Isomorphisms in a Category of Proofs – Greg Restall

In this talk, I show how a category of classical proofs can give rise to three different hyperintensional notions of sameness of content. One of these notions is very fine-grained, going so far as to distinguish p and p∧p, while identifying other distinct pairs of formulas, such as p∧q and q∧p; p and ¬¬p; or ¬(p∧q) and ¬p∨¬q. Another relation is more coarsely grained, and gives the same account of identity of content as equivalence in Angell’s logic of analytic containment. A third notion of sameness of content is defined, which is intermediate between Angell’s and Parry’s logics of analytic containment. Along the way we show how purely classical proof theory gives resources to define hyperintensional distinctions thought to be the domain of properly non-classical logics

Logic & Metaphysics Workshop

Feb 26 Martin Pleitz, Muenster
Mar 5 Vera Flocke, NYU
Mar 12 Roy Sorensen, WUSTL
Mar 19 Alex Citkin, Private Researcher
Mar 26 Chris Scambler, NYU
Apr 2 SPRING RECESS. NO MEETING
Apr 9 Greg Restall, Melbourne
Apr 16 Daniel Nolan, Notre Dame
Apr 23 Mel Fitting, CUNY
Apr 30 Sungil Han, Seoul National
May 7 Andreas Ditter, NYU
May14 Rohit Parikh