Reordering of Prolog programs with AND-parallelism

A method that allows reordering of Prolog causes without reordering their solutions, called order tracking, is presented. Reordering clauses enables the execution of a program at lower cost, as well as more goals to be run in AND-parallel; order tracking ensures that the reordered clauses behave exactly like their originals. The Markov-chain model is extended for estimating probability and cost, adding order tracking and a model for AND-parallel execution. This allows for estimation of when reordering and AND-parallelism will speed execution and when they will slow it.<
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