Synthesizing LTL contracts from component libraries using rich counterexamples

Abstract

We provide a method to synthesize an LTL Assume/Guarantee (A/G) specification, or contract, as an interconnection of elements from a library, each of which is also represented by an LTL A/G contract. Our approach, based on counterexample-guided inductive synthesis, leverages an off-the-shelf model checker to reason about infinite-length counterexamples and guarantee correctness. To increase scalability, we also introduce a novel concept of specification decomposition, based on contract projections; we show how it can be used to break down our synthesis problem into several simpler tasks, without reducing the size of the solution space. We test our technique on three industry-relevant case studies.