Multigenerative grammar systems are based on cooperating context-free grammatical components that simultaneously generate their strings in a rule-controlled or nonterminal-controlled rewriting way, and after this simultaneous generation is completed, all the generated terminal strings are combined together by some common string operations, such as concatenation, and placed into the generated languages of these systems. The present paper proves that these systems are equivalent with the matrix grammars. In addition, we demonstrate that these systems with any number of grammatical components can be transformed to equivalent two-component versions of these systems. The paper points out that if these systems work in the leftmost rewriting way, they are more powerful than the systems working in a general way.
multigenerative grammar systems, simultaneously controlled derivations, matrix grammars