Emil Post

Emil Post

An American-Polish mathematician who developed truth tables in 1921, independently of Wittgenstein, and later formulated Post canonical systems: sets of rewriting rules that transform strings of symbols into other strings. In 1936 he described a computational model equivalent to the Turing machine, arrived at independently. His production systems became the direct template for rule-based AI, where knowledge is encoded as condition-action rules and a program repeatedly matches and fires them, an architecture that runs through Newell and Simon's work and into the expert systems of the 1970s. (See also: Expert system, Allen Newell, Symbolic AI)