Introducing CafeOBJ (1) : Formal Methods and CafeOBJ

Abstract

The formal method, or the method for writing and verifying formal specifications, with the CafeOBJ language system is described in a series of six tutorials. The CafeOBJ language is a most advanced formal specification language which extents the OBJ language, and behavioral, rewriting, and parameterized specifications can be written in it. The CafeOBJ language system can simulate equational reasoning by executing equations as rewrite rules, and be used as an interactive verification system.
This first tutorial presents an overview of the CafeOBJ formal method by using an example of “mutual exclusion protocol with a waiting queue” without getting into details of the language and the verification technique. In the following tutorials, the language and its semantics (2nd tutorial), equational reasoning and term rewriting systems (3rd tutorial) are presented, and the CafeOBJ's verification method with proof scores which only uses reductions (4th tutorial) is explained. Furthermore, CafeOBJ's verifications of an authentication protocol (5th tutorial) and a communication protocol (6th tutorial) are also presented, and several verification techniques are explained.