The Syntax and Parsing of the Two-Dimensional Languages

This report introduces the idea of expressing programming concepts in a two-dimensional (pictorial) language. A specific two-dimensional language, Show and Tell, is briefly presented and formalisms that might be used to define the syntax of such a language are discussed. An abstraction of Show and Tell is defined, and a specific grammar formalism is presented for defining the syntax of this abstraction. The mechanisms found in expert systems are shown to be sufficient to parse languages defined by this formalism