Type Specifications with Processes

                          Franz Puntigam
    Institut für Computersprachen, Technische Universität Wien
           Argentinierstraße 8, A-1040 Vienna, Austria
             E-mail: franz@complang.tuwien.ac.at

Object-oriented software development is characterized by the repeated
refinement of specifications and software components. The refinement of
specifications is facilitated by the use of specification languages which
support subtyping based on the principle of substitutability. In this
paper we propose to specify concurrent systems by types represented as
expressions of a process calculus. These types allow to specify also
dynamic language aspects and still support subtyping and static
type-checking.

Keywords: type specification, subtyping, static type checking,
          process calcul