Stargazer: understanding the π-calculus, visually | Hacker News Reader

Stargazer: understanding the π-calculus, visually

emanueledosualdo.com

91 points1411313 comments

For those wondering about practical application, here's two quick examples on use with distributed, problem solving and web applications. They're both doing precise models with a focus on deadlock prevention.

http://www2.cs.siu.edu/~rahimi/papers/2.pdf

http://www.sersc.org/journals/IJGDC/vol8_no5/13.pdf

I love the pi calculus. It's a good starting point for analyzing distributed systems in a rigorous way. If you're interested in learning more about this kind of thing, check out the Kell calculus[0] and it's related calculi

[0] http://www-verimag.imag.fr/~bidinger/publi/fmoods2003.pdf

Also relevant: Pict [0], a π-calculus programming language.

[0]: http://www.cis.upenn.edu/~bcpierce/papers/pict/Html/Pict.htm...

For those of us who have never heard of pi calculus, can someone give a beginners description (wikipedia article just confused me even more)

The pi-calculus is a mathematical formalization of concurrent programs in the same way that lambda calculus is a formalization of computable functions. It is basically a notation that allows you to easily specify concurrent programs, and then rigorously reason about them.

"pi-calculus" would be a better term to use in the title, since the glyph used for pi looks like "n"

I just followed the guidelines when submitting - i.e:

> Otherwise please use the original title, unless it is misleading or linkbait.

It's regrettable that π looks similar to n, however I think it's a very minor issue that is resolved the second that you click the link.

Only if you use terrible fonts.

Anyone here knows a good self contained description?

https://en.wikipedia.org/wiki/%CE%A0-calculus

One of the links from that article : http://www.cs.tufts.edu/~nr/cs257/archive/jeannette-wing/pi....

There is also the Join calculus in case anyone is interested.

[0]: https://en.wikipedia.org/wiki/Join-calculus

In college I was fascinated by the Join calculus, in particular it's research implementation in Polyphonic C# and its successors.

This is awesome! Does it do anything like fdr or can it be plugged in to play traces demonstrating live/deadlock?

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