Recognizing rooted context-free flowgraph languages in polynomial time

Abstract

We introduce context-free flowgraph grammars, which allow to replace single vertices together with their outgoing edges, thereby using the basic embedding idea of the algebraic graph grammar approach. For a naturally defined subclass of these, called the rooted grammars, an algorithm is presented which solves the language recognizing problem in time polynomial in the number of vertices of the input graphs.