QPE
1. A two-dimensional pictorial query language.
["Pictorial Information Systems", S.K. Chang et al eds, Springer 1980].
[Q-systems. A. Colmerauer, 1969].
2. 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].