A Chart Semantics for the Pi-Calculus
2008 (English)In: Electronical Notes in Theoretical Computer Science, ISSN 1571-0661, Vol. 194, no 2, 3-29 p.Article in journal (Refereed) Published
We present a graphical semantics for the pi-calculus, that is easier to visualize and better suited to expressing causality and temporal properties than conventional relational semantics. A pi-chart is a finite directed acyclic graph recording a computation in the pi-calculus. Each node represents a process, and each edge either represents a computation step, or a message-passing interaction. Pi-charts enjoy a natural pictorial representation, akin to message sequence charts, in which vertical edges represent control flow and horizontal edges represent data flow based on message passing. A pi-chart represents a single computation starting from its top (the nodes with no ancestors) to its bottom (the nodes with no descendants). Unlike conventional reductions or transitions, the edges in a pi-chart induce ancestry and other causal relations on processes. We give both compositional and operational definitions of pi-charts, and illustrate the additional expressivity afforded by the chart semantics via a series of examples.
Place, publisher, year, edition, pages
2008. Vol. 194, no 2, 3-29 p.
pi-calculus; causality; message sequence charts
IdentifiersURN: urn:nbn:se:uu:diva-161489DOI: 10.1016/j.entcs.2007.11.002OAI: oai:DiVA.org:uu-161489DiVA: diva2:456297
EXPRESS 2007, 14th International Workshop on Expressiveness in Concurrency, September 3, Lisbon, Portugal