Session-typed concurrent contracts

Abstract In sequential languages, dynamic contracts are usually expressed as boolean functions without externally observable effects, written within the language. We propose an analogous notion of concurrent for languages with session-typed message-passing concurrency. Concurrent partial identity processes that monitor bidirectional communication along channels and raise alarm if a contract is violated. in usual way must also satisfy transparency requirement, which guarantees terminating compliant programs observationally equivalent. illustrate several examples. show how to generate from refinement session-type system resulting monitors redundant can statically be seen well-typed.