Experience with Predicate Abstraction

This reports some experiences with a recently-implemented prototype system for veriication using predicate abstraction, based on the method of Graf and Sa di 9]. Systems are described using a language of iterated guarded commands, called Mur ?? (since it is a simpliied version of our Mur protocol description language). The system makes use of two libraries: SVC 1] (an eecient decision procedure for quantiier-free rst-order logic) and the CMU BDD library. The use of these libraries increases the scope of problems that can be handled by predicate abstraction through increased eeciency, especially in SVC, which is typically called thousands of times. The veriication system also provides limited support for quantiiers in formulas. The system has been applied successfully to two nontrivial examples: the Flash multiprocessor cache coherence protocol, and a concurrent garbage collection algorithm. Ver-iication of the garbage collector algorithm required proving properties simple of graphs, which was also done using predicate abstraction.