. The paper introduces a formal approach for the specification and verification of knowledge-based systems. We identify different elements of such a specification: a task definition, a problem-solving method, a domain model, an adapter, and assumptions that relate these elements. We present abstract data types and a variant of dynamic logic as formal means to specify these different elements. Based on our framework we can distinguish several verification tasks. In the paper, we discuss the application of the Karlsruhe Interactive Verifier (KIV) for this purpose. KIV was originally developed for the verification of procedural programs but it fits well for our approach. We illustrate the verification process with KIV and show how KIV can be used as an exploration tool that helps to detect assumptions necessary to close the gap between the task definition and the competence of a problemsolving method. 1 Introduction During the last years, several conceptual and formal specification tech...