Graphical representation and execution animation for Prolog programs

GRASP (GRaphical Analysis System for Prolog) is a graphical environment for analyzing Prolog programs. A description is given of the ideas that enable GRASP to visualize the structure and control flow of Prolog programs. Two types of graphical representation for a Prolog program are proposed. They visualize program structure and the logical relations of predicates, and help the user to analyze a program statically. Execution animation on the graphical representations is proposed. It dynamically visualizes the control flow during execution of a program, and assists the user finding any unintended portions in the execution.