High-Level Multi-Threading in hProlog
  A new high-level interface to multi-threading in Prolog, implemented in hProlog, is described. Modern CPUs often contain multiple cores and through high-level multi-threading a programmer can leverage this power without having to worry about low-level details. Two common types of high-level explicit parallelism are discussed: independent and-parallelism and competitive or-parallelism. A new type of explicit parallelism, pipeline parallelism, is proposed. This new type can be used in certain cases where independent and-parallelism and competitive or-parallelism cannot be used. 
Timon Van Overveldt and Bart Demoen
cs.PL