ATN Program [file atn.clj]

• A global variable atnsent points to a list of words that remain in the input sentence:
  (GOOD CHINESE RESTAURANT IN LOS ALTOS)

• A global variable atnword points to the current word: GOOD

• (wordcat category ) tests whether atnword is in the specified category. It can also translate the word, e.g. (wordcat 'month) might return 3 if atnword is MARCH.

• (nextword) moves to the next word in the input

• (saveptr) saves the current sentence position on a stack, atnsavesent.

• (success) pops a saved position off the stack.

• (fail) restores a saved position from the stack (restoring atnsent and atnword) and returns nil.