VISUAL SPECIFICATIONS FOR TEMPORAL REASONING

Graphical interval logic (GIL) is a visual temporal logic in which formulas resemble the informal timing diagrams familiar to system designers and software engineers. It provides an intuitive and natural visual notation in which to express specifications for concurrent systems and retains the benefits of a formal notation. A visual editor permits GIL specifications to be easily constructed, and to be stored in and retrieved from files. The editor interfaces with a proof checker and model generator, which permit verification of temporal inferences. The paper shows how graphical specifications are created and used to reason about temporal properties of systems. It shows how pictures that formalize temporal arguments enhance understanding and help motivate successful proof strategies.