Random, Exhaustive and Symbolic Testing under One Roof

The new Quickcheck is a counterexample generator for Isa- belle/HOL that uncovers faulty specifications and invalid conjectures using various testing strategies. The previous Quickcheck only tested conjectures by random testing. The new Quickcheck extends the previous one and integrates two novel testing strategies: exhaustive testing with concrete values; and symbolic testing, evaluating conjectures with a nar- rowing strategy. Orthogonally to the strategies, we address two general issues: First, we extend the class of executable conjectures and specifica- tions, and second, we present techniques to deal with conditional conjec- tures, i.e., conjectures with premises. We evaluate the testing strategies and techniques on a number of specifications, functional data structures and a hotel key card system.