Abstract: The amount of analysis performed in determining the validity of a property of a digital circuit is measured concurrent with performance of the analysis, and provided as an output when a true/false answer cannot be provided e.g. when stopped due to resource constraints. In some embodiments, a measure of value N indicates that a given property that is being checked will not be violated within a distance N from an initial state from which the analysis started. Therefore, in such embodiments, a measure of value N indicates that the analysis has implicitly or explicitly covered every possible excursion of length N from the initial state, and formally proved that no counter-example is possible within this length N.

Abstract: A computer is programmed in accordance with the invention to automatically analyze a digital circuit, to check if the digital circuit can enter a target state starting from a start state, by reusing information learned during a another analysis, checking if the same digital circuit can enter the same or different target state from a different start state. Use of learned information in accordance with the invention simplifies the analysis of the digital circuit (e.g. by allowing skipping one or more analysis acts). The learned information may be stored in a database. Depending on the embodiment, the two or more analyses may check on operation of the digital circuit for the same or different numbers of cycles.

Abstract: The amount of analysis performed in determining the validity of a property of a digital circuit is measured concurrent with performance of the analysis, and provided as an output when a true/false answer cannot be provided e.g. when stopped due to resource constraints. In some embodiments, a measure of value N indicates that a given property that is being checked will not be violated within a distance N from an initial state from which the analysis started. Therefore, in such embodiments, a measure of value N indicates that the analysis has implicitly or explicitly covered every possible excursion of length N from the initial state, and formally proved that no counter-example is possible within this length N.