An extralogical feature of Prolog and other {logic programming} languages in which failure of {unification} is treated as establishing the negation of a relation. For example, if Ronald Reagan is not in our database and we asked if he was an American, Prolog would answer "no". (1994-11-29)

In addition suitable contents:
[ 2 ] [ = ] [ ag ] [ ai ] [ al ] [ am ] [ an ] [ ar ] [ arc ] [ as ] [ at ] [ b ] [ ba ] [ base ] [ ca ] [ cat ] [ ch ] [ data ] [ database ] [ du ] [ ed ] [ eg ] [ er ] [ es ] [ failure ] [ feature ] [ fi ] [ file ] [ ga ] [ ge ] [ gi ] [ gr ] [ gu ] [ h ] [ hing ] [ hr ] [ id ] [ il ] [ in ] [ io ] [ is ] [ ke ] [ la ] [ language ] [ ld ] [ Lex ] [ li ] [ logical ] [ logic programming ] [ lu ] [ mm ] [ mo ] [ mod ] [ module ] [ mp ] [ na ] [ ne ] [ ng ] [ ni ] [ no ] [ ns ] [ ph ] [ pl ] [ pr ] [ program ] [ programming ] [ Prolog ] [ query ] [ rc ] [ re ] [ relation ] [ ro ] [ se ] [ sh ] [ sk ] [ st ] [ th ] [ tr ] [ ua ] [ unification ]