A Specification Logic for Termination Reasoning

We propose a logical framework for specifying and proving as sertions about program termination. Although termination of p rograms has been well studied, it is usually added as an external component to the specification logic. Here we propose to integrate termination requiremen ts directly into our specification logic, astemporal constraintsfor each phase of every method. Our temporal constraints can specify a strict decrease in a boun ded measure for termination proofs and the unreachability of method exit for nontermination proofs. Furthermore, our termination-infused logic can leverage r icher specification logics to help conduct more complex termination reasoning for p r grams with structural specification, heap manipulation, exception handlin g, and multiple phases. We expect our termination reasoning to directly benefit from any future improvements to our specification mechanism because it is fully inte grat d into our specification logic. Through an experimental evaluation, we rep ort on the usability and practicality of a verification system, based on separati on logic, that has been enhanced with our termination constraints.