MCMAS: A Model Checker for the Verification of Multi-Agent Systems. While temporal logic in its various forms has proven essential to reason about reactive systems, agent-based scenarios are typically specified by considering high-level agents attitudes. In particular, specification languages based on epistemic logic [7], or logics for knowledge, have proven useful in a variety of areas including robotics, security protocols, web-services, etc. For example, security specifications involving anonymity [4] are known to be naturally expressible in epistemic formalisms as they explicitly state the lack of different kinds of knowledge of the principals.