On Global Types and Multi-Party Session

TL;DR

This paper introduces a new language for global types with trace-based semantics, ensuring soundness, completeness, and liveness in multi-party communication protocols, while discussing its limitations and comparing it with related languages.

Contribution

A streamlined global types language with trace semantics, providing soundness, completeness, and liveness guarantees for multi-party sessions, and offering a comparative analysis with existing languages.

Findings

Global types language with trace-based semantics

Multi-party sessions enjoy liveness, progress, and soundness

Completeness allows omission of redundant traces

Abstract

Global types are formal specifications that describe communication protocols in terms of their global interactions. We present a new, streamlined language of global types equipped with a trace-based semantics and whose features and restrictions are semantically justified. The multi-party sessions obtained projecting our global types enjoy a liveness property in addition to the traditional progress and are shown to be sound and complete with respect to the set of traces of the originating global type. Our notion of completeness is less demanding than the classical ones, allowing a multi-party session to leave out redundant traces from an underspecified global type. In addition to the technical content, we discuss some limitations of our language of global types and provide an extensive comparison with related specification languages adopted in different communities.