Abstract. In this paper, we describe the Cognitive Agents Specification Language (CASL), and exhibit its characteristics by using it to model the multiagent feature interaction resolution systemdescribedbyGriffeth and Velthuijsen[7]. We discuss the main features of CASL that make it a useful language for specifying and verifying multiagent systems. CASL has a nice mix of declarative and procedural elements with a formal semantics to facilitate the verification of properties of CASL specifications.