A general framework for typing graph rewriting systems is presented:
the idea is to statically derive a type graph from a given graph. In
contrast to the original graph, the type graph is invariant under
reduction, but still contains meaningful behaviour information. We
present conditions, a type system for graph rewriting should satisfy,
and a methodology for proving these conditions. In three case
studies it is shown how to incorporate existing type systems (for
the polyadic pi-calculus and for a concurrent object-oriented
calculus) and a new type system into the general framework.