PROLOG

PROLOG was introduced in 1972. It was based on the predicate calculus and represented a new paradigm in programming languages-logic programming. PROLOG is used mainly in artificial intelligence research and is considered by some to be an attempt to create intelligent machines by moving away from imperative languages.

Source: "Concepts of Programming Languages" by Robert W. Sebesta, The Benjamin/Cummings Publishing Company, Inc, 1993