Re: not()
Guido Leisker <[email protected]>
| Newsgroups | gmane.comp.gnu.prolog.bugs |
|---|---|
| Message-ID | <[email protected]> |
On Wed, 2007-05-02 at 09:47 +0100, Jasper Taylor wrote: > On Tuesday 01 May 2007 18:14:00 Guido Leisker wrote: > > I created a file test.pro: > > > > ---test.pro--- > > female(anita). > > male(X) :- not(female(X)). > > -------------- > > It is not a bug. The GNU-prolog manual does not mention a not() predicate. The > unary operator \+ does negation-by-failure, so your program should be: > > female(anita). > male(X) :- \+ female(X). > > Cheers > --Jasper > Oh, thank you very much! Guido