, then b? and n?=a?+b? will increase infinitely, contradicting the
    ÿÿÿÿÿÿÿ assumption that n? is cyclic. Therefore, a?=0 must hold during the cycle,

    Regardless of your reasoning, it is clear (and easily proved) that as the cycle repeats, a? at
    the
    same point in the cycle must decrease until it becomes zero.ÿ At this point a? remains zero for
    all
    further i, and no more --a,++b operations occur.ÿ (So there can only be finitely many such ops,
    but
    I agree a? has to become zero, which seems to be what you want to claim.)


    ÿÿÿÿÿÿÿ but the condition of a?=0 only exists in 1-4-2-1, a?=0 cannot cause the
    ÿÿÿÿÿÿÿ non-1-4-2-1 cycle of n?,n?,n?,...,n?.

    That doesn't follow from anything you've said so far.ÿ So this proof will not make you famous.
    Maybe
    you can work on this and fill in the gap.ÿ You need an earlier "Prop: If a?=0 then b? <= 4" or
    equivalent".ÿ Then you can be famous!

    It does seem to be the case with numbers I've tried [n up to 30,000,000 ish], that a? only
    becomes
    zero when we hit the final 1-4-2-1 cycle, so your claim is plausibly /true/, but that's not a
    /proof/ in any sense, of course.

    ÿÿÿÿÿÿÿ Therefore, we can conclude that cop(n) iterations are non-cyclic.

    Prop: For any n?N<1,+1>, the cop iteration operation terminates.
    ÿÿÿ Proof: Since an odd number n will always become even immediately after the
    ÿÿÿÿÿÿÿ cop iteration, it must undergo n/2 iterations. Therefore, we have an
    ÿÿÿÿÿÿÿ equivalent rcop3:

    ÿÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ // a/b measure point A
    ÿÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    ÿÿÿÿÿÿÿ Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    ÿÿÿÿÿÿÿ operation is paired with only one even operation (the actual ratio is 1.5
    ÿÿÿÿÿÿÿ even operations, but 1.5 is a statistical value; the decisive inference
    ÿÿÿÿÿÿÿ can only take the guaranteed value of 1). Then, at measurement point A,
    ÿÿÿÿÿÿÿ we have:

    ÿÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿÿ a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    This is just an approximation, not exact.ÿ It is not hard to get the exact value, since you seem
    to
    know about geometric series...

    ÿÿÿÿÿÿÿ a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿÿ Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2.

    I agree with this value (n-1)/2, /given your assumptions/ :
    -ÿÿ n odd
    -ÿÿ no --a operations
    -ÿÿ every odd op is followed by exactly one even op.

    But those assumptions are impossible in a real example, and real sequences will include multiple
    even ops and/or --a ops.

    OTOH all sequences have a?/b? as non-increasing, so a?/b? will reach zero (and stay there) or
    converge to some other limit value >= 0.ÿ In the latter case, you have not shown that that limit
    value will be (n-1)/2.ÿ (Hopefully your argument below does not depend on the particular value
    to
    which it converges?)

    ÿÿÿÿÿÿÿÿÿ (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿÿ may also include --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿÿ will converge faster than the formula)

    It must converge, but not necessarily to (n-1)/2 ...

    After this point your argument seems to lose focus, and the notation is wrong!


    ÿÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    ÿÿÿÿÿÿÿ => b = (a+b)/(r+1)

    ok this is simple algebra for any /specific/ iteration value of n,a,b.ÿ These values are
    changing as
    we iterate...

    ÿÿÿÿÿÿÿ Assuming the cop(n) iteration does not terminate, and m is one of the
    ÿÿÿÿÿÿÿ number in the iteration sequence. Therefore, we can derive the
    ÿÿÿÿÿÿÿ following:
    ÿÿÿÿÿÿÿ => b = m/(r+1)

    True for m,b,r for /that specific iteration/.

    ÿÿÿÿÿÿÿ => The limit of r+1 = (m-1)/2 + 1 = (m+1)/2
    ÿÿÿÿÿÿÿ => b = (2*m)/(m+1) = 2/(1+1/m)
    ÿÿÿÿÿÿÿ => b = 2 (the limit of b. At least it is known that m will be a large
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ number)

    No that's not right - you're mixing values of m,b,r with those for later iterations of cop() and
    with limits.ÿ Also you're assuming r-->(m-1)/2.ÿ That was a specific result given your
    (impossible)
    assumptions listed above.ÿ In general r /does/ converge, but might converge to some other
    number, or
    become zero (in which case it also converges to zero so it's still true r converges).ÿ That is,
    unless you find a way to fix your proof to prove otherwise...

    To avoid confusing m,b,r as you've defined them with later iterations of cop(), best to call the
    values for later iterations m?,b?,r? or similar.ÿ And assume r?-->R (e.g.).

    So:
    ÿÿÿÿ The limit of r+1 = R+1ÿÿÿÿÿÿ // with possibility R=0
    ÿÿÿÿ b? = m?/(r?+1)
    ÿÿÿÿ lim b? = lim m? / (R+1)
    ... EXCEPT that you have not shown that m? converges, so that last line is nonsense - we only
    use
    'lim' symbol when we the limits are known to exist...


    ÿÿÿÿÿÿÿ Since there is a limit (the numerical value is not important),

    ??? a limit to what?ÿ r? ---> R, but it seems you're trying to argue b? converges?ÿ That's not
    plausible.ÿ You can see this must be wrong, just from your earlier (overly) simplified sequence
    for
    which you originally calculated R = (n-1)/2. In that calculation you wrote:

    ÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    and it is clear that b? is growing in an unbounded fashionry, not converging to b=2.ÿ You've
    just
    got muddled...ÿ Note: I don't necessarily agree with this b? formula - it looks to be only an
    approximation, but I do agree with your a?/b? limit [with your given assumptions].

    ÿÿÿÿÿÿÿ the
    ÿÿÿÿÿÿÿ iteration involves an infinite number of iterations of --a, a will
    ÿÿÿÿÿÿÿ inevitably become zero, so the iteration cannot fail to meet the
    ÿÿÿÿÿÿÿ iteration termination contion.

    That is also not right - once a? becomes zero, there will be /no more --a operations, so there
    can't
    be infinitely many of them!

    Regardless:

    1.ÿ IF there are infinitely many iterations of --a, they can be interspersed
    ÿÿÿÿÿ with a *= 3 operations, so it does not follow (just from what you've said)
    ÿÿÿÿÿ that a /must/ become zero.
    2.ÿ If a does become zero, it does not follow that the 1-4-2-1 loop has been
    ÿÿÿÿÿ encountered, unless you have some argument to prove that.ÿ [This is ÿÿÿÿÿ the same problem as with your earlier "no cycles" proof.]


    ÿÿÿÿÿÿÿ If n is even, then repeating the even operation (a finite number of times)
    ÿÿÿÿÿÿÿ cop(n) will yield an odd number without affecting the termination result
    ÿÿÿÿÿÿÿ as stated above. Therefore, the proposition is proved.

    ..aside from fixing the problems above.


    Mike.

    I agree with many point of your criticism, it is helpful.
    Since your comments are on the original script, I will post the updated version to avoid
    unnecessary reply.

    --- [quote from the finalized version]
    Prop:ÿÿ ....[cut]
    ÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ // a/b measure point A
    ÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    ÿÿÿÿÿÿ The following proof demonstrates:
    ÿÿÿÿÿÿÿÿ 1. The ratio a/b is decreasing.
    ÿÿÿÿÿÿÿÿ 2. b has limit.
    ÿÿÿÿÿÿÿÿ 3. a must decrease to below b because of the above reasons.
    ÿÿÿÿÿÿÿÿ 4. Done, n=a+b has limit (cop(n) is known to terminate for n<2?? at
    ÿÿÿÿÿÿÿÿÿÿÿ least).

    ÿÿÿÿÿÿ Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    ÿÿÿÿÿÿ operation is paired with only one even operation, then, at measurement
    ÿÿÿÿÿÿ point A, we have:

    ÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿ a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1
    ÿÿÿÿÿÿ a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿÿ = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿ Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2.
    ÿÿÿÿÿÿÿÿ (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿ may also include --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿ will converge faster than the formula)

    ÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    ÿÿÿÿÿÿ => b = (a+b)/(r+1) = n/(r+1)
    ÿÿÿÿÿÿ After sufficient iterations:
    ÿÿÿÿÿÿ => The limit of r+1 = (n-1)/2 + 1 = (n+1)/2
    ÿÿÿÿÿÿ => b = (2*n)/(n+1) = 2/(1+1/n)
    ÿÿÿÿÿÿ => b = 2 (the limit of b. it is known that n is a large number)

    ÿÿÿÿÿÿ Since b has limit (the numerical value is not important), the iteration
    ÿÿÿÿÿÿ involves an infinite number of iterations of --a, a will inevitably become
    ÿÿÿÿÿÿ zero, so the iteration cannot fail to meet the iteration termination ÿÿÿÿÿÿ condition.
    ----------------------

    1. a/b ratio (formula) is a lower bound estimate as stated. In the real cases,
    ÿÿÿ it decreases faster.
    2. In the iteration, even ops does not change a/b ratio. Ops --a,++b only makes
    ÿÿÿ the ratio a/bÿmore decreasing.
    3. The proof only needs to show there is a limit. What value a/b converges does
    ÿÿÿ not important.

    So we agree a/b converges, but the updates above do not address any of the problems raised in my
    previous post...

    Mike.
    Will you elaborate precisely?


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Friday, January 30, 2026 11:52:01
    On Fri, 2026-01-30 at 02:20 +0000, Mike Terry wrote:
    On 29/01/2026 21:40, wij wrote:
    On Thu, 2026-01-29 at 16:50 +0000, Mike Terry wrote:
    On 24/01/2026 16:37, wij wrote:
    On Wed, 2025-12-24 at 20:05 +0800, wij wrote:


    I have just finished the script. Any defect,insufficiency, or typo?

    ------------------
    This file is intended a proof of Collatz Conjecture. The contents may be
    updated anytime. https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/download

    The text is converted by google translate with modest modification from https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-zh.txt/download
    Reader might want to try different translator or different settings.

    -----------------------------------------------------------------------------
    Collatz function ::=

    ÿÿÿÿÿÿÿ int cop(int n) {
    ÿÿÿÿÿÿÿÿÿ if(n<=1) {
    ÿÿÿÿÿÿÿÿÿÿÿ if(n<1) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ throw Error;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ return 1;ÿÿÿÿ // 1 is the iteration endpoint
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿ if(n%2) {
    ÿÿÿÿÿÿÿÿÿÿÿ return 3*n+1; // Odd number rule
    ÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿ return n/2;ÿÿ // Even number rule
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ
    Collatz number: If an integer n, n?N<1,+1>, after the cop iteration will
    ÿÿÿÿÿ eventually calculate to 1 (i.e., cop(...cop(n))=1), then n is a Collatz
    ÿÿÿÿÿ number. Otherwise n is not a Collatz number.
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ
    Collatz Problem: For each integer n, n?N<1,+1>, is n a Collatz number? IOW,
    ÿÿÿÿÿ the question is equivalent to asking whether the following procedure rcop
    ÿÿÿÿÿ terminates or not.
    ÿÿÿÿÿÿÿ
    ÿÿÿÿÿÿÿ void rcop(int n) {
    ÿÿÿÿÿÿÿÿÿ for(;n!=1;) {
    ÿÿÿÿÿÿÿÿÿÿÿ n=cop(n);
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ
    Prop: cop(n) iteration contains no cycle (except for the '1-4-2-1' cycle, since
    ÿÿÿÿÿÿ 1 is the termination condition).

    If you could prove just this much, you would become famous, at least amongst mathematicians!

    ÿÿÿ Proof: n can be decomposed into n= a+b. rcop(n) can be rewritten as rcop2(n):
    ÿÿÿÿÿÿÿ
    ÿÿÿÿÿÿÿ void rcop2(int n) {
    ÿÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿÿ for(;a+b!=1;) { // a+b= n in the cop iterative process.
    ÿÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;ÿ // Adjust a and b so that a remains even and the
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // following algorithm can be performed and remains
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // equivalent to cop(n) iteration.
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) { // Equivalent to (a+b)%2 (because a is even).
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;ÿÿÿ // 3*(a+b)+1= (3*a) +(3*b+1)
    ÿÿÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    ÿÿÿÿÿÿÿ Let n?, a?, b? represent the values n,a, and b in the iteration.
    ÿÿÿÿÿÿÿ Assume that the cop(n) iteration is cyclic. The cycle is a fixed-length
    ÿÿÿÿÿÿÿ sequence, and the process must contain the operations 3x+1 and x/2 (and
    ÿÿÿÿÿÿÿ the associated operations --a and ++b, unless n is a 2^x number, but such
    ÿÿÿÿÿÿÿ numbers do not cycle). Let the cyclic sequence of n be:
    ÿÿÿÿÿÿÿÿÿ n?, n?, n?, ..., n? (n=n?).
    ÿÿÿÿÿÿÿ Because --a and ++b are continuously interpolated during the cycle, if

    I think "interpolated" is not the right word.ÿ Not sure exactly what is being claimed, but maybe
    this doesn't matter - check my next comment...

    ÿÿÿÿÿÿÿ a??0, then b? and n?=a?+b? will increase infinitely, contradicting the
    ÿÿÿÿÿÿÿ assumption that n? is cyclic. Therefore, a?=0 must hold during the cycle,

    Regardless of your reasoning, it is clear (and easily proved) that as the cycle repeats, a? at
    the
    same point in the cycle must decrease until it becomes zero.ÿ At this point a? remains zero for
    all
    further i, and no more --a,++b operations occur.ÿ (So there can only be finitely many such ops,
    but
    I agree a? has to become zero, which seems to be what you want to claim.)


    ÿÿÿÿÿÿÿ but the condition of a?=0 only exists in 1-4-2-1, a?=0 cannot cause the
    ÿÿÿÿÿÿÿ non-1-4-2-1 cycle of n?,n?,n?,...,n?.

    That doesn't follow from anything you've said so far.ÿ So this proof will not make you famous.
    Maybe
    you can work on this and fill in the gap.ÿ You need an earlier "Prop: If a?=0 then b? <= 4" or
    equivalent".ÿ Then you can be famous!

    It does seem to be the case with numbers I've tried [n up to 30,000,000 ish], that a? only
    becomes
    zero when we hit the final 1-4-2-1 cycle, so your claim is plausibly /true/, but that's not a
    /proof/ in any sense, of course.

    ÿÿÿÿÿÿÿ Therefore, we can conclude that cop(n) iterations are non-cyclic.

    Prop: For any n?N<1,+1>, the cop iteration operation terminates.
    ÿÿÿ Proof: Since an odd number n will always become even immediately after the
    ÿÿÿÿÿÿÿ cop iteration, it must undergo n/2 iterations. Therefore, we have an
    ÿÿÿÿÿÿÿ equivalent rcop3:

    ÿÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ // a/b measure point A
    ÿÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    ÿÿÿÿÿÿÿ Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    ÿÿÿÿÿÿÿ operation is paired with only one even operation (the actual ratio is 1.5
    ÿÿÿÿÿÿÿ even operations, but 1.5 is a statistical value; the decisive inference
    ÿÿÿÿÿÿÿ can only take the guaranteed value of 1). Then, at measurement point A,
    ÿÿÿÿÿÿÿ we have:

    ÿÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿÿ a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    This is just an approximation, not exact.ÿ It is not hard to get the exact value, since you seem
    to
    know about geometric series...

    ÿÿÿÿÿÿÿ a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿÿ Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2.

    I agree with this value (n-1)/2, /given your assumptions/ :
    -ÿÿ n odd
    -ÿÿ no --a operations
    -ÿÿ every odd op is followed by exactly one even op.

    But those assumptions are impossible in a real example, and real sequences will include multiple
    even ops and/or --a ops.

    OTOH all sequences have a?/b? as non-increasing, so a?/b? will reach zero (and stay there) or
    converge to some other limit value >= 0.ÿ In the latter case, you have not shown that that limit
    value will be (n-1)/2.ÿ (Hopefully your argument below does not depend on the particular value
    to
    which it converges?)

    ÿÿÿÿÿÿÿÿÿ (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿÿ may also include --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿÿ will converge faster than the formula)

    It must converge, but not necessarily to (n-1)/2 ...

    After this point your argument seems to lose focus, and the notation is wrong!


    ÿÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    ÿÿÿÿÿÿÿ => b = (a+b)/(r+1)

    ok this is simple algebra for any /specific/ iteration value of n,a,b.ÿ These values are
    changing as
    we iterate...

    ÿÿÿÿÿÿÿ Assuming the cop(n) iteration does not terminate, and m is one of the
    ÿÿÿÿÿÿÿ number in the iteration sequence. Therefore, we can derive the
    ÿÿÿÿÿÿÿ following:
    ÿÿÿÿÿÿÿ => b = m/(r+1)

    True for m,b,r for /that specific iteration/.

    ÿÿÿÿÿÿÿ => The limit of r+1 = (m-1)/2 + 1 = (m+1)/2
    ÿÿÿÿÿÿÿ => b = (2*m)/(m+1) = 2/(1+1/m)
    ÿÿÿÿÿÿÿ => b = 2 (the limit of b. At least it is known that m will be a large
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ number)

    No that's not right - you're mixing values of m,b,r with those for later iterations of cop() and
    with limits.ÿ Also you're assuming r-->(m-1)/2.ÿ That was a specific result given your
    (impossible)
    assumptions listed above.ÿ In general r /does/ converge, but might converge to some other
    number, or
    become zero (in which case it also converges to zero so it's still true r converges).ÿ That is,
    unless you find a way to fix your proof to prove otherwise...

    To avoid confusing m,b,r as you've defined them with later iterations of cop(), best to call the
    values for later iterations m?,b?,r? or similar.ÿ And assume r?-->R (e.g.).

    So:
    ÿÿÿÿ The limit of r+1 = R+1ÿÿÿÿÿÿ // with possibility R=0
    ÿÿÿÿ b? = m?/(r?+1)
    ÿÿÿÿ lim b? = lim m? / (R+1)
    ... EXCEPT that you have not shown that m? converges, so that last line is nonsense - we only
    use
    'lim' symbol when we the limits are known to exist...


    ÿÿÿÿÿÿÿ Since there is a limit (the numerical value is not important),

    ??? a limit to what?ÿ r? ---> R, but it seems you're trying to argue b? converges?ÿ That's not
    plausible.ÿ You can see this must be wrong, just from your earlier (overly) simplified sequence
    for
    which you originally calculated R = (n-1)/2. In that calculation you wrote:

    ÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    and it is clear that b? is growing in an unbounded fashionry, not converging to b=2.ÿ You've
    just
    got muddled...ÿ Note: I don't necessarily agree with this b? formula - it looks to be only an
    approximation, but I do agree with your a?/b? limit [with your given assumptions].

    ÿÿÿÿÿÿÿ the
    ÿÿÿÿÿÿÿ iteration involves an infinite number of iterations of --a, a will
    ÿÿÿÿÿÿÿ inevitably become zero, so the iteration cannot fail to meet the
    ÿÿÿÿÿÿÿ iteration termination contion.

    That is also not right - once a? becomes zero, there will be /no more --a operations, so there
    can't
    be infinitely many of them!

    Regardless:

    1.ÿ IF there are infinitely many iterations of --a, they can be interspersed
    ÿÿÿÿÿ with a *= 3 operations, so it does not follow (just from what you've said)
    ÿÿÿÿÿ that a /must/ become zero.
    2.ÿ If a does become zero, it does not follow that the 1-4-2-1 loop has been
    ÿÿÿÿÿ encountered, unless you have some argument to prove that.ÿ [This is ÿÿÿÿÿ the same problem as with your earlier "no cycles" proof.]


    ÿÿÿÿÿÿÿ If n is even, then repeating the even operation (a finite number of times)
    ÿÿÿÿÿÿÿ cop(n) will yield an odd number without affecting the termination result
    ÿÿÿÿÿÿÿ as stated above. Therefore, the proposition is proved.

    ..aside from fixing the problems above.


    Mike.

    I agree with many point of your criticism, it is helpful.
    Since your comments are on the original script, I will post the updated version to avoid
    unnecessary reply.

    --- [quote from the finalized version]
    Prop:ÿÿ ....[cut]
    ÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ // a/b measure point A
    ÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    ÿÿÿÿÿÿ The following proof demonstrates:
    ÿÿÿÿÿÿÿÿ 1. The ratio a/b is decreasing.
    ÿÿÿÿÿÿÿÿ 2. b has limit.
    ÿÿÿÿÿÿÿÿ 3. a must decrease to below b because of the above reasons.
    ÿÿÿÿÿÿÿÿ 4. Done, n=a+b has limit (cop(n) is known to terminate for n<2?? at
    ÿÿÿÿÿÿÿÿÿÿÿ least).

    ÿÿÿÿÿÿ Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    ÿÿÿÿÿÿ operation is paired with only one even operation, then, at measurement
    ÿÿÿÿÿÿ point A, we have:

    ÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿ a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1
    ÿÿÿÿÿÿ a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿÿ = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿ Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2.
    ÿÿÿÿÿÿÿÿ (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿ may also include --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿ will converge faster than the formula)

    ÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    ÿÿÿÿÿÿ => b = (a+b)/(r+1) = n/(r+1)
    ÿÿÿÿÿÿ After sufficient iterations:
    ÿÿÿÿÿÿ => The limit of r+1 = (n-1)/2 + 1 = (n+1)/2
    ÿÿÿÿÿÿ => b = (2*n)/(n+1) = 2/(1+1/n)
    ÿÿÿÿÿÿ => b = 2 (the limit of b. it is known that n is a large number)

    ÿÿÿÿÿÿ Since b has limit (the numerical value is not important), the iteration
    ÿÿÿÿÿÿ involves an infinite number of iterations of --a, a will inevitably become
    ÿÿÿÿÿÿ zero, so the iteration cannot fail to meet the iteration termination ÿÿÿÿÿÿ condition.
    ----------------------

    1. a/b ratio (formula) is a lower bound estimate as stated. In the real cases,
    ÿÿÿ it decreases faster.
    2. In the iteration, even ops does not change a/b ratio. Ops --a,++b only makes
    ÿÿÿ the ratio a/bÿmore decreasing.
    3. The proof only needs to show there is a limit. What value a/b converges does
    ÿÿÿ not important.

    So we agree a/b converges, but the updates above do not address any of the problems raised in my
    previous post...

    Mike.
    Confirmed, thanks. "b has limit" is flawed.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Mike Terry@3:633/10 to All on Friday, January 30, 2026 04:22:37
    On 30/01/2026 03:03, wij wrote:
    On Fri, 2026-01-30 at 02:20 +0000, Mike Terry wrote:
    On 29/01/2026 21:40, wij wrote:
    On Thu, 2026-01-29 at 16:50 +0000, Mike Terry wrote:
    On 24/01/2026 16:37, wij wrote:
    On Wed, 2025-12-24 at 20:05 +0800, wij wrote:


    I have just finished the script. Any defect,insufficiency, or typo?

    ------------------
    This file is intended a proof of Collatz Conjecture. The contents may be >>>>> updated anytime.
    https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-en.txt/download

    The text is converted by google translate with modest modification from >>>>> https://sourceforge.net/projects/cscall/files/MisFiles/Coll-proof-zh.txt/download
    Reader might want to try different translator or different settings. >>>>>
    -----------------------------------------------------------------------------
    Collatz function ::=

    ÿÿÿÿÿÿÿ int cop(int n) {
    ÿÿÿÿÿÿÿÿÿ if(n<=1) {
    ÿÿÿÿÿÿÿÿÿÿÿ if(n<1) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ throw Error;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ return 1;ÿÿÿÿ // 1 is the iteration endpoint
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿ if(n%2) {
    ÿÿÿÿÿÿÿÿÿÿÿ return 3*n+1; // Odd number rule
    ÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿ return n/2;ÿÿ // Even number rule
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    Collatz number: If an integer n, n?N<1,+1>, after the cop iteration will >>>>> ÿÿÿÿÿ eventually calculate to 1 (i.e., cop(...cop(n))=1), then n is a Collatz
    ÿÿÿÿÿ number. Otherwise n is not a Collatz number.

    Collatz Problem: For each integer n, n?N<1,+1>, is n a Collatz number? IOW,
    ÿÿÿÿÿ the question is equivalent to asking whether the following procedure rcop
    ÿÿÿÿÿ terminates or not.

    ÿÿÿÿÿÿÿ void rcop(int n) {
    ÿÿÿÿÿÿÿÿÿ for(;n!=1;) {
    ÿÿÿÿÿÿÿÿÿÿÿ n=cop(n);
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    Prop: cop(n) iteration contains no cycle (except for the '1-4-2-1' cycle, since
    ÿÿÿÿÿÿ 1 is the termination condition).

    If you could prove just this much, you would become famous, at least amongst mathematicians!

    ÿÿÿ Proof: n can be decomposed into n= a+b. rcop(n) can be rewritten as rcop2(n):

    ÿÿÿÿÿÿÿ void rcop2(int n) {
    ÿÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿÿ for(;a+b!=1;) { // a+b= n in the cop iterative process.
    ÿÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;ÿ // Adjust a and b so that a remains even and the
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // following algorithm can be performed and remains
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ // equivalent to cop(n) iteration.
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) { // Equivalent to (a+b)%2 (because a is even). >>>>> ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;ÿÿÿ // 3*(a+b)+1= (3*a) +(3*b+1)
    ÿÿÿÿÿÿÿÿÿÿÿ } else {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    ÿÿÿÿÿÿÿ Let n?, a?, b? represent the values n,a, and b in the iteration. >>>>> ÿÿÿÿÿÿÿ Assume that the cop(n) iteration is cyclic. The cycle is a fixed-length
    ÿÿÿÿÿÿÿ sequence, and the process must contain the operations 3x+1 and x/2 (and
    ÿÿÿÿÿÿÿ the associated operations --a and ++b, unless n is a 2^x number, but such
    ÿÿÿÿÿÿÿ numbers do not cycle). Let the cyclic sequence of n be:
    ÿÿÿÿÿÿÿÿÿ n?, n?, n?, ..., n? (n=n?).
    ÿÿÿÿÿÿÿ Because --a and ++b are continuously interpolated during the cycle, if

    I think "interpolated" is not the right word.ÿ Not sure exactly what is being claimed, but maybe
    this doesn't matter - check my next comment...

    ÿÿÿÿÿÿÿ a??0, then b? and n?=a?+b? will increase infinitely, contradicting the
    ÿÿÿÿÿÿÿ assumption that n? is cyclic. Therefore, a?=0 must hold during the cycle,

    Regardless of your reasoning, it is clear (and easily proved) that as the cycle repeats, a? at
    the
    same point in the cycle must decrease until it becomes zero.ÿ At this point a? remains zero for
    all
    further i, and no more --a,++b operations occur.ÿ (So there can only be finitely many such ops,
    but
    I agree a? has to become zero, which seems to be what you want to claim.) >>>>

    ÿÿÿÿÿÿÿ but the condition of a?=0 only exists in 1-4-2-1, a?=0 cannot cause the
    ÿÿÿÿÿÿÿ non-1-4-2-1 cycle of n?,n?,n?,...,n?.

    That doesn't follow from anything you've said so far. So this proof will not make you famous. Maybe
    you can work on this and fill in the gap. You need an earlier "Prop: If a?=0 then b? <= 4" or
    equivalent". Then you can be famous!

    It does seem to be the case with numbers I've tried [n up to 30,000,000 ish], that a? only becomes
    zero when we hit the final 1-4-2-1 cycle, so your claim is plausibly /true/, but that's not a
    /proof/ in any sense, of course.


    That doesn't follow from anything you've said so far.ÿ So this proof will not make you famous.
    Maybe
    you can work on this and fill in the gap.ÿ You need an earlier "Prop: If a?=0 then b? <= 4" or
    equivalent".ÿ Then you can be famous!

    It does seem to be the case with numbers I've tried [n up to 30,000,000 ish], that a? only
    becomes
    zero when we hit the final 1-4-2-1 cycle, so your claim is plausibly /true/, but that's not a
    /proof/ in any sense, of course.

    ÿÿÿÿÿÿÿ Therefore, we can conclude that cop(n) iterations are non-cyclic.

    No, this doesn't follow because your 1-4-2-1 cycle claim is not proved.


    Prop: For any n?N<1,+1>, the cop iteration operation terminates.
    ÿÿÿ Proof: Since an odd number n will always become even immediately after the
    ÿÿÿÿÿÿÿ cop iteration, it must undergo n/2 iterations. Therefore, we have an
    ÿÿÿÿÿÿÿ equivalent rcop3:

    ÿÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ // a/b measure point A
    ÿÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿ }

    ÿÿÿÿÿÿÿ Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    ÿÿÿÿÿÿÿ operation is paired with only one even operation (the actual ratio is 1.5
    ÿÿÿÿÿÿÿ even operations, but 1.5 is a statistical value; the decisive inference
    ÿÿÿÿÿÿÿ can only take the guaranteed value of 1). Then, at measurement point A,
    ÿÿÿÿÿÿÿ we have:

    ÿÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿÿ a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    This is just an approximation, not exact.ÿ It is not hard to get the exact value, since you seem
    to
    know about geometric series...

    ÿÿÿÿÿÿÿ a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿÿÿ = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿÿ Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2.

    I agree with this value (n-1)/2, /given your assumptions/ :
    -ÿÿ n odd
    -ÿÿ no --a operations
    -ÿÿ every odd op is followed by exactly one even op.

    But those assumptions are impossible in a real example, and real sequences will include multiple
    even ops and/or --a ops.

    OTOH all sequences have a?/b? as non-increasing, so a?/b? will reach zero (and stay there) or
    converge to some other limit value >= 0.ÿ In the latter case, you have not shown that that limit
    value will be (n-1)/2.ÿ (Hopefully your argument below does not depend on the particular value
    to
    which it converges?)

    ÿÿÿÿÿÿÿÿÿ (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿÿ may also include --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿÿ will converge faster than the formula)

    It must converge, but not necessarily to (n-1)/2 ...

    After this point your argument seems to lose focus, and the notation is wrong!


    ÿÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    ÿÿÿÿÿÿÿ => b = (a+b)/(r+1)

    ok this is simple algebra for any /specific/ iteration value of n,a,b.ÿ These values are
    changing as
    we iterate...

    ÿÿÿÿÿÿÿ Assuming the cop(n) iteration does not terminate, and m is one of the
    ÿÿÿÿÿÿÿ number in the iteration sequence. Therefore, we can derive the >>>>> ÿÿÿÿÿÿÿ following:
    ÿÿÿÿÿÿÿ => b = m/(r+1)

    True for m,b,r for /that specific iteration/.

    ÿÿÿÿÿÿÿ => The limit of r+1 = (m-1)/2 + 1 = (m+1)/2
    ÿÿÿÿÿÿÿ => b = (2*m)/(m+1) = 2/(1+1/m)
    ÿÿÿÿÿÿÿ => b = 2 (the limit of b. At least it is known that m will be a large
    ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ number)

    No that's not right - you're mixing values of m,b,r with those for later iterations of cop() and
    with limits.ÿ Also you're assuming r-->(m-1)/2.ÿ That was a specific result given your
    (impossible)
    assumptions listed above.ÿ In general r /does/ converge, but might converge to some other
    number, or
    become zero (in which case it also converges to zero so it's still true r converges).ÿ That is,
    unless you find a way to fix your proof to prove otherwise...

    To avoid confusing m,b,r as you've defined them with later iterations of cop(), best to call the
    values for later iterations m?,b?,r? or similar.ÿ And assume r?-->R (e.g.).

    So:
    ÿÿÿÿ The limit of r+1 = R+1ÿÿÿÿÿÿ // with possibility R=0
    ÿÿÿÿ b? = m?/(r?+1)
    ÿÿÿÿ lim b? = lim m? / (R+1)
    ... EXCEPT that you have not shown that m? converges, so that last line is nonsense - we only
    use
    'lim' symbol when we the limits are known to exist...


    ÿÿÿÿÿÿÿ Since there is a limit (the numerical value is not important), >>>>
    ??? a limit to what?ÿ r? ---> R, but it seems you're trying to argue b? converges?ÿ That's not
    plausible.ÿ You can see this must be wrong, just from your earlier (overly) simplified sequence
    for
    which you originally calculated R = (n-1)/2. In that calculation you wrote:

    ÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    and it is clear that b? is growing in an unbounded fashionry, not converging to b=2.ÿ You've
    just
    got muddled...ÿ Note: I don't necessarily agree with this b? formula - it looks to be only an
    approximation, but I do agree with your a?/b? limit [with your given assumptions].

    ÿÿÿÿÿÿÿ the
    ÿÿÿÿÿÿÿ iteration involves an infinite number of iterations of --a, a will
    ÿÿÿÿÿÿÿ inevitably become zero, so the iteration cannot fail to meet the >>>>> ÿÿÿÿÿÿÿ iteration termination contion.

    That is also not right - once a? becomes zero, there will be /no more --a operations, so there
    can't
    be infinitely many of them!

    Regardless:

    1.ÿ IF there are infinitely many iterations of --a, they can be interspersed
    ÿÿÿÿÿ with a *= 3 operations, so it does not follow (just from what you've said)
    ÿÿÿÿÿ that a /must/ become zero.
    2.ÿ If a does become zero, it does not follow that the 1-4-2-1 loop has been
    ÿÿÿÿÿ encountered, unless you have some argument to prove that.ÿ [This is >>>> ÿÿÿÿÿ the same problem as with your earlier "no cycles" proof.]


    ÿÿÿÿÿÿÿ If n is even, then repeating the even operation (a finite number of times)
    ÿÿÿÿÿÿÿ cop(n) will yield an odd number without affecting the termination result
    ÿÿÿÿÿÿÿ as stated above. Therefore, the proposition is proved.

    ..aside from fixing the problems above.


    Mike.

    I agree with many point of your criticism, it is helpful.
    Since your comments are on the original script, I will post the updated version to avoid
    unnecessary reply.

    --- [quote from the finalized version]
    Prop:ÿÿ ....[cut]
    ÿÿÿÿÿÿ void rcop3(int n) {
    ÿÿÿÿÿÿÿÿ int a=n,b=0;
    ÿÿÿÿÿÿÿÿ for(; a+b!=1;) {
    ÿÿÿÿÿÿÿÿÿÿ if((a%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ --a; ++b;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ // a/b measure point A
    ÿÿÿÿÿÿÿÿÿÿ if((b%2)!=0) {
    ÿÿÿÿÿÿÿÿÿÿÿÿ a= 3*a;
    ÿÿÿÿÿÿÿÿÿÿÿÿ b= 3*b+1;
    ÿÿÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿÿÿÿÿ a= a/2;
    ÿÿÿÿÿÿÿÿÿÿ b= b/2;
    ÿÿÿÿÿÿÿÿ }
    ÿÿÿÿÿÿ }

    ÿÿÿÿÿÿ The following proof demonstrates:
    ÿÿÿÿÿÿÿÿ 1. The ratio a/b is decreasing.

    Agree.

    ÿÿÿÿÿÿÿÿ 2. b has limit.

    Not proven.

    ÿÿÿÿÿÿÿÿ 3. a must decrease to below b because of the above reasons.

    Not proven.

    ÿÿÿÿÿÿÿÿ 4. Done, n=a+b has limit (cop(n) is known to terminate for n<2?? at
    ÿÿÿÿÿÿÿÿÿÿÿ least).

    ÿÿÿÿÿÿ Let n be odd and there be no `--a`, `++b` process. Assume that each odd
    ÿÿÿÿÿÿ operation is paired with only one even operation, then, at measurement
    ÿÿÿÿÿÿ point A, we have:

    ÿÿÿÿÿÿ a? = n-1
    ÿÿÿÿÿÿ a? = (3*a???)/2 = ... = (n-1)*(3/2)???
    ÿÿÿÿÿÿ b? = 1
    ÿÿÿÿÿÿ b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1
    ÿÿÿÿÿÿ a?/b? = (a???)/(b???) = ((n-1)*(3/2)???)/(2*(3/2)??? -1)
    ÿÿÿÿÿÿÿÿÿÿÿÿ = ... = (n-1)/(2-1/(3/2)???)

    ÿÿÿÿÿÿ Interim summary: a?/b? < a???/b??? and lim{x->ì} a?/b? = (n-1)/2. >>> ÿÿÿÿÿÿÿÿ (After eight iterations, a?/b? is approximately 0.51. Actual iterations
    ÿÿÿÿÿÿÿÿÿ may also include --a and ++b operations, so the actual value of a?/b?
    ÿÿÿÿÿÿÿÿÿ will converge faster than the formula)

    It must converge, but not necessarily to (n-1)/2 ...

    After this point your argument seems to lose focus, and the notation is wrong!


    ÿÿÿÿÿÿ Let r = a/b, then n/b = (a+b)/b = a/b+1 = r+1
    ÿÿÿÿÿÿ => b = (a+b)/(r+1) = n/(r+1)

    ok this is simple algebra for any /specific/ iteration value of n,a,b. These values are changing as
    we iterate...

    ÿÿÿÿÿÿ After sufficient iterations:
    ÿÿÿÿÿÿ => The limit of r+1 = (n-1)/2 + 1 = (n+1)/2

    you have not shown r converges to (n-1)/2, only that it converges to /something/.
    [You showed it converges to (n-1)/2 under your stated conditions which do not apply in general.

    ÿÿÿÿÿÿ => b = (2*n)/(n+1) = 2/(1+1/n)

    No that's not right - you're mixing values of m,b,r with those for later iterations of cop() and
    with limits. Also you're assuming r-->(n-1)/2. That was a specific result given your (impossible)
    assumptions listed above. In general r /does/ converge, but might converge to some other number, or
    become zero (in which case it also converges to zero so it's still true r converges). That is,
    unless you find a way to fix your proof to prove otherwise...

    Let's say r? ---> R. So:

    b? = n?/(r?+1)
    lim b? = lim n? / (R+1) // r?+1 ---> R+1
    ... EXCEPT that *you have not shown that n? converges*, so that last line is nonsense - we only use
    'lim' symbol when we the limits are known to exist...

    ÿÿÿÿÿÿ => b = 2 (the limit of b. it is known that n is a large number)

    You have not proved that b converges. You can see this must be wrong, just from your earlier
    (overly) simplified sequence for which you originally calculated R = (n-1)/2. In that calculation
    you wrote:

    b? = (3*b???+1)/2 = ... = 2*(3/2)??? -1

    and it is clear that b? is growing in an unbounded fashionry, not converging to b=2. You've just
    got muddled... Note: I don't necessarily agree with this b? formula - it looks to be only an
    approximation, but I do agree with your a?/b? limit [with your given assumptions].


    ÿÿÿÿÿÿ Since b has limit (the numerical value is not important), the iteration
    ÿÿÿÿÿÿ involves an infinite number of iterations of --a, a will inevitably become
    ÿÿÿÿÿÿ zero, so the iteration cannot fail to meet the iteration termination
    ÿÿÿÿÿÿ condition.

    That is also not right - once a? becomes zero, there will be /no more --a operations, so there can't
    be infinitely many of them!

    Regardless:

    1. IF there are infinitely many iterations of --a, they can be interspersed
    with a *= 3 operations, so it does not follow (just from what you've said)
    that a /must/ become zero.
    2. If a does become zero, it does not follow that the 1-4-2-1 loop has been
    encountered, unless you have some argument to prove that. [This is
    the same problem as with your earlier "no cycles" proof.]

    ----------------------

    1. a/b ratio (formula) is a lower bound estimate as stated. In the real cases,
    ÿÿÿ it decreases faster.
    2. In the iteration, even ops does not change a/b ratio. Ops --a,++b only makes
    ÿÿÿ the ratio a/bÿmore decreasing.
    3. The proof only needs to show there is a limit. What value a/b converges does
    ÿÿÿ not important.

    So we agree a/b converges, but the updates above do not address any of the problems raised in my
    previous post...

    Mike.

    Will you elaborate precisely?

    Original comments repeated above.


    Mike.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Keith Thompson@3:633/10 to All on Thursday, January 29, 2026 20:38:19
    wij <wyniijj5@gmail.com> writes:
    [329 lines deleted]

    Just a gentle reminder that this discussion, though it occasionally
    includes something that looks like C code, is not about C.

    There's a related thread about the Collatz Conjecture in comp.theory.
    I encourage anyone who feels the need to discuss it to do so there --
    or at least not to do so here.

    --
    Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
    void Void(void) { Void(); } /* The recursive call of the void */

    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Janis Papanagnou@3:633/10 to All on Friday, January 30, 2026 06:33:47
    On 2026-01-28 21:59, Chris M. Thomasson wrote:
    [...]

    A real with infinite precision can hold an irrational?

    What are you talking about here? Abstract computers? - Please
    explain.[*]

    I had been talking about a geometric representation of mathematics
    by the ancient Greeks. In that case an "irrational" was represented
    by a geometric entity, e.g. the diagonal of a square (for sqrt(2)).

    I'm not aware that back then they used real numbers with precision.

    Janis

    [*] OTOH, this all - including the OP - appears to be quite OT and
    IMO better fits in a math newsgroup, so we can also just abstain
    from further digressions.


    --- PyGate Linux v1.5.6
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Chris M. Thomasson@3:633/10 to All on Friday, January 30, 2026 11:59:06
    On 1/29/2026 9:33 PM, Janis Papanagnou wrote:
    On 2026-01-28 21:59, Chris M. Thomasson wrote:
    [...]

    A real with infinite precision can hold an irrational?

    What are you talking about here? Abstract computers? - Please
    explain.[*]

    Its an abstract thought indeed... :^)


    I had been talking about a geometric representation of mathematics
    by the ancient Greeks. In that case an "irrational" was represented
    by a geometric entity, e.g. the diagonal of a square (for sqrt(2)).

    I'm not aware that back then they used real numbers with precision.

    Think of a number where each, say 10-ary symbols 0...9, is derived from
    a TRNG. For an unsigned integer, say the _first_ symbol is a TRNG from
    1...9. All the others are TRNG from 0...9.

    401986393421051...

    Take it to infinity... is it a number???

    ;^)


    Janis

    [*] OTOH, this all - including the OP - appears to be quite OT and
    IMO better fits in a math newsgroup, so we can also just abstain
    from further digressions.


    Well, shit happens... ;^)

    --- PyGate Linux v1.5.8
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From wij@3:633/10 to All on Saturday, January 31, 2026 05:30:10
    On Thu, 2026-01-29 at 20:38 -0800, Keith Thompson wrote:
    wij <wyniijj5@gmail.com> writes:
    [329 lines deleted]

    Just a gentle reminder that this discussion, though it occasionally
    includes something that looks like C code, is not about C.

    Depend on readers understanding.

    There's a related thread about the Collatz Conjecture in comp.theory.
    I encourage anyone who feels the need to discuss it to do so there --
    or at least not to do so here.

    Agree.

    When cases involve whether 'for/while' is better, or wheher indent-2/3/8

    should the standard -> preference issues are on topic.
    When cases involve math/logic -> off topic.

    I am talking about string processing(on-topic?), math/logic is not the faul
    t.
    Whatever you do will end up to logic to be decidable.

    https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/d ownload
    ...
    Axiom 1: Natural numbers are discrete symbols of finite length with a finit
    e
    number of counting steps.
    Axiom 2: An object (e.g., number, form) and its (operational) properties ex
    ist
    simultaneously through definition.

    All are manipulations of string. Axiom 2 is stated in terms of OO (object)
    .
    Of course, understanding is another matter.


    --- PyGate Linux v1.5.8
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)
  • From Jan van den Broek@3:633/10 to All on Saturday, January 31, 2026 14:11:20
    I'm not intendig to proof anything, but I wrote this some time ago when being bored.

    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    #include <assert.h>
    #include <ctype.h>

    #define N 1024

    int check(char *s)
    {
    int result=1;
    while (*s)
    {
    if (!isdigit(*s++))
    {
    result=0;
    }
    }
    return(result);
    }

    char *insert(char *s,char c,int *l)
    {
    int i;
    assert (*l<(N-1));

    for (i=*l; i; --i)
    {
    s[i]=s[i-1];
    }
    s[0]=c;
    ++(*l);
    s[*l]='\0';
    return(s);
    }

    char *even(char *s,int *l)
    {
    int c,carry,i;
    char *copy;

    copy=malloc(*l+1);
    assert(copy!=NULL);
    copy[*l]='\0';
    carry=0;
    for (i=0; i<*l; ++i)
    {
    c=s[i]-'0'+carry;
    carry=0;
    if (c&1)
    {
    carry=10;
    c-=1;
    }
    c=c/2;
    copy[i]=c+'0';
    }
    i=0;
    while (copy[i]=='0')
    {
    ++i;
    }
    (*l)-=i;
    strcpy(s,copy+i);
    free(copy);
    return(s);
    }

    char *odd(char *s,int *l)
    {
    int c,carry,i;
    char *copy;

    copy=malloc(*l+2);
    assert(copy!=NULL);
    carry=0;
    copy[*l]='\0';
    for (i=*l; i; --i)
    {
    c=3*(s[i-1]-'0')+carry;
    if (i==*l)
    {
    ++c;
    }
    copy[i-1]=(c%10)+'0';
    carry=(c-(c%10))/10;
    }
    while(carry)
    {
    c=carry%10;
    insert(copy,c+'0',l);
    carry=(c-(c%10))/10;
    }
    strcpy(s,copy);
    free(copy);
    return(s);
    }

    int main(int argc,char *argv[])
    {
    int i,l;
    char data[N];

    for (i=1; i<argc; ++i)
    {
    strcpy(data,argv[i]);
    if (check(data))
    {
    puts(data);
    l=strlen(data);
    while (strcmp(data,"1"))
    {
    if (data[l-1]&1)
    {
    odd(data,&l);
    }
    else
    {
    even(data,&l);
    }
    puts(data);
    }
    }
    }
    }
    --
    A tuna is a way of Liff

    Jan v/d Broek
    balglaas@xs4all.nl

    --- PyGate Linux v1.5.8
    * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)