“…Horn Clauses, as an intermediate language, have become a popular formalism for verification [5,15], attracting both the logic programming and software verification communities [4]. As a result of these, several verification techniques and tools have been developed for CHCs, among others, [17,16,26,11,27,24,23]. To the best of our knowledge, the use of automata based approach for abstraction-refinement of Horn clauses is relatively new [27,33], though the original framework proposed for imperative programs goes back to [19,20].…”