<b_jonas> learn ayacc is ais523\'s yacc parser generator implementation, get it from (darcs clone http://nethack4.org/projects/ayacc) or a snapshot from "http://nethack4.org/pastebin/ayacc-2020-04.tar.gz".

Obvious, adj.: A postulate used to prove a wide variety of theorems too arduous to prove by other means. In American Sign Language, it is denoted by a vigorous waving of the hands.