Russ Harmer CNRS/Université Paris-Diderot Title: Executable Knowledge Abstract: We will discuss the general concept of 'executable knowledge', with particular emphasis on its application to the study of signaling pathways in cell biology, and the specific approach of 'rule-based modeling' in Kappa. We will review the novel analyses -- notably the use of static analysis and causality -- of complex systems that this enables, but also consider the difficulties that arise and present some partial solutions to these. The discussion will be organized around the running example of the use of Kappa to model the erbB receptor network.