Under consideration for publication in J . Functional Programming 1 Container Types


A program derivation is said to be polytypic if some of its parameters are data types. Often these data types are container types, whose elements store data. Polytypic program derivations necessitate a general, non-inductive deenition of`container (data) type'. Here we propose such a deenition: a container type is a relator that has membership. It is shown… (More)