Re: beginner question (SOLVED)
Luca Ciciriello <[email protected]>
| Newsgroups | gmane.comp.gnu.prolog.general |
|---|---|
| Message-ID | <[email protected]> |
Yes, you are right. I haven't noticed the warning. I've made contiguous the statements. All solved. Thanks. Luca. On May 9, 2010, at 5:54 PM, Sylvain Soliman wrote: > * Luca Ciciriello <[email protected]>: >> I've created the file test2.pl with the following content: >> >> listensToMusic(mia). >> happy(yolanda). >> playsAirGuitar(mia) :- listensToMusic(mia). >> playsAirGuitar(yolanda) :- listensToMusic(yolanda). >> listensToMusic(yolanda):- happy(yolanda). >> >> and I've loaded it in to interpreter typing [test2]. > > And you have seen a warning message: > "test2.pl:5: warning: discontiguous predicate listensToMusic/1 - clause > ignored" > >> now the book is telling me that if I type at the prompt the query: >> >> ?- playsAirGuitar(yolanda). >> >> the result i obtain is "yes". >> >> My problem is that the result I obtain is a big "no". >> >> Now, as student, I'm a bit confused. >> Who is right and who is wrong? >> The book or the interpreter? > > Hmmm... both! > > GNU Prolog does not allow discontiguous predicates (and told you so!), so > "no" is correct... However the book is correct "in general", and if you > make the two clauses of listenToMusic contiguous (just one after the other) > it will work. > > Best, > > Sylvain. > > -- > Sylvain Soliman <[email protected]> Tel: (+33) 1 39635761 > INRIA Paris-Rocquencourt - Equipe CONTRAINTES Fax: (+33) 1 39635469 > Domaine de Voluceau, Rocquencourt, BP 105 GnuPG Public Key: 0x0F53AF99 > 78153 LE CHESNAY CEDEX - FRANCE http://contraintes.inria.fr/~soliman/ > _______________________________________________ > Users-prolog mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/users-prolog