A Parallel Execution Model for Chronolog

Abstract

Chronolog(Z) is a logic programming language based on a linear-time temporal logic with unbounded past and future. By adding "choice predicates" to Chronolog(Z), it is possible to obtain exactly one answer to a given goal when we want to model dataflow style of stream-oriented computations. This paper, based on the framework we propose for exploiting parallelism in Chronolog, discusses and enhances the parallel execution model CHEM so that it is suitable for Chronolog(Z) programs with choice predicates. Dealing with the inherent context-parallelism in Chronolog programs, we propose the concept of parallel context-processes. We also introduce an intermediate virtual machine (CVM), which is granulated to exploit the argument parallelism through temporal unification. The details of the CVM instruction set are given in this paper. The use of a warehouse facility as an associate memory to store the results of previous computations is an important feature of this model. This paper..