Abstract
GRAPHIX is a PASCAL based graph theory sub-language. It provides a set of graph theory algorithms, and allows the user to program directly in terms of graph structures theory algorithms, and allows the user to program directly in terms of graph structures with no knowledge of the internal representation of the graph. A preprocessor has been written to convert GRAPHIX/PASCAL programs into pure PASCAL. The main problems of a sub-language and preprocessing have been overcome in the design of the language and the preprocessor. An example of a GRAPHIX/PASCAL program is provided.