Pathway Logic is a step towards a vision of symbolic systems biology. It is an approach to modeling cellular processes based on formal methods. In particular, formal executable models of processes such as signal transduction, metabolic pathways, and immune system cell-cell signaling are developed using the rewriting logic language Maude and a variety of formal tools are used to query these models. An important objective of Pathway logic is to reflect the ways that biologists think about problems using informal models, and to provide bench biologists with tools for computing with and analyzing these models that are natural. In this paper we describe the Pathway Logic approach to the modeling and analysis of signal transduction, and the use of the Pathway Logic Assistant tool to browse and query these models. The Rac1 signaling pathway is used to illustrate the concepts.
Keywords: Pathway Logic, signal transduction, symbolic, formal executable model