Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism)

From	Alan Smaill <smaill@SPAMinf.ed.ac.uk>
Newsgroups	comp.theory
Subject	Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism)
Date	2020-07-02 08:53 +0100
Message-ID	<fweo8oyic8h.fsf@foxtrot.inf.ed.ac.uk> (permalink)
References	(16 earlier) <6KCdnQFbQe5ZRGbDnZ2dnUU7-TvNnZ2d@giganews.com> <rdgo8v$gad$1@dont-email.me> <JJOdnZ5Kc7SKdWbDnZ2dnUU7-WHNnZ2d@giganews.com> <rdgr40$tjm$1@dont-email.me> <COednUo1m9EDaGbDnZ2dnUU7-TvNnZ2d@giganews.com>

Show all headers | View raw

olcott <NoOne@NoWhere.com> writes:

> On 6/30/2020 9:06 PM, André G. Isaak wrote:
[..]
>> Gödel shows that, for any formal system which satisfies the
>> requirements he lays out, it is possible to construct a Gödel
>> sentence. If we simply interpret what you write above in an informal
>> sense and ignore your silly quantifiers, then Gödel effectively
>> demonstrates that this is *true*.
>
> Ah but here's the catch how can we prove that a sentence that asserts
> it is logically equivalent to its own unprovability is true without
> forming a contradiction?

No need to show the sentence true, no need for a contradiction, and
arguing for truth is not part of the *conclusion* of Goedel's original
proof.

There is a syntactic notion of completeness that is perfectly fine
here -- T is complete if for every sentence S, T |- S, or T |- not S.

In a situation like Robinson arithemetic, the negation of this
is provable.

No contradiction here, and this is enough to show incompleteness.

-- 
Alan Smaill

Back to comp.theory | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-26 20:03 -0500
  Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-26 20:53 -0700
    Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-26 23:46 -0500
      Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-26 22:54 -0700
        Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-27 11:04 -0500
    Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 Alan Smaill <smaill@SPAMinf.ed.ac.uk> - 2020-06-27 10:24 +0100
      Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-27 11:14 -0500
        Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-27 09:38 -0700
          Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-27 11:58 -0500
            Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-27 11:54 -0700
              Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-27 15:26 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-27 14:52 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-27 17:09 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-27 17:43 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-27 19:46 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-27 20:15 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-27 22:11 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-28 16:32 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 David Kleinecke <dkleinecke@gmail.com> - 2020-06-28 14:43 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 olcott <NoOne@NoWhere.com> - 2020-06-28 16:59 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 André G. Isaak <agisaak@gm.invalid> - 2020-06-28 20:18 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-28 21:45 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-28 21:27 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-28 21:59 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-29 00:48 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-28 23:57 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-29 13:28 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-29 12:33 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-29 14:33 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-29 13:52 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-29 15:02 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-29 14:14 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-29 15:39 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-29 15:13 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-29 17:09 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-29 21:21 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-30 01:09 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-30 00:24 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-30 16:46 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-30 16:46 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-30 18:24 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-30 18:15 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-30 19:33 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-30 19:18 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-30 20:34 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-30 20:06 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-30 21:31 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-06-30 20:54 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-01 11:03 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-01 10:35 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-01 17:35 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) Chris Buckley <alan@sabir.com> - 2020-07-01 22:47 +0000
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-02 07:01 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-02 10:51 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-02 10:46 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-02 13:59 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-02 13:37 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) Alan Smaill <smaill@SPAMinf.ed.ac.uk> - 2020-07-02 08:53 +0100
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-02 09:52 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) Chris Buckley <alan@sabir.com> - 2020-07-02 15:06 +0000
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-02 10:56 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) Chris Buckley <alan@sabir.com> - 2020-07-02 22:52 +0000
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-02 18:35 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) Chris Buckley <alan@sabir.com> - 2020-07-02 23:48 +0000
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-02 18:57 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) David Kleinecke <dkleinecke@gmail.com> - 2020-07-02 19:22 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-02 22:03 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-02 23:13 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-03 00:36 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-02 23:43 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-03 12:50 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-03 12:19 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-03 13:21 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-03 12:33 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-03 13:48 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-03 13:55 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-03 13:06 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-03 13:07 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-03 12:56 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-03 14:14 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-03 13:38 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-03 15:59 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-03 22:54 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-04 08:56 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-04 08:12 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-07-04 10:06 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) André G. Isaak <agisaak@gm.invalid> - 2020-07-04 09:31 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V20 (Text Analysis) olcott <NoOne@NoWhere.com> - 2020-07-04 14:31 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V20 (Text Analysis) André G. Isaak <agisaak@gm.invalid> - 2020-07-04 15:17 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V20 (Text Analysis) olcott <NoOne@NoWhere.com> - 2020-07-04 17:29 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) olcott <NoOne@NoWhere.com> - 2020-07-05 13:01 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-07-05 16:40 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) olcott <NoOne@NoWhere.com> - 2020-07-05 23:52 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-07-06 00:53 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) olcott <NoOne@NoWhere.com> - 2020-07-06 10:15 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) David Kleinecke <dkleinecke@gmail.com> - 2020-07-06 08:33 -0700
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) olcott <NoOne@NoWhere.com> - 2020-07-06 11:49 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) André G. Isaak <agisaak@gm.invalid> - 2020-07-06 11:27 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) olcott <NoOne@NoWhere.com> - 2020-07-07 22:22 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) André G. Isaak <agisaak@gm.invalid> - 2020-07-06 10:48 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) André G. Isaak <agisaak@gm.invalid> - 2020-07-06 13:55 -0600
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) olcott <NoOne@NoWhere.com> - 2020-07-07 22:13 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V23 (Newspeak) olcott <NoOne@NoWhere.com> - 2020-07-07 22:44 -0500
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) Alan Smaill <smaill@SPAMinf.ed.ac.uk> - 2020-06-30 11:17 +0100
                Re: Simply defining Gödel Incompleteness and Tarski Undefinability away V13 (Isomorphism) olcott <NoOne@NoWhere.com> - 2020-06-30 08:44 -0500

csiph-web