With the rapid growth of integration scale of VLSI chips and the present need for reliable computers in space exploration, fault diagnosis and fault toleran ce have become more important than before, and hence reveal a lot of interest ing topics which attract many researchers to make a great number of contribu tions to this field. In recent years, many new and significant results have been achieved. A quick scan over the proceedings of the conferences on fault tolerant computing and design automation as well as on testing will convince the reader of that. But unfortunately these achievements...