An important new phase in the study of parallel execution of logic programs is the development of efficient implementation techniques. This project focuses on the design of a virtual machine for the AND/OR Process Model, an abstract execution model in which user goals are solved by independent objects communicating via messages. This work can be characterized as an attempt to do for the AND/OR Process Model what the Warren Abstract Machine (WAM) did for Prolog: achieve significantly faster execution through compilation to a virtual machine tailored to the model of computation. Important aspects of a virtual machine for logic programs are the representation of binding environments and instructions that control the order in which goals are solved. The proposed machine will build what they call "closed environments," environments that have little or no interaction,so that they can be built and moved anywhere in a multiprocessor system. Minimal interaction between environments is important if the system will be implemented on a non-shared memory multiprocessor. The instruction set of the virtual machine will be tailored to operations of a new method for controlling AND-parallel processing.
