Towards a Verification Framework for Haskell by Combining Graph Transformation Units and SAT Solving

The development of correct software systems is of highest relevance in software engineering. Various methods have been applied to gain this goal like theorem provers, exhaustive tests, or algebraic specification techniques. In this paper, we propose a new approach for the automatic verification of Haskell programs by combining graph transformation units and SAT solving. Therefor, function equations, known properties, and the property to be proven are translated into graph transformation units for the base case and the inductive step. These units perform a structural induction to verify the property. In general, the automation of this process is highly nondeterministic because in each rewriting step severals rules could be applied, also those that may lead in the wrong direction. To tackle this deficiency we translate the derivation process of graph transformation into propositional formulas and yield, in this way, the whole state space up to a certain bound.