Action Language is a specification language for reactive software systems. In this paper we present the Action Language Verifier which consists of 1) a compiler that converts Action Language specifications to composite symbolic representations, and 2) an infinite-state symbolic model checker which verifies (or falsifies) CTL properties of Action Language specifications. Our symbolic manipulator (Composite Symbolic Library) combines a BDD manipulator (for boolean and enumerated types) and a Presburger arithmetic manipulator (for integers) to handle multiple variable types. Since we allow unbounded integer variables, model checking queries become undecidable. We present several heuristics used by the Action Language Verifier to achieve convergence.