必要平行最外归约策略

NEEDED PARALLEL-OUTERMOST REDUCTION STRATEGY

在必要集、必要位置等概念基础上，定义了必要平行最外归约策略．基于最小化必要集思想，该策略适用于正则系统全集，并接近按需调用策略的效率，在适用范围、效率和可实现性三个方面得到了兼顾．

Based on the concepts such as needed set, needed position and so on, needed parallel-outermost reduction strategy is introduced in this paper. By minimizing needed sets, this strategy is complete for the regular term rewriting systems, is efficient like call by need strategy, and can satisfy all demands of applicability, efficiency andcomputability.