Polyadic Pi-calculus based formal description and verification model for Web services

Type mismatch is a common error at Web service composition run-time,so a Web service formal description model based on polyadic Pi-calculus was built to avoid the error.The definition of basic type,grammar and verification rules were used to show the type goodness of single Web service,the operational semantics was used to show the type goodness of composition,and the replaceability of Web service was defined to explain how the function of Web service composition was verified.The typed formal description model proposed accurately explained the inexistence of type error in Web service composition run-time and the verification method of Web service composition.Finally,the example instructed that the effectiveness of all the definition and method proposed above.