Concurrent logic programming is a variant of logic programming deesigned for parallel computing in which programs are sets of guarded Horn clauses of the form: The conjunction G1, … , Gn is called the guard of the clause, and | is the commitment operator.
Later versions of concurrent logic programming include Ehud Shapiro's Concurrent Prolog and Ueda's Guarded Horn Clause language.
The development of concurrent logic programming was given an impetus when Guarded Horn Clause was used to implement KL1, the systems programming language of the Japanese Fifth Generation Project (FGCS).
The FGCS Project was a $400M initiative by Japan's Ministry of International Trade and Industry, begun in 1982, to use massively parallel computing/processing for artificial intelligence applications.
The choice of concurrent logic programming as the “missing link” between the hardware and the applications was influenced by a visit to the FGCS Project in 1982 by Ehud Shapiro, who invented Concurrent Prolog.