1. Amplitude Modulation. 2. A program by Doug Lenat to discover concepts in elementary mathematics. AM was written in 1976 in Interlisp. From 100 fundamental concepts and about 250 heuristics it discovered several important mathematical concepts including subsets, disjoint sets, sets with the same number of elements, and numbers. It worked by filling slots in frames maintaining an agenda of resource-limited prioritised tasks. AM' s successor was Eurisko. . (1999-04-19)