Timeline for A theory which denies the existence of a truth predicate
Current License: CC BY-SA 3.0
8 events
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| Sep 30, 2017 at 15:59 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Jul 12, 2017 at 14:35 | comment | added | Christopher King | @EmilJeřábek Okay, here is an example: mathoverflow.net/a/275276/65915 | |
| Jul 12, 2017 at 12:47 | comment | added | Christopher King | @EmilJeřábek Here it is. | |
| Jul 12, 2017 at 12:33 | comment | added | Christopher King | @EmilJeřábek Oh hmm, I guess formulating such a theory is harder than I thought. I'm going to ask a separate question about it. | |
| Jul 12, 2017 at 12:29 | comment | added | Emil Jeřábek | A truth predicate (in the linked sense) is a proper class. How do you intend to universally quantify in ZFC (or in PA) over proper classes that are not definable? The theory has no means of referring to them. | |
| Jul 12, 2017 at 12:02 | comment | added | Christopher King | @EmilJeřábek mathoverflow.net/a/273121/65915 shows a finite construction of a truth predicate. Also, I'm thinking in terms of second of "there is no function that determines truth" (which is not implied by Tarski's theorem) as opposed to "there is no definable function that determines truth (which is). | |
| Jul 12, 2017 at 8:46 | comment | added | Emil Jeřábek | How would you formulate it? There are several distinct things going under the name “truth predicate”, but generally they are described by an infinite schema, hence you can’t negate it. Anyway, the proof of Tarski’s undefinability theorem gives you a sense in which every theory denies the existence of its truth predicate. | |
| Jul 12, 2017 at 8:01 | history | asked | Christopher King | CC BY-SA 3.0 |