Re: Storing data and code in a Db with LISP-like interface

From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Fri, 28 Apr 2006 00:44:11 +0200
Message-ID: <445148f8$0$31644$e4fe514c_at_news.xs4all.nl>

mAsterdam wrote:
> Neo wrote:

>>>> How do I express the following query in Prolog:
>>>> Find a person who likes a fruit and a vegetable.
>>>> (and (select person instance *)
>>>>       (select * like (and (select vegetable instance *)
>>>>                                 (select fruit instance *))))
>>>
>>>
>>> ?- person(P), likes(P, F), likes(P, V), fruit(F), vegetable(V).
>>
>> I actually expressed what I meant more clearly in the query then in
>> english which was ambigious :(  I meant find a person who likes
>> something that is both a vegetable and a fruit.

>
>
> ------------------
> ?- person(P), likes(P, Thing), likes(P, Thing), fruit(Thing),
> vegetable(Thing).
>
> P = john
> Thing = tomato1 ;
>
> No
> ------------------

That should have been:

---

?- person(P), likes(P, Thing), fruit(Thing), vegetable(Thing).

P = john
Thing = tomato1 ;

No

---

but fortunately the result is the same. There is one combination of P and Thing satisfying the query. (You can read "No" as 'no more solutions'). Received on Fri Apr 28 2006 - 00:44:11 CEST