Explainable Reactive Synthesis

Abstract

Reactive synthesis transforms a specification of a reactive system, given in a temporal logic, into an implementation. The main advantage of synthesis is that it is automatic. The main disadvantage is that the implementation is usually very difficult to understand. In this paper, we present a new synthesis process that explains the synthesized implementation to the user. The process starts with a simple version of the specification and a corresponding simple implementation. Then, desired properties are added one by one, and the corresponding transformations, repairing the implementation, are explained in terms of counterexample traces. We present SAT-based algorithms for the synthesis of repairs and explanations. The algorithms are evaluated on a range of examples including benchmarks taken from the SYNTCOMP competition.

Certifying DFA Bounds for Recognition and Separation

“…That is, we are given a DFA A and a bound k ≥ 1, and we seek a proof that L(A) is not k-DFA-recognizable. The need to accompany results of decision procedures by a certificate is not new, and includes certification of a "correct" decision of a model checker [14,22], reachability certificates in complex multi-agent systems [1], and explainable reactive synthesis [4]. Certifying that L(A) is not k-DFA-recognizable, we can point to k + 1 words h 1 , .…”

Certifying Inexpressibility

“…Our goal in this paper is to provide a simple and easy-to-understand explanation to inexpressibility results. The need to accompany results of decision procedures by an explanation (often termed "certificate") is not new, and includes certification of a "correct" decision of a model checker [24,44], reachability certificates in complex multiagent systems [1], and explainable reactive synthesis [4]. To the best of our knowledge, our work is the first to provide certification to inexpressibility results.…”