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From: stefan@hpbbi4.BBN.HP.COM (#Stefan Bachert)
Newsgroups: comp.lang.prolog
Subject: Re: Having trouble with disjunction
Message-ID: <470016@hpbbi4.BBN.HP.COM>
Date: 15 Aug 90 14:03:44 GMT
References: <90226.091749F0O@psuvm.psu.edu>
Organization: Hewlett-Packard GmbH
Lines: 20

/ hpbbi4:comp.lang.prolog / F0O@psuvm.psu.edu /  3:17 pm  Aug 14, 1990 /

Watch the precedence. I added brackets to show you what you
told your prolog.


         gofirst(Player) :-
         (   random(RandNum),
             RandNum < 0.5, Player = computer );
         (   RandNum >= 0.5, Player = opponent).

I think you intended the following 

         gofirst(Player) :-
             random(RandNum),
            (RandNum < 0.5, Player = computer ;
             RandNum >= 0.5, Player = opponent).


Stefan