Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: "Fred. Zwarts" Newsgroups: comp.theory Subject: Re: Incorrect requirements --- Computing the mapping from the input to HHH(DD) Date: Tue, 13 May 2025 12:58:17 +0200 Organization: A noiseless patient Spider Lines: 78 Message-ID: References: <87msbmeo3b.fsf@nosuchdomain.example.com> <875xiaejzg.fsf@nosuchdomain.example.com> <87jz6qczja.fsf@nosuchdomain.example.com> <1276edeb9893085c59b02bbbd59fe2c64011736b@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Tue, 13 May 2025 12:58:18 +0200 (CEST) Injection-Info: dont-email.me; posting-host="0f93063a85412bb9b83b70aeb6dff6a7"; logging-data="1866990"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18X03fm7WhBD0oEaPyKmfFi" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:13RsbYHqMa7TfUrS2p60wpeJ+tQ= Content-Language: nl, en-GB In-Reply-To: Op 13.mei.2025 om 04:32 schreef olcott: > On 5/12/2025 9:17 PM, Mike Terry wrote: >> On 12/05/2025 02:25, Richard Heathfield wrote: >>> On 12/05/2025 01:38, Mike Terry wrote: >>>> On 11/05/2025 18:11, Richard Heathfield wrote: >>>>> On 11/05/2025 17:44, olcott wrote: >>>>>> Any yes/no question where both yes and no are the >>>>>> wrong answer is an incorrect polar question. >>>>> >>>>> Either DD stops or it doesn't (once it's been hacked around to get >>>>> it to compile and after we've leeched out all the dodgy programming). >>>> >>>> Done that. >>> >>> And you still had code left? >>> >>>> It still stops. >>> >>> Okay. >>> >>>>> If the computer cannot correctly decide whether or not DD halts, >>>> >>>> The decider says it doesn't stop.. >>> >>> I said "cannot >>>correctly<<< decide". >> >> There are infinitely many deciders that could be given the input. >> Some of them decide that particular input correctly, and some >> incorrectly. >> >> PO's HHH is one of the ones that decide incorrectly. >> > > When "correctly" means to report on behavior besides > that behavior that the input actually specifies then > it is wrong. And since the input actually specifies is a halting program, HHH is wrong when it says that it is a non-halting program. If HHH does not take into account the specification in the input, which contains a conditional abort, then HHH ignores the specification in the input. > > When 2 + 3 = 5 this is determined by the rules > of arithmetic. > > When the behavior that the input specifies according > to the rules of the x86 language is non-halting then > HHH must report on this behavior. And when the input specifies a halting program, as proven by direct execution and world-class simulators. HHH must report that behaviour. > > HHH cannot compute the mapping from its input to > the behavior of the directly executed DD() for the > same reason that For the reason that its has a bug which causes a premature abort, that is a problem of HHH. Because of this bug, HHH computes another input than is specified in the input, which is the same as: > > int sum(int x, int y) { return x + y; } > sum(3,2) can not compute any mapping to sum 5 + 7. > THE INPUT SPECIFIES SOMETHING ELSE. > And a buggy sum(int x, int y) { return 1 + x + y; } cannot compute the correct mapping of 3+2=5. A bug in the program does not make the mapping correct. Similarly, the bug in HHH to ignore the most important part of the input, does not make the mapping correct.