Linear Forwarders

Philippa Gardner, Cosimo Laneve, Lucian Wischik. In CONCUR 2003.


A linear forwarder is a processes which receives one message on a channel and sends it on a different channel. Such a process allows for a simple implementation of the asynchronous pi calculus, by means of a direct encoding of the pi calculus' input capability (i.e. where a received name is used as the subject of subsequent input). This encoding is fully abstract with respect to barbed congruence.

Linear forwarders are actually the basic mechanism of an earlier implementation of the pi calculus, the fusion machine. We modify the machine, replacing fusions by forwarders. The result is more robust in the presence of failures, and more fundamental.

  author = "Philippa Gardner and Cosimo Laneve and Lucian Wischik",
  title  = "Linear Forwarders",
  booktitle = "CONCUR 2003",
  year   = 2003,
  editor = "R. Amadio and D. Lugiez",
  volume = "2761",
  pages  = "415--430",
  series = "Lecture Notes in Computer Science",
  publisher = "Springer-Verlag",
  url    = "http:// lu/ research/ linfwd.html",


  • Full version in PDF format, 178k, 17 pages. Includes a proof that had to be ommitted from the conference proceedings.
  • Slides/handouts in PDF, 100k, 11 pages.
  • See also

  • The Fusion Machine - linear forwarders are basically a simplification of this fusion machine.