MEM: A new execution model for Prolog

Abstract We present a new model for the execution of Prolog programs, called MEM (Multipath Execution Model), which is aimed at improving the performance of the standard sequential depth-first left-to-right execution model by reducing the computational cost of traversing the search tree associated to a program. The MEM model combines a depth and breadth exploration of the search tree that avoids the execution of several control instructions. Moreover, MEM can easily exploit a new kind of parallelism, called path parallelism, which allows the parallel execution of unify operations corresponding to different paths, with the additional benefit that parallel computations are always independent among them.