Формальная i пропозициональная логика А. Виссера и ее расширения.

Abstract

Extensions o f formal propositional logic by A. Visser (1980) are discusecl. There is a continuum o f such logics which are axiomatized by onevariables formulas. There is an extension o f formal propositional logic which is closed under modus ponens , is o f width 2, but is not Kripke-complete.