Comment on Supernatural Math

Tue, 19 May 2009 19:52:56 GMT

If putting 2 S's next to 2 S's got us 3 S's, we could prove 2+2=3 in PA with the usual definition of addition

Nitpick but important: we couldn't actually prove it, just produce a convincing (in that world) false proof (that is actually a proof of a theorem in some other, inconsistent, system with slightly different inference rules).

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