Source : Free On-Line Dictionary of Computing

Guarded Horn Clauses
     
         (GHC) A parallel dialect of {Prolog} by K. Ueda in
        which each {clause} has a {guard}.  GHC is similar to
        {Parlog}.  When several clauses match a {goal}, their guards
        are evaluated in parallel and the first clause whose guard is
        found to be true is used and others are rejected.  It uses
        {committed-choice nondeterminism}.
     
        See also {FGHC}, {KL1}.
     
        (1995-05-09)