Path: csiph.com!news.swapon.de!newsreader4.netcologne.de!news.netcologne.de!peer03.ams1!peer.ams1.xlned.com!news.xlned.com!peer03.ams4!peer.am4.highwinds-media.com!news.highwinds-media.com!fx05.ams4.POSTED!not-for-mail From: Mr Flibble Newsgroups: comp.lang.c++,comp.lang.c,comp.software-eng Subject: Re: Software engineers needed to validate this Message-ID: <20220711182139.00000032@reddwarf.jmc.corp> References: <2badnek-GtlvpFH_nZ2dnUU7_8zNnZ2d@giganews.com> Organization: Jupiter Mining Corporation X-Newsreader: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Lines: 52 X-Complaints-To: abuse@eweka.nl NNTP-Posting-Date: Mon, 11 Jul 2022 17:21:41 UTC Date: Mon, 11 Jul 2022 18:21:39 +0100 X-Received-Bytes: 2413 Xref: csiph.com comp.lang.c++:85097 comp.lang.c:166637 comp.software-eng:3591 On Mon, 11 Jul 2022 09:55:45 -0500 olcott wrote: > Only an ordinary understanding of C and software engineering is > required. > > #define ptr uintptr_t > > int H(ptr p, ptr i); // simulating halt decider > > H Simulates its input until it correctly predicts that this simulated > input would never terminate normally then rejects this input as > non-halting. > > void P(ptr x) > { > if (H(x, x)) > HERE: goto HERE; > return; > } > > int main() > { > Output("Input_Halts = ", H(P, P)); > } > > When the execution trace of function P() simulated by function H() > shows: (1) Function H() is called from P(). > (2) With the same parameters to H(). > (3) With no instructions in P() that could escape this infinitely > recursive simulation: {index jump, conditional branch, return} > > Then the function call from P() to H() would never terminate normally. > In this case H aborts its simulation of P and rejects its input as > non-halting. > Can you not post your crap to this newsgroup (comp.lang.c++) please? And you seem to need reminding YET AGAIN of the following: I have shown with my signaling halting decider there is no need for a call to a simulation-based halting decider, H, from the input program to be recursive; this is compatible with [Strachey 1965] and associated proofs which are not recursive in nature. Your H is invalid as it aborts the simulation to prevent infinite recursion rather than returning an answer to its caller which results in it giving the wrong answer for a non-pathological input that calls H. /Flibble