Verifying specifications is still one of the most important undeveloped reseach topics in software engineering. It is important because quite a few critical bugs are caused at the level of domains, requirements, and/or designs. It is also important for the cases where no program codes are generated and specifications are analyzed and verified only for justifying models of problems in real world.

This paper gives a survey of our research activities in verifying specifications with Proof Scores in CafeOBJ . After explaining fundamental issues and importance of verifying specifications, an overview of CafeOBJ language, the proof score approach in CafeOBJ including its applications to several areas are given.

This paper is based on our already published books or papers as [6, 12, 16], and refers to many of our related publications. Interested readers are invited to look into them.