He got his Doctor of Philosophy (Ph.D.) from the Massachusetts Institute of Technology (MIT) in 1962, under Hartley Rogers with a thesis on computability.
[1] With John McCarthy, in the late 1950s and early 1960s, he helped produce the earliest implementations of the programming language Lisp,[2] and under Marvin Minsky he did early research on visual pattern recognition in Lisp.
[3][4][5] He is also credited by some with the idea, and an initial implementation, of logic programming.
[1][6][7][8] In 1966 he moved into cancer-related research, specifically at National Institutes of Health and later the National Cancer Institute where he turned his interest in visual pattern recognition to medical imaging applications.
[1][10][11][12][13][14] His work on models of clustering for chemical compounds was pronounced a "milestone" by the Developmental Therapeutics Program of the National Cancer Institute, for "revolutioniz[ing] the selection of compounds of interest by measuring the novelty of a chemical structure by comparing it to known compounds.