Colloque avec actes sans comité de lecture.The framework of computational systems has been already used for describing several computational logics. In this paper is described the way a propositional prover and a predicate prover are implemented in ELAN, the system developed in Nancy for describing and executing computational systems. The inference rules for the provers are described by conditional rewrite rules and their application is controlled by strategies. We show how different strategies using the same set of rewrite rules can yield different proof methods
