A fully-abstract model for the /spl pi/-calculus

This paper provides both a fully abstract (domain-theoretic) model for the /spl pi/-calculus and a universal (set-theoretic) model for the finite /spl pi/-calculus with respect to strong late bisimulation and congruence. This is done by: considering categorical models, defining a metalanguage for these models, and translating the /spl pi/-calculus into the metalanguage. A technical novelty of our approach is an abstract proof of full abstraction: The result on full abstraction for the finite /spl pi/-calculus in the set-theoretic model is axiomatically extended to the whole /spl pi/-calculus with respect to the domain-theoretic interpretation. In this proof, a central role is played by the description of non-determinism as a free construction and by the equational theory of the metalanguage.