Making prophecies with decision predicates

We describe a new algorithm for proving temporal properties expressed in LTL of infinite-state programs. Our approach takes advantage of the fact that LTL properties can often be proved more efficiently using techniques usually associated with the branchingtime logic CTL than they can with native LTL algorithms. The caveat is that, in certain instances, nondeterminism in the system’s transition relation can cause CTL methods to report counterexamples that are spurious with respect to the original LTL formula. To address this problem we describe an algorithm that, as it attempts to apply CTL proof methods, finds and then removes problematic nondeterminism via an analysis on the potentially spurious counterexamples. Problematic nondeterminism is characterized using decision predicates, and removed using a partial, symbolic determinization procedure which introduces new prophecy variables to predict the future outcome of these choices. We demonstrate—using examples taken from the ...

• Type: Journal
• Year: 2011
• Where: POPL
• Authors: Byron Cook, Eric Koskinen
• Keywords: Linear Temporal Logic, LTL Properties, POPL 2011, Postgresql Database Server, Programming Languages