Deutsch   English   Français   Italiano  
<100ceum$uvq0$1@dont-email.me>

View for Bookmarking (what is this?)
Look up another Usenet article

Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Richard Heathfield <rjh@cpax.org.uk>
Newsgroups: comp.theory
Subject: Re: Overcoming the proof of undecidability of the Halting Problem by
 a simple example in C
Date: Sun, 18 May 2025 12:05:58 +0100
Organization: Fix this later
Lines: 38
Message-ID: <100ceum$uvq0$1@dont-email.me>
References: <1005jsk$3akrk$1@dont-email.me>
 <bc6f0f045212bdfb7f7d883426873a09e37789ea@i2pn2.org>
 <1005u6v$3cpt2$1@dont-email.me> <1005v0p$3b07v$1@dont-email.me>
 <10063u0$3dmiv$1@dont-email.me> <1006on8$3l9t7$1@dont-email.me>
 <1007kgq$3qb7l$9@dont-email.me> <1009lm9$b15q$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sun, 18 May 2025 13:06:02 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="99c2e759ba7e03b4721635ed22ed06d2";
	logging-data="1015616"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18O128FLmoC8AeBpj3KspOeOJlCA1jaLwVQiGxnJohW1w=="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:Ao8c9VFrBwyPctkv+9v/nehxaWQ=
Content-Language: en-GB
In-Reply-To: <1009lm9$b15q$1@dont-email.me>

On 17/05/2025 10:42, Mikko wrote:
> On 2025-05-16 15:10:18 +0000, olcott said:
> 

<snip>

>> void DDD()
>> {
>>    HHH(DDD);
>>    return;
>> }
>>
>> Anyone that knows C can tell that when HHH does simulate
>> DDD correctly that it keeps getting deeper in recursive
>> simulation until aborted or OOM error.
> 
> No, there are peole who do know C but don't know that HHH is not
> void HHH(void (*f)(void)) {}

If they know C they should know that it's
  u32 HHH(void (*P)()), according to Halt7.c.

It takes a pointer to a function that accepts no arguments and 
returns no value.

Anyone who knows C will know that HHH can call the function 
pointed to, pass it on to another function as a parameter, or 
store the value. If it does anything else with that value (which 
of course it *does*), C washes its hands of the consequences. Mr 
Olcott is mistaken to think that HHH()'s behaviour can be 
determined by the rules of C.

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
Sig line 4 vacant - apply within