Computing protected circumscription

Jack Minker, Donald Perlis
1985 The Journal of Logic Programming  
T his paper deals with computing circumscription in the case of Horn data with additional protection (indefinite data), an intermediate investigation between Reiter'sr esult on predicate completion and Lifschitz'se fforts to makeg eneral (formula) circumscription more efficient as a computational tool. Reiter has shown a close tie between McCarthy'sc ircumscription and Clark'sp redicate completion. Here we investigate a similar tie between an extended version of circumscription involving
more » ... ed data, and an extended version of predicate completion. When we have a fully ground atomic protected theory,w eshow that an extension to the relational algebra can be used to obtain all (and only) correct answers. When general Horn axioms are added to the protected theory,weshowthat Horn axioms also can be used to compute sound answers; however, some correct answers will not be found.
doi:10.1016/s0743-1066(85)80002-9 fatcat:pcspjcihtvcybdkayh6f2fm5ji