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Path: ...!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott <polcott333@gmail.com> Newsgroups: sci.logic Subject: Re: This makes all Analytic(Olcott) truth computable --- ZFC Date: Wed, 21 Aug 2024 07:37:50 -0500 Organization: A noiseless patient Spider Lines: 149 Message-ID: <va4n2u$3s0hu$3@dont-email.me> References: <v86olp$5km4$1@dont-email.me> <v91p95$3ppav$1@dont-email.me> <v92q4f$37e9$1@dont-email.me> <v94l1p$ldq7$1@dont-email.me> <v95c2j$p5rb$4@dont-email.me> <v95cke$p5rb$5@dont-email.me> <v977fo$gsru$1@dont-email.me> <v97goj$ielu$1@dont-email.me> <v9c93e$35sg6$1@dont-email.me> <v9d3k1$3ajip$1@dont-email.me> <v9ffpr$3s45o$1@dont-email.me> <v9fkd4$3se8c$1@dont-email.me> <v9kg66$tdvb$1@dont-email.me> <v9nbjf$1dj8q$1@dont-email.me> <20b1dea98eda49e74e822c96b37565bb3eb36013@i2pn2.org> <v9o4p2$1h5u4$1@dont-email.me> <cd12fb81fcd05d2e112fc8aca2f5b791c521cfc9@i2pn2.org> <v9oddf$1i745$2@dont-email.me> <7f2a1f77084810d4cee18ac3b44251601380b93a@i2pn2.org> <v9ogmp$1i745$6@dont-email.me> <662de0ccc3dc5a5f0be0918d340aa3314d51a348@i2pn2.org> <v9oj4r$1i745$8@dont-email.me> <v9sibq$2bq1o$1@dont-email.me> <v9sn85$2c67u$6@dont-email.me> <v9v0u0$2qajg$1@dont-email.me> <v9vgbu$2rjt1$13@dont-email.me> <va1qmi$3biht$1@dont-email.me> <va27ge$3cvgv$7@dont-email.me> <va4a0u$3q89u$1@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Wed, 21 Aug 2024 14:37:51 +0200 (CEST) Injection-Info: dont-email.me; posting-host="6fc4e6078b6f11ac657df23e0012e04d"; logging-data="4063806"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19wUipS3G+V5zDzwugYLT/W" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Xzx97jU5qy8HP72H24dcbM5tNik= In-Reply-To: <va4a0u$3q89u$1@dont-email.me> Content-Language: en-US Bytes: 8115 On 8/21/2024 3:54 AM, Mikko wrote: > On 2024-08-20 13:59:42 +0000, olcott said: > >> On 8/20/2024 5:21 AM, Mikko wrote: >>> On 2024-08-19 13:12:30 +0000, olcott said: >>> >>>> On 8/19/2024 3:49 AM, Mikko wrote: >>>>> On 2024-08-18 11:51:33 +0000, olcott said: >>>>> >>>>>> On 8/18/2024 5:28 AM, Mikko wrote: >>>>>>> On 2024-08-16 22:16:59 +0000, olcott said: >>>>>>> >>>>>>>> On 8/16/2024 5:03 PM, Richard Damon wrote: >>>>>>>>> On 8/16/24 5:35 PM, olcott wrote: >>>>>>>>>> On 8/16/2024 4:05 PM, Richard Damon wrote: >>>>>>>>>>> On 8/16/24 4:39 PM, olcott wrote: >>>>>>>>>>>> >>>>>>>>>>>> ZFC didn't need to do that. All they had to do is >>>>>>>>>>>> redefine the notion of a set so that it was no longer >>>>>>>>>>>> incoherent. >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> I guess you haven't read the papers of Zermelo and Fraenkel. >>>>>>>>>>> They created a new definition of what a set was, and then >>>>>>>>>>> showed what that implies, since by changing the definitions, >>>>>>>>>>> all the old work of set theory has to be thrown out, and then >>>>>>>>>>> we see what can be established. >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> None of this is changing any more rules. All >>>>>>>>>> of these are the effects of the change of the >>>>>>>>>> definition of a set. >>>>>>>>>> >>>>>>>>> >>>>>>>>> No, they defined not only what WAS a set, but what you could do >>>>>>>>> as basic operations ON a set. >>>>>>>>> >>>>>>>>> Axiom of extensibility: the definition of sets being equal, >>>>>>>>> that ZFC is built on first-order logic. >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> Axion of regularity/Foundation: This is the rule that a set can >>>>>>>>> not be a member of itself, and that we can count the members of >>>>>>>>> a set. >>>>>>>>> >>>>>>>> This one is the key that conquered Russell's Paradox. >>>>>>>> If anything else changed it changed on the basis of this change >>>>>>>> or was not required to defeat RP. >>>>>>> >>>>>>> That is not sufficient. They also had to Comprehension. >>>>>>> >>>>>>>>> Axiom Schema of Specification: We can build a sub-set from >>>>>>>>> another set and a set of conditions. (Which implies the >>>>>>>>> existance of the empty set) >>>>>>> >>>>>>> This is added to keep most of Comprenesion but not Russell's set. >>>>>>> >>>>>> >>>>>> All they did was (as I already said) was redefine the notion of a >>>>>> set. >>>>>> That this can still be called set theory seems redundant. >>>>> >>>>> They did, as both Richard Damon and I already said, much more. They >>>>> also explained their rationale, worked out various consequnces of >>>>> their axioms and compared them to expectations, and developed better >>>>> sets of axioms. >>>>> >>>> >>>> They made no other changes to the notion of set theory >>>> than redefining what a set is. Even then it seems they >>>> did less than this. >>> >>> That is so obvious that needs not be mentined. There is nothing >>> in the set theory expept what a set is so obviously nothing else >>> can be changed. >>> >> >> There are at least two tings in set theory: >> (a) What a set is >> (b) How a set works > > They are the same thing. There is nothing in a set other than how > a set works. And it does not work in any way other than having > certain relations to other sets. > >> When how a set is constructed is changed this single >> change has great impact yet is still only one change. > > That is true. Therefore one must be careful with the construction > rules and ensure that non-existent or undesiderable sets cannot > be constructed but all sets that are regarded necessary can be > constructed. > >>>> From what I recall it seems that they only changed how >>>> sets can be constructed. The operations that can be >>>> performed on sets remained the same. >>> >>> There are axioms about exstence and non-existence of certain kind of >>> sets. For example, the axiom of regularity (aka foudation) specifies >>> that ill-founded sets (e.g., Quine's atom) do not exist. >>> >>>>> One consequence of ZF axioms is that there is no set that contains all >>>>> other sets as members. Some regard this as a defect and have developed >>>>> set thories that have a universal set that contains all other sets as >>>>> members (and usually itself, too). >>>> >>>> Then maybe they did this incorrectly. They only needed to >>>> specify that a set cannot be a member of itself when a >>>> set is constructed. This would not preclude a universal >>>> set of all other sets. >>> >>> The power set axiom prevents the existence of a set that contains >>> all other sets. >> >> In mathematics, the axiom of power set[1] is one of the >> Zermelo–Fraenkel axioms of axiomatic set theory. It >> guarantees for every set x the existence of a set P(x) >> the power set of x consisting precisely of the subsets of x. >> https://en.wikipedia.org/wiki/Axiom_of_power_set >> >> *It simply corrected the error of this* >> In mathematics, the power set (or powerset) of a set S >> is the set of all subsets of S, including the empty set >> and S itself. >> https://en.wikipedia.org/wiki/Power_set > > What was the error and what was the correction? > Anyway, the pawer set axiom of ZF ensures that for every set S > that is neither its own member nor a member of its member there > is another set cointaing a member that is not S and not a member of S. > >>> Set theories with an unversal set need to restrict >>> the construction operations more than what is usually considered >>> reasonable. >> >> I don't see how. The set of all sets that do not contain >> themselves simply becomes the set of all sets. > > The set of all sets that do not contain themselves is the Russell set > that revealied the inconsistency of the naive set theory. The main > improvment in ZF was the non-existence of this set. > So basically you agreed with me on everything. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer