Lucent Technologies Inc.

Carlos Manuel Roman

Robert Paul Kurshan

Efficient formal verification of a system model is obtained by performing a state reachability analysis of an unrestricted full system model that includes constraints selected by the tester for testing a given property, followed by an analysis that permits a reduction in the complexity of the tested system's model. The analysis involves determining variables of the system's model that do not change value in the course of the state reachability analysis, often because of the constraints imposed prior to performing the reachability analysis. The unchanging variables are replaced with constants, and those constants are propagated through the system model to simplify the state transition relations that define the system. The simplified system model is then applied to a verification tool to determine whether the liveness property is satisfied.

Detecting of model errors through simplification of model via state reachability analysis

The invention presents a method and apparatus for forming a restricted model from a system model to reduce the computational resources required to formally verify the system design, without substantially reducing the ability to test all system model functions, or properties. In general, the restricted model is formed by restricting the range of assumable values of system model variables and system model inputs to a restricted set of values, based on the values assumed by the system model variables and system model inputs during a partial search of the system model. The restricted model can then be fully searched by a conventional verification tool to identify system design errors. Advantageously, the restricted model requires less computational resources to verify the system design (i.e. through a full search) than the original system model.

Method for detecting errors in models through restriction

The invention presents a method and apparatus for forming a restricted model from a system model to reduce the computational resources required to formally verify the system design, without substantially reducing the ability to test all system model functions, or properties. In general, the restricted model is formed by restricting the range of assumable values of system model variables and system model inputs to a restricted set of values, based on the values assumed by the system model variables and system model inputs during a partial search of the system model. The restricted model can then be fully searched by a conventional verification tool to identify system design errors. Advantageously, the restricted model requires less computational resources during a fall search than the original system model.

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Bethlehem, PA, United States of America

Carlos Manuel Roman