Speculative parallelism in a distributed graph reduction machine

A scheme for adding speculative evaluation to the distributed implementation of a lazy functional language is presented. The scheme assigns reduced scheduling priorities to speculative computations to prevent them from overwhelming processing resources or altering the program´s semantics. Scheduling priorities are dynamically adjusted during execution as speculative computations are found to be needed. By terminating computations associated with reclaimed pieces of graph, a distributed reference counting algorithm can be used to reclaim garbage nodes and to detect and terminate computations that are not required. A scheduling scheme and load balancing that operate in the presence of prioritised computations are briefly presented