Parsing graphs representing two dimensional figures

Generalized two dimensional context free grammars an extension of context free grammars to two dimensions, is described. This extension is a generalization of Tomita´s two dimensional context free grammars (M. Tomita, 1989), and better fits into the families of graph grammars described by Crimi (1990) Relation Grammars and by Flasinski (1988) edNLC Grammars, Figure Grammars are particularly useful for applications such as handwritten mathematical expressions. A two dimensional extension of the Cocke-Kasami-Younger parser for context-free languages is used to parse figures using these grammars