Researched
Expert Systems
Programs with thousands of hand-written if-then rules diagnose and configure: the first commercial AI, which then stalls in the winter.
Open in the interactive tree →DENDRAL (1965) and MYCIN (1970s, blood infections) encoded expert knowledge as rules; XCON at DEC (from 1980) configured computer orders and saved millions. The effort of maintaining rules by hand and their brittleness outside their field led to the second AI winter in the late 1980s. The lesson: knowledge has to be learned, not written down.