[FOM] 581: Impossible Counting/more
Harvey Friedman
hmflogic at gmail.com
Tue Jun 2 05:55:08 EDT 2015
In http://www.cs.nyu.edu/pipermail/fom/2015-May/018752.html there is a
silly typo. gmail wrote
I said that PA is interpretable in RCA_0 + BWQ. This shows very
fantastically that Con(RCA_0 + BWQ) implies Con(PA). However, RCA_0 +
BWQ does not prove Con(PA).
when I meant
fI said that PA is interpretable in RCA_0 + BWQ. This shows very
FINITISTICALLY that Con(RCA_0 + BWQ) implies Con(PA). However, RCA_0 +
BWQ does not prove Con(PA).
In fact, one also gets that
RCA_0 + BWQ proves the consistency of every finite fragment of PA
and the above is also proved very finitistically.
############################
I updated the manuscript to
https://u.osu.edu/friedman.8/foundational-adventures/downloadable-manuscripts/
#88. Impossible Counting, June 2, 2015, 10 pages, draft.
I added that Theta'(k) is recursively unsolvable if we use only finite
bops. Also this at the end;
We can measure how well a standard extension does in computing
Theta(12). Specifically, let Theta(12,T) be the least n such that T
proves that Theta(12) <= n.
THEOREM 3.4. Let T,T' be standard extensions as in Theorem 3.3,
neither proving the inconsistency of itself. If T' proves the
consistency of T then Theta(12,T') < Theta(12,T).
We have not been precise about the exact finite list of standard
extensions (of ZFC and ZF by large cardinal hypotheses) that we are
using. This will be presented at a later time. The list will include
ZFC + "there is a nontrivial elementary embedding from some
V(lambda+1) into V(lambda+1)".
NBG + "there is a nontrivial elementary embedding from V into V".
************************************************************
My website is at https://u.osu.edu/friedman.8/ and my youtube site is at
https://www.youtube.com/channel/UCdRdeExwKiWndBl4YOxBTEQ
This is the 581st in a series of self contained numbered
postings to FOM covering a wide range of topics in f.o.m. The list of
previous numbered postings #1-527 can be found at the FOM posting
http://www.cs.nyu.edu/pipermail/fom/2014-August/018092.html
528: More Perfect Pi01 8/16/14 5:19AM
529: Yet more Perfect Pi01 8/18/14 5:50AM
530: Friendlier Perfect Pi01
531: General Theory/Perfect Pi01 8/22/14 5:16PM
532: More General Theory/Perfect Pi01 8/23/14 7:32AM
533: Progress - General Theory/Perfect Pi01 8/25/14 1:17AM
534: Perfect Explicitly Pi01 8/27/14 10:40AM
535: Updated Perfect Explicitly Pi01 8/30/14 2:39PM
536: Pi01 Progress 9/1/14 11:31AM
537: Pi01/Flat Pics/Testing 9/6/14 12:49AM
538: Progress Pi01 9/6/14 11:31PM
539: Absolute Perfect Naturalness 9/7/14 9:00PM
540: SRM/Comparability 9/8/14 12:03AM
541: Master Templates 9/9/14 12:41AM
542: Templates/LC shadow 9/10/14 12:44AM
543: New Explicitly Pi01 9/10/14 11:17PM
544: Initial Maximality/HUGE 9/12/14 8:07PM
545: Set Theoretic Consistency/SRM/SRP 9/14/14 10:06PM
546: New Pi01/solving CH 9/26/14 12:05AM
547: Conservative Growth - Triples 9/29/14 11:34PM
548: New Explicitly Pi01 10/4/14 8:45PM
549: Conservative Growth - beyond triples 10/6/14 1:31AM
550: Foundational Methodology 1/Maximality 10/17/14 5:43AM
551: Foundational Methodology 2/Maximality 10/19/14 3:06AM
552: Foundational Methodology 3/Maximality 10/21/14 9:59AM
553: Foundational Methodology 4/Maximality 10/21/14 11:57AM
554: Foundational Methodology 5/Maximality 10/26/14 3:17AM
555: Foundational Methodology 6/Maximality 10/29/14 12:32PM
556: Flat Foundations 1 10/29/14 4:07PM
557: New Pi01 10/30/14 2:05PM
558: New Pi01/more 10/31/14 10:01PM
559: Foundational Methodology 7/Maximality 11/214 10:35PM
560: New Pi01/better 11/314 7:45PM
561: New Pi01/HUGE 11/5/14 3:34PM
562: Perfectly Natural Review #1 11/19/14 7:40PM
563: Perfectly Natural Review #2 11/22/14 4:56PM
564: Perfectly Natural Review #3 11/24/14 1:19AM
565: Perfectly Natural Review #4 12/25/14 6:29PM
566: Bridge/Chess/Ultrafinitism 12/25/14 10:46AM
567: Counting Equivalence Classes 1/2/15 10:38AM
568: Counting Equivalence Classes #2 1/5/15 5:06AM
569: Finite Integer Sums and Incompleteness 1/515 8:04PM
570: Philosophy of Incompleteness 1 1/8/15 2:58AM
571: Philosophy of Incompleteness 2 1/8/15 11:30AM
572: Philosophy of Incompleteness 3 1/12/15 6:29PM
573: Philosophy of Incompleteness 4 1/17/15 1:44PM
574: Characterization Theory 1 1/17/15 1:44AM
575: Finite Games and Incompleteness 1/23/15 10:42AM
576: Game Correction/Simplicity Theory 1/27/15 10:39 AM
577: New Pi01 Incompleteness 3/7/15 2:54PM
578: Provably Falsifiable Propositions 3/7/15 2:54PM
579: Impossible Counting 5/26/15 8:58PM
580: Goedel's Second Revisited 5/29/15 5:52 AM
Harvey Friedman
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