Deutsch English Français Italiano |
<f7af3f113cab3faf180d4cbb0da7f94e35174654@i2pn2.org> View for Bookmarking (what is this?) Look up another Usenet article |
Path: ...!weretis.net!feeder9.news.weretis.net!news.nk.ca!rocksolid2!i2pn2.org!.POSTED!not-for-mail From: Richard Damon <richard@damon-family.org> Newsgroups: comp.theory Subject: =?UTF-8?Q?Re=3A_Analysis_of_Flibble=E2=80=99s_Latest=3A_Detecting_v?= =?UTF-8?Q?s=2E_Simulating_Infinite_Recursion_ZFC?= Date: Fri, 23 May 2025 12:01:55 -0400 Organization: i2pn2 (i2pn.org) Message-ID: <f7af3f113cab3faf180d4cbb0da7f94e35174654@i2pn2.org> References: <Ms4XP.801347$BFJ.668081@fx13.ams4> <95db078e80b2868ed15a9a9a2af0280d96234a3a@i2pn2.org> <100jo18$2mhfd$1@dont-email.me> <100jpv9$2m0ln$4@dont-email.me> <100kt0c$2tae8$3@dont-email.me> <100ktr7$2reaa$1@dont-email.me> <100l09v$2tae8$5@dont-email.me> <100l1ov$2ul3j$1@dont-email.me> <100l3jh$2v0e9$1@dont-email.me> <100l5c8$2ul3j$2@dont-email.me> <87frgvxzsl.fsf@bsb.me.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 23 May 2025 16:02:15 -0000 (UTC) Injection-Info: i2pn2.org; logging-data="1608170"; mail-complaints-to="usenet@i2pn2.org"; posting-account="diqKR1lalukngNWEqoq9/uFtbkm5U+w3w6FQ0yesrXg"; User-Agent: Mozilla Thunderbird X-Spam-Checker-Version: SpamAssassin 4.0.0 In-Reply-To: <87frgvxzsl.fsf@bsb.me.uk> Content-Language: en-US Bytes: 4608 Lines: 81 On 5/23/25 8:43 AM, Ben Bacarisse wrote: > Richard Heathfield <rjh@cpax.org.uk> writes: > >> On 21/05/2025 18:47, olcott wrote: > ... >>> *PAY ATTENTION* >>> I am saying that a key element of the halting problem >>> proof cannot exist, thus the proof itself cannot exist. >> >> Yes, it can, and it does. > > You'd think that at some point in decades he's wasted on this he might > have considered looking at the proofs that are not by contradiction. > I've repeatedly suggested looking at Radó's Busy Bee problem and proof. But that would require him to actually THINK and look for truth. > >> Watch. >> >> Definition: a prime number is an integer >= 2 with no divisors >= 2 except >> itself. >> >> Hypothesis: there is no largest prime number. >> >> Proof: >> >> Assume that a largest prime number Pn exists. >> >> Itemise all the prime numbers from P1(=2) up to Pn : >> >> P1 P2 P3 ... Pn >> >> Insert x symbols all the way along. >> >> P1 x P2 x P3 ... x Pn >> >> Add 1. >> >> The number thus calculated is not divisible by any prime in our list (there >> being a remainder of 1 in each case), so the number calculated is (a) >> prime, and (b) larger than Pn. Thus Pn is not the largest prime. This >> contradicts the assumption made at the beginning, which must therefore be >> false. Proof by contradiction. >> >> The proof that no largest prime exists despite its assumption that such a >> prime /does/ exist - an assumption that turns out to be false. > > Interestingly (and not, I think, coincidentally) Euclid's proof is not a > proof by contradiction. It shows (by case analysis) that any finite > list of primes is incomplete. There is (in the way Euclid does it) no > need to assume anything (other than some basic axioms). > > The same strategy can be used for the halting theorem. The more direct > proof essentially shows that the infinite list of Turing machines (there > is only one, once we agree a numbering) does not include a halt decider > (just like it does not include uncountably many other deciders that the > cranks are never interested in). > > PO seems to like talking to you so you might consider avoiding any > arguments about contradictions by providing an outline of the direct > proof instead. > > I've lost count of the times when the proof by contradiction leads > students astray. Even if they don't think it's invalid, every year one > has to counter the idea that all the decider has to do is "spot the > tricky input" and the decider will work on everything else. > >> I'm finding it hard to believe that you can really be this stupid. Perhaps >> you just get off yanking people's chains. > > Hmm... Don't forget Hanlon's razor. As for data points, PO has > published a website whose purpose is to "bring new scripture to the > world" and he has claimed, in a court of law, to be God. > > Incidentally, there is even a modern proof by construction of the > infinitude of the primes. The idea being that since n and (n+1) have no > prime factors in common, n(n+1) has more distinct prime factors that n. > This gives a chain of ever larger sets of primes: the unique prime > factors of 2x3, 6x7, 42x43 and so on. >