Augmented transition network (ATN) grammars have, since their development by Woods [ 7; ~, become the most used method of describing grammars for natural language understanding end question answering systems. The advantages of the ATN notation have been su,naarized as "I) perspicuity, 2) generative power, 3) efficiency of representation, 4) the ability to capture linguistic regularities and generalities, and 5) efficiency of operation., [I , ]. The usual method of utilizing an ATN grammar in a natural language system is to provide an interpreter which can take any ATH graam~ar, a lexicon, and a sentence as data and produce.
