The logic programming languages have clear semantics and embedded parallelism. And its evaluation is considered as a theorem proving or a inference process. Logic programs are constituted of the set of Horn clauses. A Guard Logic Language (GLL), evolutionary form of Horn clause, has many good features. In this paper, a parallel evaluator of GLL is implemented based on Conery's AND/OR Process Model.
The parallel evaluator consists of two parts; the front end is a compiler and the back end is a simulator. The compiler reads input logic programs, check syntactic errors and semantic errors, and generates internal representations of the logic programs to be read by the back end. The simulator reads the internal representations and simulates the parallel evaluation of the logic programs according to the AND/OR Process Model.
The simulator uses Woo and Choe's Redo Cause Set as a backtracking algorithm and employs Choe, Lee, and Woo's Affecting Set for the selective resetting.