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]. (2003-12-25)