QPE

Two-dimensional pictorial query language. "Pictorial

Information Systems", S.K. Chang et al eds, Springer 1980.

Q-systems. A. Colmerauer, 1969. A rewrite system with

one-way unification, used for English-French translation. It

led to Prolog. "The Birth of Prolog" A. Colmerauer et al,

SIGPLAN Notices 28(3):37-52 (March 1993).