We define and implement a new procedure for automatically checking safety of infinite state systems in a modular way. The main idea is to infer universally quantified procedure summaries which suffice to show the safety property. We assume that the transition system can be modeled as a collection of (possibly mutually recursive) procedures, where the body of each procedure can be described using effectively propositional logic. Our analysis automatically infers universally quantified procedure summaries by using diagrams for generalizations from counterexamples to induction. It is implemented on top of a SAT solver. This procedure is a variant of IC3/PDR approach. We show that the procedure can be used to prove the absence of concurrent modification exceptions in Java programs.