Temporal Reasoning for Procedural Programs

While temporal verification of programs is a topic with a long history, its traditional basis—semantics based on word languages—is ill-suited for modular reasoning about procedural programs. We address this issue by defining the semantics of procedural (potentially recursive) programs using languages of nested words and developing a framework for temporal reasoning around it. This generalization has two benefits. First, this style of reasoning naturally unifies Manna-Pnueli-style temporal reasoning with Hoare-style reasoning about structured programs. Second, it allows verification of "non-regular" properties of specific procedural contexts—e.g., "If a lock is acquired in a context, then it is released in the same context." We present proof rules for a variety of properties such as local safety, local response, and staircase reactivity; our rules are sufficient to prove all temporal properties over nested words. We show that our rules are sound and relatively complete. Disciplines Computer Sciences Comments From the 11th International Conference, VMCAI 2010, Madrid, Spain, January 17-19, 2010. This conference paper is available at ScholarlyCommons: http://repository.upenn.edu/cis_papers/543 Temporal Reasoning for Procedural Programs ? Rajeev Alur and Swarat Chaudhuri 1 University of Pennsylvania, USA 2 Pennsylvania State University, USA Abstract. While temporal verification of programs is a topic with a long While temporal verification of programs is a topic with a long history, its traditional basis—semantics based on word languages—is illsuited for modular reasoning about procedural programs. We address this issue by defining the semantics of procedural (potentially recursive) programs using languages of nested words and developing a framework for temporal reasoning around it. This generalization has two benefits. First, this style of reasoning naturally unifies Manna-Pnueli-style temporal reasoning with Hoare-style reasoning about structured programs. Second, it allows verification of “non-regular” properties of specific procedural contexts—e.g., “If a lock is acquired in a context, then it is released in the same context.” We present proof rules for a variety of properties such as local safety, local response, and staircase reactivity; our rules are sufficient to prove all temporal properties over nested words. We show that our rules are sound and relatively complete.