Path: ...!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory,sci.logic Subject: Re: Can you see that D correctly simulated by H remains stuck in recursive simulation? Date: Fri, 24 May 2024 17:20:16 -0500 Organization: A noiseless patient Spider Lines: 95 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 25 May 2024 00:20:17 +0200 (CEST) Injection-Info: dont-email.me; posting-host="010db72b80f31f696ef17c51994f71bb"; logging-data="2656935"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19Hl6kUYi67C7YYsN9hqdPw" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:11l4o1y6m3mzLnFBZkFgyHNE32g= In-Reply-To: Content-Language: en-US Bytes: 5259 On 5/24/2024 4:39 PM, olcott wrote: > On 5/24/2024 4:03 PM, Richard Damon wrote: >> On 5/24/24 4:01 PM, olcott wrote: >>> On 5/24/2024 12:25 PM, Richard Damon wrote: >>>> On 5/24/24 1:10 PM, olcott wrote: >>>>> On 5/24/2024 2:37 AM, Fred. Zwarts wrote: >>>>>> Op 23.mei.2024 om 19:04 schreef olcott: >>>>>>> typedef int (*ptr)();  // ptr is pointer to int function in C >>>>>>> 00       int H(ptr p, ptr i); >>>>>>> 01       int D(ptr p) >>>>>>> 02       { >>>>>>> 03         int Halt_Status = H(p, p); >>>>>>> 04         if (Halt_Status) >>>>>>> 05           HERE: goto HERE; >>>>>>> 06         return Halt_Status; >>>>>>> 07       } >>>>>>> 08 >>>>>>> 09       int main() >>>>>>> 10       { >>>>>>> 11         H(D,D); >>>>>>> 12         return 0; >>>>>>> 13       } >>>>>>> >>>>>>> The above template refers to an infinite set of H/D pairs where D is >>>>>>> correctly simulated by pure function H. This was done because many >>>>>>> reviewers used the shell game ploy to endlessly switch which H/D >>>>>>> pair >>>>>>> was being referred to. >>>>>>> >>>>>>> *Correct Simulation Defined* >>>>>>>     This is provided because every reviewer had a different >>>>>>> notion of >>>>>>>     correct simulation that diverges from this notion. >>>>>>> >>>>>>>     A simulator is an x86 emulator that correctly emulates at >>>>>>> least one >>>>>>>     of the x86 instructions of D in the order specified by the x86 >>>>>>>     instructions of D. >>>>>>> >>>>>>>     This may include correctly emulating the x86 instructions of >>>>>>> H in >>>>>>>     the order specified by the x86 instructions of H thus calling >>>>>>> H(D,D) >>>>>>>     in recursive simulation. >>>>>>> >>>>>>> *Execution Trace* >>>>>>>     Line 11: main() invokes H(D,D); H(D,D) simulates lines 01, >>>>>>> 02, and 03 >>>>>>>     of D. This invokes H(D,D) again to repeat the process in endless >>>>>>>     recursive simulation. >>>>>>> >>>>>> >>>>>> Of course this depends very much on the exact meaning of 'correct >>>>>> simulation', or 'correctly emulating'. >>>>> >>>>> Not when these are defined above. >>>>> >>>>>> E.g., take the call to H(p, p). If H recognizes that it is a call >>>>>> to a H with the same algorithm as is it using itself, and it knows >>>>>> that itself returns a certain integer value K, than it can be >>>>>> argued that it is a correct emulation to substitute the call to H >>>>>> with this integer value K, which is assigned to Halt_Status. Then >>>>>> the simulation of D can proceed to line 04. >>>>>> What we need is an exact definition of 'correct simulation', in this >>>>> >>>>> No, you simply need to pay complete attention to the fact that this >>>>> has already been provided. >>>>> >>>>> I have been over the exact same issue with dozens and dozen of people >>>>> though hundreds and hundreds of messages over two years. >>>> >>>> Excpet that we have two contradictory definitions present, >>> >>> Yes you have a definition of simulation where the x86 machine >>> language of D is simulated incorrectly or in the wrong order. >> >> Nope. The UTM definition still simulates EVERY x86 machine language >> instruction of D simulated correctly in the exact order. The added >> requirement is that we look at a simulation that is never aborted. > > H is a pure function that always returns 56 at some point other > than that H is isomorphic to a UTM. > I have learned from decades as a software engineer that complexity is only manageable when it is isolated and minimized. It is impossible to correctly understand termination analyzer H until after one first has 100% perfectly complete and total understanding of pure function simulator H/D pairs. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer