Prolog - History

History

The name Prolog was chosen by Philippe Roussel as an abbreviation for programmation en logique (French for programming in logic). It was created around 1972 by Alain Colmerauer with Philippe Roussel, based on Robert Kowalski's procedural interpretation of Horn clauses. It was motivated in part by the desire to reconcile the use of logic as a declarative knowledge representation language with the procedural representation of knowledge that was popular in North America in the late 1960s and early 1970s. According to Robert Kowalski, the first Prolog system was developed in 1972 by Alain Colmerauer and Phillipe Roussel. The first implementations of Prolog were interpreters, however, David H. D. Warren created the Warren Abstract Machine, an early and influential Prolog compiler which came to define the "Edinburgh Prolog" dialect which served as the basis for the syntax of most modern implementations.

Much of the modern development of Prolog came from the impetus of the Fifth Generation Computer Systems project (FGCS), which developed a variant of Prolog named Kernel Language for its first operating system.

Pure Prolog was originally restricted to the use of a resolution theorem prover with Horn clauses of the form:

H :- B₁, ..., B_n.

The application of the theorem-prover treats such clauses as procedures:

to show/solve H, show/solve B₁ and ... and B_n.

Pure Prolog was soon extended, however, to include negation as failure, in which negative conditions of the form not(B_i) are shown by trying and failing to solve the corresponding positive conditions B_i.

Subsequent extensions of Prolog by the original team introduced constraint logic programming abilities into the implementations.