Hello Vic.
On Aug 31, 2005, at 7:12 AM, Vic Bancroft wrote:
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
definitions !
The not/1 change seems to be a problem for people working from (poor)
textbooks. I guess a lot of textbooks must use not/1, although I think
the standards committee probably did the right thing by settling on
\+/1 instead. Perhaps gprolog (and others) could have some advisory
when not/1 is used: "use \+/1 instead, it's logically pure, or turn off
this advisory by setting the i_like_not flag to true."
[I think the biggest failure of the ISO definitions was not including
term_expansion and DCG. I consider these core features of a usable
Prolog system.]
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 ?
mp32compatibility.pl is part of the XGP source:
http://cvs.sourceforge.net/viewcvs.py/xgp/xgp/src/bridge/
mp32compatibility.pl
http://cvs.sourceforge.net/viewcvs.py/xgp/xgp/src/bridge/
mp32compatibility_ops.pl
It does not include a not/1 predicate though, since MP32 didn't use
that.
Cheers,
Lindsey
_______________________________________________
Users-prolog mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/users-prolog
