A definitional constraint language for declarative parallel programming. Goffin systematically integratesequational constraints and functions within a uniform framework of concurrent programming. Goffin is an embedding of a functional language kernel (Haskell) into a layer of constraint logic, which allowslogical variables inside functional expressions. In order to preserve referential transparency, functional reductionsuspends until logical variables become bound. Logical variables are bound by equational constraints, which impose relations over expressions. Hence, constraints are the means to structure the concurrent reduction of functional expressions. (1995-02-21)