Re: problems with not and unasserted facts

Vic Bancroft <[email protected]> Wed, 31 Aug 2005 07:13:18 -0400

Newsgroups	gmane.comp.gnu.prolog.general
Message-ID	<[email protected]>

Lindsey Spratt wrote:

> not/1 is not a built-in in gprolog. Instead, use \+ / 1. 

This seems to be the most common issue introduced by the ISO prolog 
definitions !

> You could define a not/1 predicate as:
>
> not(Goal) :-
>     \+ call(Goal).
>
Hey Lindsey, don't you have a compatibility library of predicates around 
somewhere ?

more,
l8r,
v