This paper describes incremental logic synthesis for supporting function logic changes in the physical design stage of digital systems. The incremental logic synthesis is distinguished from logic synthesis in the respect that it updates only gate logic components, which must be changed due to the function logic changes, in the physically optimized gate logic structure. For making the incremental logic synthesis feasible, a gate logic structure identification and editing system has been developed with a corresponding gate matrix method as its core. This system has greatly contributed to the increase in design efficiency of the very large computer series M68XH.

A proper treatment of syntax and semantics in machine translation is introduced and discussed from the empirical viewpoint. For English-Japanese machine translation, the syntax directed approach is effective where the Heuristic Parsing Model (HPM) and the Syntactic Role System Play important roles. For Japanese-English translation, the semantics directed approach is powerful where the Conceptual Dependency Diagram (CDD) and the Augmented Case Marker System (which is a kind of Semantic Role System) play essential roles. Some examples of the difference between Japanese sentence structure and English sentence structure, which is vital to machine translation, are also discussed together with various interesting ambiguities.