Designing Equivalent Semantic Models for Process Creation

摘要

Operational and denotational semantic models are designed for languages with process creation, and the relationships between the two semantics are investigated. A uniform and static, a uniform and dynamic, a nonuniform and static, and a nonuniform and dynamic language are considered. The contrast between uniform and nonuniform is reflected in the use of linear time versus branching time models, the latter employing a version of Plotkin's resumptions. The operational semantics use Hennessy and Plotkin's transition systems. All models are built on metric structures, and involve continuations in an essential way. The languages studied are abstractions of the parallel object-oriented language POOL. The relationship between the two semantics for these abstractions is analyzed. A key role is played by an operator which decides dynamically whether it should act as sequential or parallel composition.