An Enhancement to Graph Grammar for the Specification of Edge Semantics

Graph grammar is a two-dimensional formal method, providing an intuitive yet formal tool for graphical models. However, existing graph grammar formalisms either ignore the specification of edge semantics or lack the parsing ability. To handle these problems, this paper improves the edge processing of graph grammar by introducing curvatures and bend-directions into the formalism of graph grammar. With an entire update of the theoretical framework and grammatical operations, the expressive power and application scope of graph grammar are both increased. Moreover, an example on simple pattern design is given to illustrate the application of the improved formalism.