Full abstraction for polymorphic π-calculus

The problem of finding a fully abstract model for the polymorphic π-calculus was stated in Pierce and Sangiorgi’s work in 1997 and has remained open since then. In this paper, we show that a variant of their language has a fully abstract model, which does not depend on type unification or logical relations. This is the first fully abstract model for a polymorphic concurrent language. In addition, we discuss the relationship between our work and Pierce and Sangiorgi’s, and show that their model based on type unification is sound but not complete.