Pict correctness revisited

The Pict programming language is an implementation of the π-calculus in which executions of π-calculus terms are specified via an abstract machine. An important property of any concurrent programming language implementation is the fair execution of threads. After defining fairness for the π-calculus, we show that Pict abstract machine executions implement fair π-calculus executions. We also give new proofs of soundness and liveness for the Pict abstract machine.