On the semantics of Strategy Logic

We define and study a slight variation on the semantics of Strategy Logic: while in the classical semantics, all strategies are shifted during the evaluation of temporal modalities, we propose to only shift the strategies that have been assigned to a player, thus matching the intuition that we can assign the very same strategy to the players at different points in time. We prove that surprisingly, this renders the model-checking problem undecidable. (C) 2015 Elsevier B.V. All rights reserved.