Path: utzoo!utgpu!watmath!clyde!mcdchg!chinet!att!ucbvax!hplabs!well!jax
From: jax@well.UUCP (Jack J. Woehr)
Newsgroups: comp.lang.prolog
Subject: Stupid Question about UNH Prolog
Summary: confused(jax) :- unh,!.
Keywords: UNH,cut,tarsiers
Message-ID: <7505@well.UUCP>
Date: 30 Oct 88 03:56:18 GMT
Reply-To: jax@well.UUCP (Jack J. Woehr)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 46

ok, forgive me for being stupid. In UNH Prolog, I consult the following:

/* cuttest.pro ... learning about the behaviour
   of the database and cuts.
*/

foo(1).
foo(2).
foo(3).

foobar(X,Y) :- foo(X),!,foo(Y).

	Then the query 

		?- foobar(X,Y).

	returns four answers;  (3,3) (3,1) (3,2) and (3,3)
in that order.

On the other hand, the file:

/* cuttest2.pro ... learning about the behaviour
   of the database and cuts.
*/

goobar(X,Y) :- goo(X),!,goo(Y).

goo(1).
goo(2).
goo(3).

	behaves as I expected the first one to do, returning three
answers: (1,1) (1,2) (1,3) to the query

	?- goobar(X,Y).

	Is UNH Prolog broken or am I?


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