Rule trees an execution mechanism for time-ordered forward deduction evaluating strategy of Starlog

Abstract

This is the second report on "Time-ordered Forward Deduction" algorithm for Starlog. A \fBRule Tree (R-tree)\fR structure is discussed. The R-tree is used to represent a program rule in the dynamic process of program execution. It serves not only as a structured data storage for program rules and their derivable instances, but also as a control structure in program execution which allows the execution to be carried out in more orderly and formal manner.