From araizen@newmail.net Thu Nov 07 08:30:55 2002 Return-Path: X-Sender: araizen@newmail.net X-Apparently-To: lojban@yahoogroups.com Received: (EGP: mail-8_2_3_0); 7 Nov 2002 16:30:55 -0000 Received: (qmail 3529 invoked from network); 7 Nov 2002 16:30:54 -0000 Received: from unknown (66.218.66.218) by m8.grp.scd.yahoo.com with QMQP; 7 Nov 2002 16:30:54 -0000 Received: from unknown (HELO n14.grp.scd.yahoo.com) (66.218.66.69) by mta3.grp.scd.yahoo.com with SMTP; 7 Nov 2002 16:30:54 -0000 Received: from [66.218.67.251] by n14.grp.scd.yahoo.com with NNFMP; 07 Nov 2002 16:30:54 -0000 Date: Thu, 07 Nov 2002 16:30:53 -0000 To: lojban@yahoogroups.com Subject: Re: importing ro Message-ID: In-Reply-To: User-Agent: eGroups-EW/0.82 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Length: 594 X-Mailer: Yahoo Groups Message Poster From: "Adam Raizen" X-Originating-IP: 62.0.146.101 X-Yahoo-Group-Post: member; u=3063669 X-Yahoo-Profile: araizen la .and. cusku di'e > 2. The universe is not empty. I don't accept this unless you add it as an axiom to your system. Note (from http://www.cgl.uwaterloo.ca/~wbcowan/teaching/cs24 6/s97/notes/lect07.html): "Instantiation: ForAll x: Px => There exists x: Px as long as the universe is not empty." and "Note the important role played by the empty universe. (ForAll x: Fx is true for any F if the universe is empty.)" So it's not obvious that the *only* possibility in logic is that AxFx -> ExFx on its own, without the additional postulate of a non-empty universe. mu'o mi'e .adam.