Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: Overcoming the proof of undecidability of the Halting Problem by a simple example in C Date: Fri, 16 May 2025 22:49:09 -0500 Organization: A noiseless patient Spider Lines: 59 Message-ID: <10090vl$6mor$2@dont-email.me> References: <1005jsk$3akrk$1@dont-email.me> <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> <1007mp8$3r37u$1@dont-email.me> <1008jgl$j63$3@dont-email.me> <1008o88$1bg1$1@dont-email.me> <1008s18$5uqc$1@dont-email.me> <1008t5g$1bg1$2@dont-email.me> <1008tr4$66kl$2@dont-email.me> <100901g$1bg1$3@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 17 May 2025 05:49:10 +0200 (CEST) Injection-Info: dont-email.me; posting-host="6ea8251727358be87ec7627194d1f4d0"; logging-data="219931"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18/PE+ftVjt0DoEPawaJAgY" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:yYCPmSxV5FCsWA7kBhkTzRXnO5Q= In-Reply-To: <100901g$1bg1$3@dont-email.me> X-Antivirus: Norton (VPS 250516-6, 5/16/2025), Outbound message Content-Language: en-US X-Antivirus-Status: Clean On 5/16/2025 10:33 PM, Richard Heathfield wrote: > On 17/05/2025 03:55, olcott wrote: >> On 5/16/2025 9:44 PM, Richard Heathfield wrote: >>> On 17/05/2025 03:24, olcott wrote: > > > >>>> >>>> When you dishonestly remove the context that you are >>>> replying to fools might think that your rebuttal has merit. >>> >>> The context you claim was 'dishonestly' removed is: >>> >>> void DDD() >>> { >>>     HHH(DDD); >>>     return; >>> } >>> >>> with which we are all too, too familiar. >>> >>> The context merely shows that the only information HHH receives is a >>> pointer to a function. >>> >>> That's not enough for HHH to be able to do what you claim for it >>> *within the rules of C*. >>> >> >> Unless there is also an interpreter also written in C. > > No, not even then, for reasons I have already explained. > >> Any competent C programmer would know that C programs >> can be simulated by C interpreters. If they don't know >> this then that are not competent. > > A C interpreter (eg CH or CINT, both of which have Wiki pages, in case > you're interested) doesn't simulate C code. It interprets C code. You > don't pass C code to HHH in the form of a char * - "void > DDD()\n{\n\tHHH(DDD);\n\treturn;\n}\n", say - to HHH(). You pass a > function pointer. All HHH() can do with that pointer value is: > It is possible to create a C function that simulates the source-code of other C functions. The essential idea of this is a C interpreter. The actual HHH uses x86 emulation that is way over most peoples heads. When I said that HHH simulates DDD reviewers are not free to ignore the word "simulate". They do this because they only glance at a couple of my words to artificially contrive some fake rebuttal. -- Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer