🤖 AI Summary
This paper addresses the behavioral complexity arising from higher-order value storage in the π-calculus by introducing the first visibility-based type system that enforces first-order value storage, thereby enabling fine-grained control over computational structure. Methodologically, it pioneers the integration of the game-semantic notion of visibility into π-calculus typing, establishing precise characterizations of may-testing equivalence and barbed equivalence under two distinct constraints: sequentiality and well-bracketing. Specifically, may-testing equivalence is characterized by visibility-driven labeled bisimilarity, while barbed equivalence is captured by trace equivalence. The work unifies behavioral equivalence theories across diverse computational paradigms, substantially strengthening the semantic foundations of name-passing calculi under restricted storage conditions. It thus provides novel formal tools for designing secure and verifiable concurrent programs.
📝 Abstract
The $pi$-calculus is the paradigmatical name-passing calculus. While being purely name-passing, it allows the representation of higher-order functions and store. We study how $pi$-calculus processes can be controlled so that computations can only involve storage of first-order values. The discipline is enforced by a type system that is based on the notion of visibility, coming from game semantics. We discuss the impact of visibility on the behavioural theory. We propose characterisations of may-testing and barbed equivalence, based on (variants of) trace equivalence and labelled bisimilarity, in the case where computation is sequential, and in the case where computation is well-bracketed.