QPE
<language> 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].
