Reducibility of formulae of weak second order arithmetic to pseudo-canonical forms Reinhold Kołodziej OriginalPaper Pages: 233 - 258
On quantity of logical values in the discussive D2 system and in modular logic Jerzy Kotas BriefCommunication Pages: 273 - 275
Semantical analyses of propositional systems of Fitch and Nelson Richard Routley OriginalPaper Pages: 283 - 298