Re: HP proofs appear to be peer reviewed garbage

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olcott

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Jul 29, 2021, 5:04:52 PMJul 29
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On 7/29/2021 3:46 PM, dklei...@gmail.com wrote:
> On Thursday, July 29, 2021 at 1:01:49 PM UTC-7, olcott wrote:
>> On 7/29/2021 2:50 PM, Mr Flibble wrote:
>>> On Thu, 29 Jul 2021 13:08:47 -0500
>>> olcott <No...@NoWhere.com> wrote:
>>>
>>>> On 7/29/2021 12:58 PM, Mr Flibble wrote:
>>>>> The extant HP proofs appear to be peer reviewed garbage suggesting
>>>>> the state of the art is one big echo chamber with an amazing lack of
>>>>> insight.
>>>>>
>>>>> Something predicated on an erroneous contradiction is itself
>>>>> erroneous.
>>>>>
>> I take back my prior comment, (shown below) the above sentence provides
>> the key essence of support for the first sentence.
>>>>> This is a troll.
>>>>>
>>>>> /Flibble
>>>>>
>>>>
>>>> This post is a troll on the basis that it is a mere empty assertion
>>>> entirely bereft of any supporting reasoning.
>>>
>>> Oh, so you have changed your tune and you now agree with the great
>>> atheist Christopher Hitchens that assertions made without evidence can
>>> be dismissed without evidence. This is progress indeed.
>>>
>>> This is a troll.
>>>
> I am a mathematician and old enough that I took a few courses from
> Tarski before I decided I liked Banach Spaces better. I have been
> watching this years-long argument and admiring it as a horrible
> example. PO is sui generis it's you other guys I am amazed at. Why
> do you tolerate him?
>
> I gag completely at PO's attempt to make Turing machines a C
> language subject. At the very least you should make him define
> the mapping behind his "equivalence".
>
> But there are other sloppy points you have let him have his own
> way with. For example; suppose T is a Turing Machine what does
> H(T) mean technically if H is a Turing Machine alleged to be a halt
> decider? I am willing to accept a quintuple (or whatever) as a
> definition of a Turing Machine.
>
> From where I sit a Turing Machine is a quadruple of a Turing Data Space,
> a Turing Code Space, a Focus and a Halt Set where: A Turing Data Space
> is a triple of two stacks called Left and Right and a singleton called
> Center. The set of things in Left, Center and Right is the Alphabet. There
> is a set called State Names. The value of Focus is a Sate Name. The Halt
> Set is a set of state names. A Turing Code Space is a function from State
> Names to functions from the Alphabet to Commands. A Command is a
> triple of a Character from the Alphabet, a Boolean called Left-or-Right
> and a State Name. The Focus is the name of the starting state. If any of
> the Halting Set becomes the Focus execution of the machine stops.
>
> That's a bit complicated. I hope I got it right.
>
> I could go on but nobody wants me to.
>

I very distinguished scholar already made the same sort of
simplification that I made in the language that he invented that was an
ancestor to C: CPL. Flibble's insight is based on this Strachey
simplification:

Here are Strachey's (verbatim) own words
Suppose T[R] is a Boolean function taking a routine
(or program) R with no formal or free variables as its
argument and that for all R, T[R] — True if R terminates
if run and that T[R] = False if R does not terminate.
Consider the routine P defined as follows

rec routine P
§L:if T[P] go to L
Return §

If T[P] = True the routine P will loop, and it will
only terminate if T[P] = False. In each case T[P] has
exactly the wrong value, and this contradiction shows
that the function T cannot exist.

Strachey, C 1965. An impossible program The Computer Journal, Volume 7,
Issue 4, January 1965, Page 313, https://doi.org/10.1093/comjnl/7.4.313

// Strachey CPL translated to C
void P()
{
if (H((u32)P))
HERE: goto HERE;
}



--
Copyright 2021 Pete Olcott

"Great spirits have always encountered violent opposition from mediocre
minds." Einstein

olcott

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Jul 29, 2021, 5:06:25 PMJul 29
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A very distinguished scholar already made the same sort of

olcott

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Jul 29, 2021, 5:28:25 PMJul 29
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On 7/29/2021 4:14 PM, André G. Isaak wrote:
> On 2021-07-29 15:04, olcott wrote:
>
>> I very distinguished scholar already made the same sort of
>> simplification that I made in the language that he invented that was
>> an ancestor to C: CPL. Flibble's insight is based on this Strachey
>> simplification:
>
> Nowhere does Strachey refer to his CPL program as a 'Turing Machine'.
>
> André

No instead he simply cuts to the chase and says that his short proof
sums up the one by Turing:

the proof ... is so short and simple that it
may be of interest to casual readers. The version
below uses CPL, but not in any essential way.

Sir,
A well-known piece of folk-lore among programmers
holds that it is impossible to write a program which can
examine any other program and tell, in every case, if it
will terminate or get into a closed loop when it is run. I have never
actually seen a proof of this in print, and
though Alan Turing once gave me a verbal proof (in a
railway carriage on the way to a Conference at the
NPL in 1953), I unfortunately and promptly forgot the
details. This left me with an uneasy feeling that the
proof must be long or complicated, but in fact it is so
short and simple that it may be of interest to casual
readers. The version below uses CPL, but not in any
essential way.
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