constraints order
Michel Levy <[email protected]>
| Newsgroups | gmane.comp.gnu.prolog.general |
|---|---|
| Organization | LSR |
| Message-ID | <[email protected]> |
I do not understand why these two requests have different answers : | ?- X #\=Y, X #=Y. X = _#2(0..268435455) Y = _#21(0..268435455) | ?- X #=Y, X #\= Y. no. This contradicts the assumption that the order of the constraints is unimportant. Furthemore, in the official documentation, I read : fd_all_different(List) constrains all variables in List to take distinct values. This is equivalent to posting an inequality constraint for each pair of variables. But this equivalence is no true : | ?- X #=Y, fd_all_different([X,Y]). X = _#0(0..268435455) Y = _#0(0..268435455) yes Can you explain me the difference ? -- Michel Levy Laboratoire L.S.R., Bureau C214, B.P.72 - 38042 SAINT MARTIN D'HERES CEDEX e.mail : [email protected] tel :(33)476514022 http://www-lsr.imag.fr/users/Michel.Levy