LTL

We consider here Linear Temporal Logic (LTL) formulas interpreted over finite traces. We denote this logic by LTLf. The existing approach for LTLfsatisfiability checking is based on a reduction to standard LTL satisfiability checking. We describe here a novel direct approach to LTLfsatisfiability checking, where we take advantage of the difference in the semantics between LTL and LTLf. While LTL satisfiability checking requires finding a fair cycle in an appropriate transition system, here we need to search only for a finite trace. This enables us to introduce specialized heuristics, where we also exploit recent progress in Boolean SAT solving. We have implemented our approach in a prototype tool and experiments show that our approach outperforms existing approaches.