The Semantics of Call-By-Value and Call-By-Name in a Nondeterministic Environment

Nondeterministic recursive procedures are considered in which parameters may be passed by use of call-by-value or one of two different formulations of call-by-name. These procedures are given an operational semantics via an evaluation mechanism. We define a denotational semantics using so-called nondeterministic domains, which are function spaces endowed with two partial orders. An operational characterization of equality of procedures under this denotational semantics is then given.