Cooperating Distributed Hyperedge Replacement Grammars

. The concept of cooperation and distribution as known from the area of grammar systems is introduced to graph grammars; more precisely, to hyperedge replacement (for short, HR) grammars. This can be seen as a modest approach to controlled HR. Two different derivation modes are considered, the so called t-mode and the =k-mode. For the t-mode it is shown that the class of hypergraph languages obtained is equal to the class of ET0L HR languages which is a natural generalization of the class of ET0L languages to hypergraphs. Keywords: graph grammar, grammar system, L-system 1. Introduction Cooperating grammar systems were introduced by Meersman and Rozenberg already in (Meersman and Rozenberg, 1978) in the context of two-level grammars. The systematic study of cooperating distributed (for short, CD) grammar systems was initiated by (Csuhaj-Varj'u and Dassow, 1990). Since then it has become a vivid field in computer science (see, e.g., (Csuhaj-Varj'u et al., 1994; Paun, 1995; Paun, 1998)..