Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C]

From	Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups	comp.theory, comp.lang.c
Subject	Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C]
Followup-To	comp.theory
Date	2020-08-31 03:53 +0100
Organization	A noiseless patient Spider
Message-ID	<87d037r0e8.fsf@bsb.me.uk> (permalink)
References	(1 earlier) <20200830120314.347@kylheku.com> <87eennswge.fsf@bsb.me.uk> <wr2dnaioYPFtitHCnZ2dnUU7-UXNnZ2d@giganews.com> <87o8mrr48v.fsf@bsb.me.uk> <r4qdnWZZQdZl_NHCnZ2dnUU7-S3NnZ2d@giganews.com>

Cross-posted to 2 groups.

Followups directed to: comp.theory

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olcott <NoOne@NoWhere.com> writes:

> On 8/30/2020 8:30 PM, Ben Bacarisse wrote:
>> olcott <NoOne@NoWhere.com> writes:
>>
>
>>>>> I had a discussion with this with someone who convinced me of the
>>>>> following: in C we can allocate automatic storage (informally,
>>>>> "local variables on the stack") via recursion. If we do this without
>>>>> taking the address of anything, then pointers do not appear in
>>>>> the program, and thus, in the abstract sense, we don't run into the
>>>>> issue of pointers being of finite width.  With that restriction, we have
>>>>> no random access (the program cannot access material in existing
>>>>> activation frames without returning to them).  Therefore what we have is
>>>>> a push-down automaton (PDA).  A PDA is strictly less powerful than a
>>>>> Turing machine. It contains an infinity in that it can push down as far
>>>>> as it needs to, but there are some computations that can't be carried
>>>>> out with a universal push down machine.
>>>>
>>>> Hmm...  Modern C has threads and therefore more than one stack.  A PDA
>>>> with two stacks is Turing complete so there may be a way after all.
>>>> Nice one!
>>>
>>> There you go teamwork. Between you and Kaz.
>>
>> Note "may".  In the end it is likely to come down to how one chooses to
>> interpret the standard.  It's really not a clear-cut question.  (See my
>> reply to Mike Terry about that.)
>
> On 8/30/2020 6:23 PM, Mike Terry wrote:
>> On 30/08/2020 21:36, Ben Bacarisse wrote:
>>> There is, though, another way to argue about C.  Implement
>>> your UTM in our all-too-finite C as, say, compiled by gcc.
>>> If a computation fails
>>> for lack of space, just get the gcc people to double the size
>>> of all the pointers and try again.  Repeat as necessary,
>>> using pointers simulated in software.  Each iteration can
>>> conform to the C standard, and since you only need to be able
>>> to run terminating computations to be Turing complete, one can
>>> show that there is (in theory) a C implementation that
>>> can run any given computation.
>>
>> Yes, for a given terminating calculation.  But to do this we just
>> declare a big enough array to run the calculation, and run it.  This
>> doesn't take too much thought or discussion regarding either program
>> design or language considerations,

You are not quoting the reply I was referring to.  Obviously I was
talking about my reply about there only ever being a finite number of
objects with automatic storage duration.

> So Kaz spurred an idea in you that spurred an idea in Mike that seems
> to complete the circle.

No, you are mixing up what the remarks are about.

> The input to the halt decider is the x86 machine language of itself.

Halting for x86 code is decidable.

You should pick a Turing complete notation and use that as the input to
a decider.  Why on Earth are you not doing so?  There are dozens of very
simple ones to choose from, including the probably the simplest pf all:
a notation for Turing machines themselves.

-- 
Ben.

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Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 13:55 -0500
  Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Kaz Kylheku <793-849-0957@kylheku.com> - 2020-08-30 19:19 +0000
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 14:40 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 14:57 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 15:02 -0500
      Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-30 22:05 +0100
        Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 17:01 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 15:59 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 16:19 -0500
      Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-31 02:30 +0100
        Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 21:35 -0500
          Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-31 03:53 +0100
            Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] R Kym Horsell <kym@kymhorsell.com> - 2020-08-31 03:24 +0000
              Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-31 14:51 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] R Kym Horsell <kym@kymhorsell.com> - 2020-08-31 14:06 +0000
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 10:08 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-31 21:12 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] R Kym Horsell <kym@kymhorsell.com> - 2020-08-31 21:39 +0000
            Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 01:06 -0500
          Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-08-30 23:55 -0500
            Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-31 14:28 +0100
              Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-08-31 08:34 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-01 01:40 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-08-31 23:47 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-01 11:17 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-01 08:30 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-01 15:48 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-01 10:33 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-02 02:10 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-01 20:38 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-02 03:32 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-01 21:51 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-02 04:15 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-01 22:43 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] André G. Isaak <agisaak@gm.invalid> - 2020-09-01 22:48 -0600
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-02 00:17 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] André G. Isaak <agisaak@gm.invalid> - 2020-09-01 23:34 -0600
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-02 00:42 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] André G. Isaak <agisaak@gm.invalid> - 2020-09-03 05:57 -0600
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-03 09:21 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] André G. Isaak <agisaak@gm.invalid> - 2020-09-03 12:05 -0600
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-03 16:39 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-09-02 00:29 -0500
              Re: Transforming "C" into a Turing equivalent language 001 [x86 based halt decider] olcott <NoOne@NoWhere.com> - 2020-08-31 14:01 -0500
          Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Andy Walker <anw@cuboid.co.uk> - 2020-08-31 10:05 +0100
            Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 08:49 -0500
              Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Andy Walker <anw@cuboid.co.uk> - 2020-08-31 17:37 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Jeff Barnett <jbb@notatt.com> - 2020-08-31 11:20 -0600
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Andy Walker <anw@cuboid.co.uk> - 2020-08-31 19:01 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 13:11 -0500
                Floating point [was Re: Transforming "C" ...] Andy Walker <anw@cuboid.co.uk> - 2020-09-01 11:55 +0100
                Re: Floating point [was Re: Transforming "C" ...] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-01 15:35 +0100
                Re: Floating point Andy Walker <anw@cuboid.co.uk> - 2020-09-01 20:16 +0100
                Re: Floating point Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-02 01:17 +0100
                Re: Floating point Andy Walker <anw@cuboid.co.uk> - 2020-09-02 01:44 +0100
                Re: Floating point Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-02 02:20 +0100
                Re: Floating point Andy Walker <anw@cuboid.co.uk> - 2020-09-02 12:14 +0100
                Re: Transforming "C" into a Turing equivalent language 002 [Translating C to a unary TM] olcott <NoOne@NoWhere.com> - 2020-08-31 13:10 -0500
                Transforming "C" into a Turing equivalent language 002 [Translating C to a unary TM] olcott <NoOne@NoWhere.com> - 2020-08-31 13:00 -0500
                Re: Transforming "C" into a Turing equivalent language 004 [x86 language mapped to unlimited integers] olcott <NoOne@NoWhere.com> - 2020-09-02 11:44 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-30 20:35 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 09:59 -0500
      Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-31 19:33 +0100
        Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 13:51 -0500
        Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Jeff Barnett <jbb@notatt.com> - 2020-08-31 15:33 -0600
          Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 16:43 -0500
            Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Jeff Barnett <jbb@notatt.com> - 2020-08-31 19:09 -0600
              Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 20:18 -0500
          Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-08-31 23:51 +0100
            Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 18:25 -0500
              Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Jeff Barnett <jbb@notatt.com> - 2020-08-31 19:13 -0600
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 20:17 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Jeff Barnett <jbb@notatt.com> - 2020-08-31 22:51 -0600
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-01 00:18 -0500
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Jeff Barnett <jbb@notatt.com> - 2020-09-01 00:02 -0600
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 14:28 -0500
      Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2020-08-31 22:51 +0100
        Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 17:49 -0500
          Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2020-09-01 02:42 +0100
            Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 23:30 -0500
              Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2020-09-01 15:30 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-01 09:51 -0500
            Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 23:32 -0500
              Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2020-09-01 16:15 +0100
                Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-01 10:53 -0500
        Re: Transforming "C" into a Turing equivalent language 001 [x86_UTM trace] olcott <NoOne@NoWhere.com> - 2020-08-31 23:24 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-08-31 15:05 -0500
    Re: Transforming "C" into a Turing equivalent language 002 [HP proof refutation] olcott <NoOne@NoWhere.com> - 2020-09-01 17:00 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-01 17:46 -0500
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-01 18:58 -0500
      Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-02 02:37 +0100
        Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-01 20:40 -0500
          Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-02 03:24 +0100
    Re: Transforming "C" into a Turing equivalent language 005 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-02 11:20 -0500
      Re: Transforming "C" into a Turing equivalent language 005 [Providing unlimited memory access to C] Kaz Kylheku <793-849-0957@kylheku.com> - 2020-09-02 17:22 +0000
        Re: Transforming "C" into a Turing equivalent language 005 [Providing unlimited memory access to C] olcott <NoOne@NoWhere.com> - 2020-09-02 12:27 -0500
    Re: Transforming "C" into a Turing equivalent language 006 [credit to Kaz where credit is due] olcott <NoOne@NoWhere.com> - 2020-09-02 11:48 -0500
  Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-08-31 11:18 -0700
    Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-08-31 21:34 +0000
      Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] Juha Nieminen <nospam@thanks.invalid> - 2020-09-01 09:13 +0000
        Re: Transforming "C" into a Turing equivalent language 001 [Providing unlimited memory access to C] boltar@nuttyella.co.uk - 2020-09-01 09:24 +0000

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