Guilty until proven innocent, direct-to-video movies–and those whose theatrical release has been neglible at best–arrive on shelves with two strikes against them. A strange sort of inverse logic says ...

This is a preview. Log in through your library . Abstract We investigate, for several modal logics but concentrating on KT, KD45, S4 and S5, the set of formulas B for which ̅B is provably equivalent ...