Re: strange behavior of subset
Jan Wielemaker <[email protected]>
| Newsgroups | gmane.comp.ai.prolog.swi |
|---|---|
| Message-ID | <[email protected]> |
On 01/07/2014 02:21 PM, db wrote: > Ok I found the problem : > > subset is based on membercheck that succeeds only once. Yes. It is one of these predicates that have been added to the library very long ago. The documentation already suggests it is not a logical predicate. You give a nice example. Cheers --- Jan > > Bye. > Dominique > > > Le 07/01/2014 14:17, db a �crit : >> Hello, >> >> I used swi prolog Multi-threaded, 64 bits, Version 7.1.4 >> under Ubuntu. >> >> I am suprise by the behavior of the subset predicate : >> >> >> ?- subset([p(A), q(A,B)], [p(1), p(2), q(2,3)]). >> false. >> >> >> ?- subset([p(A), q(A,B)], [p(2), p(1), q(2,3)]). >> A = 2, >> B = 3. >> >> Thus subset takes into account the order of the element >> in the sets, what is not expected when one deals with sets. >> Is is normal ? >> >> Thanks a lot >> >> Dominique >> >> >> >> _______________________________________________ >> SWI-Prolog mailing list >> [email protected] >> https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog >> >> !DSPAM:152,52cbff64251284767677671! >> > > _______________________________________________ > SWI-Prolog mailing list > [email protected] > https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog _______________________________________________ SWI-Prolog mailing list [email protected] https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog