Douglas B. Lenat

Prominent in artificial intelligence and machine learning research, Lenat was best known for the Cyc project, an attempt to build the basis of a general artificial intelligence by manually representing knowledge in the formal language CycL, based on extensions to first-order predicate calculus. The project was not without its critics, among them many members of the MIT hacker culture. It is perhaps for this reason that "bogosity" is jokingly said to be measured in microlenats according to the Jargon File, the lenat being considered too large for practical use.

In 1976 Lenat started teaching at Carnegie-Mellon and commenced his work on Eurisko, but returned to Stanford in a teaching role in 1978. His continuing work on Eurisko led to attention in 1982 from DARPA and MCC in Austin, Texas. In 1984 he left Stanford to commence work on Cyc, the fruits of which were spun out of MCC into Cycorp in 1994. In 1986, Lenat estimated the effort to complete Cyc would be 250,000 rules and 350 man-years of effort.