The CRITTER System: Analyzing Digital Circuits by Propagating Behavior and Specifications
Louis I. Steinberg, Van E. Kelly · 1982
CRITTER is a system that reasons about digital hardware designs, using a a declarative representation that can represent components and signals at arbitrary levels of abstraction. CRITTER can derive the behaviors of a component's outputs given the behaviors of the inputs, it can derive the specifications a component's inputs must meet in order for some given specifications on the outputs to be met, and it can verify that a given signal behavior satisfies a given specification. By combining these operations, it evaluates both the correctness and the robustness of the overall design.