Structuring the semantic definitions of graphical design notations

Although design notations are increasingly being given a formal semantics, often the notations are only informally related to their semantic models. This may be because graphical design notations cannot directly be given an abstract syntax using the well-studied string grammars. The paper proposes the use of node-labelled controlled graph grammars to define the abstract syntax of graphical design notations. To illustrate this approach, a simple 12-rule grammar is given for a subset of the MASCOT design notation