Effective realization of recursive procedures in logic programs

The authors explore methodologies for effective realization of recursive procedures in logic programs. The effectiveness is achieved by reducing the number of context frames and interframe relations, through several related schemes. During programming or preprocessing, a subset of recursive procedures are transformed into ones that ensure the application of last call optimizations; the procedures can then be transformed into ones that allow multiple use, when desirable. During parallel interpretation, structured data are manipulated by a scheme that dynamically applies structure sharing or copying with little overhead. A communication scheme can then be used to realize transformed doubly recursive procedures. With these schemes the process structures of the transformed procedures coincide with the data structures of the procedures, and the transformed procedures achieve efficiencies up to an order of magnitude in time, space, and interprocess communication over the untransformed ones.<>