Annegret Habel

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In this survey the concept of hyperedge replacement is presented as an elementary approach to graph and hypergraph generation. In particular, hyperedge replacement graph grammars are discussed as a (hyper)graph-grammatical counterpart to context-free string grammars. To cover a large part of the theory of hyperedge replacement, structural properties and(More)
We introduce the notions of nested constraints and application conditions, short nested conditions. For a category associated with a graphical representation such as graphs, conditions are a graphical and intuitive, yet precise formalism, well-suited to describe structural properties. We show that nested graph conditions are expressively equivalent to(More)
In each graph-grammar approach it is deened how and under which conditions graph productions can be applied to a given graph in order to obtain a derived graph. The conditions under which productions can be applied are called application conditions. Although the generative power of most of the known general graph-grammar approaches is suucient to generate(More)
The aim of this paper is to survey some recent trends in applied graph transformation as a rule based framework for the speciication and development of systems, languages, and tools. After recalling the basic features of graph transformation, we discuss a spectrum of applications including term graph rewriting, the speciication of the Agg-system, the(More)
In this paper we investigate and compare four variants of the double-pushout approach to graph transformation. As well as the traditional approach with arbitrary matching and injective right-hand morphisms, we consider three variations by employing injective matching and/or arbitrary right-hand morphisms in rules. We show that injective matching provides(More)