Hierarchical Graph Transformation

Abstract

When graph transformation is used for programming purposes, large graphs should be structured in order to be comprehensible. In this paper, we present an approach for the rule-based transformation of hierarchically structured hypergraphs. In these graphs, distinguished hyperedges contain graphs that can be hierarchical again. Our framework extends the well-known double-pushout approach from flat to hierarchical graphs. In particular, we show how pushouts and pushout complements of hierarchical graphs and graph morphisms can be constructed recursively. Moreover, we make rules more expressive by introducing variables which allow us to copy and remove hierarchical subgraphs in a single rule application. © 2002 Elsevier Science (USA)

Hierarchical Models for Service-Oriented Systems

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“…The tuple N G , E G , t G , i G recalls the layered model of hierarchical graphs of [11], with i G being the function that embeds a graph (of a lower layer) inside an edge. Node sharing is introduced by the graph component F G and the renaming function r G , inspired by the graphs with (cospan-based) interfaces of [15].…”

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