11 Finding All AnswersTop9 Assumables10 Negation-as-failure

10 Negation-as-failure

Negation as finite failure is implemented. Use ~G to mean the negation of expression G. G must be ground when ~G is called; this may be fixed in future implementations. The interaction of negation as failure and the depth-bound is handled correctly.

There is a problem with negation and why questions; sometimes the rule written out omits some negation symbols. This only occurs when non-atomic formulae are negated. The interaction of negation as failure with assumables isn't satisfactory. It is recommended that you don't use both assumables and negation as failure.


©David Poole, 1998

11 Finding All AnswersTop9 Assumables10 Negation-as-failure