A timed contract-calculus

Abstract

Over these past years, formal reasoning about contracts between parties participating in a transaction has been increasingly explored in the literature. There has been a shift of view from that viewing contracts simply as properties to be satisfied by the parties to contracts as first class syntactic objects which can be reasoned about independently of the parties’ behaviour. In this paper, we present a contract calculus to reason about contracts abstracting the parties’ behaviour in a simulation relation. We study the contracts evolution in time by associating time constraints with deontic clauses, which allows to associate time limit with permissions, obligations and prohibitions. Then, we show how the calculus can be used to support the runtime monitoring of contracts and apply it to a plane boarding system case study.