IF and Epistemic Action Logic

Abstract

This paper is a tentative discussion about the alleged opposition between van Benthem’s account of logic games (Epistemic Action Logic, EAL) and Hintikka’s IF first-order logic. Both logics provide a specific viewpoint on the relationship between logic and games, especially games of imperfect information. Arguing for a cooperative vs. competitive strategy, we will combine EAL and IF logic and obtain natural formulations of the existence of a uniform winning strategy for the verifier in an evaluation game. One of the upshots of the combination IF-EAL is a well known result usually put forward about IF-languages, namely that a sentence is equivalent to its truth-conditions, formulated in a new frame.