Verification by abstraction

Verification seeks to prove or refute putative properties of a given program. Deductive verification is carried out by constructing a proof that the program satisfies its specification, whereas model checking uses state exploration to find computations where the property fails. Model checking is largely automatic but is effective only for programs defined over small state spaces. Abstraction serves as a bridge between the more general deductive methods for program verification and the restricted but effective state exporation methods used in model checking. In verification by abstraction, deduction is used to construct a finite-state approximation of a program that preserves the property of interest. The resulting abstraction can be explored for offending computations through the use of model checking. We motivate the use of abstraction in verification and survey some of the recent advances.