Transformation-Enabled Precondition Inference

Precondition inference is a non-trivial problem with important applications in program analysis and verification. We present novel iterative method for automatically deriving preconditions the safety unsafety of programs. Each iteration maintains over-approximations set safe unsafe initial states; which are used to partition program's states into those known be safe, unknown. then construct revised programs unknown iterate procedure until approximations disjoint or some termination criteria met. An experimental evaluation on software verification benchmarks shows that it can infer precise (sometimes optimal) not possible using previous methods.