Definition of an Encapsulated Hierarchical Graph Data Model Static Aspects, Part 1

Graph grammars have been successfully used as a formalism for the specification of realistic problems but, as far as specification-in-the-large activities are concerned, they still have some deficiencies. In particular, most of them only support the use of flat graphs, whereas for certain applications hierarchical graphs would be a more suitable modelling tool. Furthermore, there is still the need for a graph grammar module concept that allows to split large specifications into smaller sub-specifications. We want to address this problem by applying object-oriented concepts to develop a hierarchical graph data model that supports a suitable module concept for graph grammars. In this paper, we present the first step in the definition of our encapsulated hierarchical graph (EHG) data model. We introduce the notion of EHG that supports complex nodes (i.e. nodes with an encapsulated graph as their content), edges, encapsulated graphs (i.e. graphs that support importing and exporting of node..