Hyperedge replacement with rendezvous

Abstract

In this paper, we introduce and study a rendezvous mechanism for parallel replacements of hyperedges by (hyperedge-decorated) graphs that allows some merging of the replacing graphs if the attachment of the replaced hyperedges shares some nodes. The main result shows that the rendezvous mechanism can increase the generative power of table-controlled parallel hyperedge replacement graph grammars (which themselves are more powerful than ordinary hyperedge replacement graph grammars). 1.2 Definition (decorated graph) Let N be a set of nonterminal labels each element A of which is associated with a natural nmnber, its type, denoted by type(A).