Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> comp.databases.theory -> Re: Counting propositions

Re: Counting propositions

From: x <x-false_at_yahoo.com>
Date: Fri, 18 Jun 2004 12:13:06 +0300
Message-ID: <40d2b121@post.usenet.com>

A related Prolog question.
Guess and then check what is the meaning of "s(X)" from the following Prolog clauses.

p(1).
p(2).
p(3).

s(X):-r(X,[]).

r(R,L):-q(X,L),r(R,[X|L]).
r(L,L).

q(X,L):-p(X), not(member(X,L)).

member(X,[X|_]).
member(X,[_|L]):-member(X,L).

It is possible to write a "pure" Prolog predicate that return the number of elements that make p(X) true ?
(without using findall, bagof, setof, assert, etc.)

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

Received on Fri Jun 18 2004 - 04:13:06 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US