Graphical representation of logic programs and their behaviour

The paper describes a set of graphs that form a coherent framework for the design and implementation of a graphical environment for logic programming. The set includes three types of graphs which collectively represent the structure of logic programs and their behavior. The representational formalism underlying the development of these graphs is based on cyclic AND/OR graphs. One of the most important properties of the representation scheme presented is the ease with which the program behavior can be mapped onto the source code. This is accomplished by folding the graph that represents program behavior onto the graph that represents the source code. In the representation scheme, information regarding the generation of values for variables is represented using a separate set of binding dependency graphs which are particularly useful in debugging