Towards synthesis from assume-guarantee contracts involving infinite theories: a preliminary report

A. Katis, M. Whalen, A. Gacek

FormaliSE 2016: FME Workshop on Formal Methods in Software Engineering, Austin, TX, USA, May 15, 2016

In previous work, we have introduced a contract-based realizability checking algorithm for assume-guarantee contracts involving infinite theories, such as linear integer/real arithmetic and uninterpreted functions over infinite domains. This algorithm can determine whether or not it is possible to construct a realization (i.e. an implementation) of an assume-guarantee contract. The algorithm is similar to k-induction model checking, but involves the use of quantifiers to determine implementability. While our work on realizability is inherently useful for virtual integration in determining whether it is possible for suppliers to build software that meets a contract, it also provides the foundations to solving the more challenging problem of component synthesis. In this paper, we provide an initial synthesis algorithm for assume-guarantee contracts involving infinite theories. To do so, we take advantage of our realizability checking procedure and a skolemization solver for forall-exists formulas, called AE-VAL. We show that it is possible to immediately adapt our existing algorithm towards synthesis by using this solver, using a demonstration example. We then discuss challenges towards creating a more robust synthesis algorithm.