Forums before death by AOL, social media and spammers... "We can't have nice things"
|    sci.logic    |    Logic -- math, philosophy & computationa    |    262,912 messages    |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
|    Message 261,616 of 262,912    |
|    olcott to Tristan Wibberley    |
|    Re: A new category of thought    |
|    01 Dec 25 20:01:19    |
      XPost: comp.theory, sci.math, sci.lang       From: polcott333@gmail.com              On 12/1/2025 7:39 PM, Tristan Wibberley wrote:       > On 01/12/2025 11:02, Mikko wrote:       >> olcott kirjoitti 29.11.2025 klo 23.59:       >>       >> G := (F ⊬ G) // G says of itself that it is unprovable in F       >>       >> With a reasonable type system that is a type error:       >> - the symbol ⊬ requires a sentence on the right side       >       > If we're using it in its normal epitheoretic meaning. I think Olcott is       > using it as a predicative object of a logistic F so it requires a       > formula on the right? That's not unreasonable since we take       >       > A |- B       >       > as a shorthand for       >       > |-A => |-B       >       > leaving us with "B is a formula" to which the unary predicate |- may be       > applied to make a statement.       >              The first incompleteness theorem states that in any       consistent formal system F within which a certain       amount of arithmetic can be carried out, there are       statements of the language of F which can neither       be proved nor disproved in F.       https://plato.stanford.edu/entries/goedel-incompleteness/              (G) F ⊢ GF ↔ ¬ProvF(┌GF┐)       https://plato.stanford.edu/entries/goedel-incompleteness/#FirIncTheCom              G ↔ ¬Prov(⌜G⌝)       Directed Graph of evaluation sequence       00 ↔ 01 02       01 G       02 ¬ 03       03 Prov 04       04 Gödel_Number_of 01 // cycle thus stuck in infinite evaluation loop                     *YACC Syntax of Olcott Minimal Type Theory*       https://philarchive.org/archive/PETMTT-4v2       I used the "defined as" operator to allow       direct self-reference.              > It's the epitheoretic "=>" that takes a statement on the right, but       > clearly it's more complex because systems and lists of statements can be       > used on the left. Olcott's use of |- as a predicative object of F is       > clearly awkwardly ambiguous, as tempting as it may be.       >       > The extra awkward thing here is that F is capable of using |- in its own       > formulae, making its (normal) use as a unary predicate redundant and       > perhaps obstructive leaving us with a system whose statements are       > exactly its formulas unless we have a unary predicative with no visible       > elements, if it's not nonsense for any other reasons.       >       > I wonder if that may not be done for some reason. There are lots of       > reasons to be concerned about it.       >       >> - the value of the ⊬ operation is a truth value       >       > /Should/ we take ⊬ to be an operation here? or just a predicative object       > of F?       >       >> - the symbol := requires the same type on both sides       >       > Unless it's an operation (as in, an action to be done to generate       > sentences/formulas of the system being analysed). When G is an       > epitheoretic object rather than an object of a definition extension of F       > then I think it /must/ be such an operation.       >       >                     --       Copyright 2025 Olcott              My 28 year goal has been to make       "true on the basis of meaning" computable.              This required establishing a new foundation       for correct reasoning.              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
(c) 1994, bbs@darkrealms.ca