An attribute graph grammar for signal flow graphs

A signal flow graph grammar has been developed that generates signal flow graphs by means of subgraph rewriting. It includes some context-sensitive productions and is very concise. An attribute signal flow graph grammar has also been formalized as an extended grammar of the signal flow graph grammar, in order to formally define and evaluate a variety of information accompanying signal flow graphs. As a specific example of the attribute signal flow graph grammar, we formalized the attributes and semantic rules to extract the relationships of the signals running in signal flow graphs. A parser-evaluator that we have implemented on the basis of the formalized grammar evaluates the attribute values while it parses a diagram in a bottom-up parallel manner. This attribute signal flow graph grammar is expected to become the theoretical and practical foundation for supporting computerized system analysis and design by using signal flow graphs.