Sujet : Re: DDD correctly emulated by H0 -- Ben agrees that Sipser approved criteria is met
De : mikko.levanto (at) *nospam* iki.fi (Mikko)
Groupes : comp.theoryDate : 28. Jun 2024, 10:30:34
Autres entêtes
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On 2024-06-27 16:56:56 +0000, olcott said:
On 6/27/2024 10:35 AM, Mikko wrote:
On 2024-06-27 14:10:02 +0000, olcott said:
On 6/27/2024 2:36 AM, Mikko wrote:
On 2024-06-26 12:58:59 +0000, olcott said:
On 6/26/2024 3:41 AM, Mikko wrote:
On 2024-06-26 02:29:59 +0000, olcott said:
On 6/25/2024 9:23 PM, Richard Damon wrote:
On 6/25/24 10:05 PM, olcott wrote:
On 6/25/2024 8:47 PM, Richard Damon wrote:
On 6/25/24 1:45 PM, olcott wrote:
On 6/25/2024 9:46 AM, Alan Mackenzie wrote:
Hi, Ben.
Ben Bacarisse <ben@bsb.me.uk> wrote:
Alan Mackenzie <acm@muc.de> writes:
In comp.theory olcott <polcott333@gmail.com> wrote:
On 6/25/2024 4:22 AM, joes wrote:
Am Sat, 22 Jun 2024 13:47:24 -0500 schrieb olcott:
On 6/22/2024 1:39 PM, Fred. Zwarts wrote:
Op 21.jun.2024 om 15:21 schreef olcott:
When we stipulate that the only measure of a correct emulation is the
semantics of the x86 programming language then we see that when DDD is
correctly emulated by H0 that its call to H0(DDD) cannot possibly
return.
Yes. Which is wrong, because H0 should terminate.
[ .... ]
The call from DDD to H0(DDD) when DDD is correctly emulated
by H0 cannot possibly return.
Until you acknowledge this is true, this is the
only thing that I am willing to talk to you about.
I think you are talking at cross purposes. Joes's point is that H0
should terminate because it's a decider. You're saying that when H0 is
"correctly" emulating, it won't terminate. I don't recall seeing anybody
arguing against that.
So you're saying, in effect, H0 is not a decider. I don't think anybody
else would argue against that, either.
He's been making exactly the same nonsense argument for years. It
became crystal clear a little over three years ago when he made the
mistake of posting the pseudo-code for H -- a step by step simulator
that stopped simulating (famously on line 15) when some pattern was
detected. He declared false (not halting) to be the correct result for
the halting computation H(H_Hat(), H_Hat()) because of what H(H_Hat(),
H_Hat()) would do "if line 15 were commented out"!
PO does occasionally make it clear what the shell game is.
I think it's important for (relative) newcomers to the newsgroup to
become aware of this. Each one of them is trying to help PO improve his
level of learning. They will eventually give up, as you and I have
done, recognising (as Mike Terry, in particular, has done) that
enriching PO's intellect is a quite impossible task.
What's the betting he'll respond to this post with his usual short
sequence of x86 assembly code together with a demand to recognise
something or other as non-terminating?
--
Ben.
<MIT Professor Sipser agreed to ONLY these verbatim words 10/13/2022>
If simulating halt decider H correctly simulates its input D
until H correctly determines that its simulated D would never
stop running unless aborted then
H can abort its simulation of D and correctly report that D
specifies a non-halting sequence of configurations.
</MIT Professor Sipser agreed to ONLY these verbatim words 10/13/2022>
On 10/14/2022 7:44 PM, Ben Bacarisse wrote:
> I don't think that is the shell game. PO really /has/ an H
> (it's trivial to do for this one case) that correctly determines
> that P(P) *would* never stop running *unless* aborted.
>
> He knows and accepts that P(P) actually does stop. The
> wrong answer is justified by what would happen if H
> (and hence a different P) where not what they actually are.
>
Ben thinks that I tricked professor Sipser into agreeing
with something that he did not fully understand.
*The real issue is that no one here sufficiently understands*
*the highlighted portion of the following definition*
Computable functions are the formalized analogue of the
intuitive notion of algorithms, in the sense that a
function is computable if there exists an algorithm
that can do the job of the function, i.e.
*given an input of the function domain*
*it can return the corresponding output*
https://en.wikipedia.org/wiki/Computable_function
But only if the function is, in fact, computable.
Since Halting isn't, you can't use that fact.
If I ask you: What time is it?
and you do not tell me the answer to the question hidden
in my mind "What did you have for dinner?" We cannot say
that you provided the wrong answer when you tell me what
time it is.
Because I answered the actual question.
Just like the "Halt Decider" needs to answer the "Halt Decider Question" and not answer about POOP.
When we ask H to tell us whether its actual input halts
H can only answer that P correctly simulated by H will not halt.
H cannot answer the question hidden in your mind.
Then you are just admitting that it can't be a Halt Decider.
If it isn't what the definition requires, it just isn't one.
Yes and everyone knows that computer scientists are much
more infallible than God thus cannot possibly ever make
a definition that is incoherent in ways that these 100%
infallible computer scientists never noticed.
Actually, it is the opposite. Everybody, or at least all computer
scientists and engineers, know that they, and all peaple, are fallible,
at least when making programs and when inferring about programs. Therefore
computer engineers demand that every program must be tested, and computer
scinetists demand that every claim is proven.
If this was true then everyone here would already know
that H(P,P) is not even being asked about the behavior
of the directly executed P(P).
Everyone knwos that H(P,P) is not asked anything.
In computability theory and computational complexity theory, a
decision problem is a computational problem that can be posed as
a yes–no question of the input values.
https://en.wikipedia.org/wiki/Decision_problem
That's right. But that question cannot be presented to the decider.
Only the input values can.
In other words you are saying that Turing machines do not
typically understand English.
I didn't mean it that generally, only about deciders, but yes, typical
Turing machines do not understand any English. More specifically, the
specification of a halt decider (or any typical decider) prevents it
from being asked in any language.
None-the-less no-one here understands that every halt decider
is only required to report on the behavior that its actual
input actually maps to.
As far as I have seen, most of them do. And not just maps but maps
in the way specified by the problem statement.
Instead everyone here expects that the halt decider must map
to the English description of what the authors of textbooks
expect it to map to.
Your "everyone" is a lie. As far as I have seen, nobody has expressed
that expectation, and several have said otherwise.
We already agreed that Turing machines do not typically
understand English, so this assumption is stupid.
You may have agreed but you failed to keep that agreement.
*DDD correctly simulated by H0 DOES NOT HALT*
The message where DDD was introduced specifies that DDD halts
if and only if H0 halts.
Everyone here stupidly ignores that the pathological
relationship that DDD calls H0(DDD) changes the behavior
of DDD.
If and only if it changes the behaviour of H0, which is possible if
and only if H0 is not a pure function.
-- Mikko