This volume contains the proceedings of the fIrst workshop held by the Theory and Formal Methods Section ofthe Imperial College Department of Computing. It contains papers from almost every member of the Section, from our long-term academic visitors, and from those who have recently left us. The papers fall into four broad areas: semantics concurrency logic specification with some papers spanning a number of disciplines. The subject material varies from work on mathematical foundations to practical applications of this theory, expressing the Section's commitment to both the foundations of...