From araizen@cs.huji.ac.il Fri Nov 08 03:16:09 2002 Received: with ECARTIS (v1.0.0; list lojban-list); Fri, 08 Nov 2002 03:16:09 -0800 (PST) Received: from mxout3.netvision.net.il ([194.90.9.24]) by digitalkingdom.org with esmtp (Exim 4.05) id 18A77K-0000TI-00 for lojban-list@lojban.org; Fri, 08 Nov 2002 03:16:06 -0800 Received: from default ([62.0.148.58]) by mxout3.netvision.net.il (iPlanet Messaging Server 5.2 HotFix 0.8 (built Jul 12 2002)) with SMTP id <0H590095S8LSCF@mxout3.netvision.net.il> for lojban-list@lojban.org; Fri, 08 Nov 2002 13:15:30 +0200 (IST) Date: Fri, 08 Nov 2002 13:15:58 +0200 From: Adam Raizen Subject: [lojban] standard logic To: "lojban-list@lojban.org" Message-id: <0H590095W8LTCF@mxout3.netvision.net.il> MIME-version: 1.0 X-Mailer: Foxmail 4.1 [eg] Content-Type: text/plain; charset=us-ascii X-archive-position: 2532 X-ecartis-version: Ecartis v1.0.0 Sender: lojban-list-bounce@lojban.org Errors-to: lojban-list-bounce@lojban.org X-original-sender: araizen@cs.huji.ac.il Precedence: bulk Reply-to: lojban-list@lojban.org X-list: lojban-list la pycyn cusku di'e >Strictly spaking, of course, what pc favors is taking {ro broda cu brode} , >with standard Lojban importing {ro} as basic and introducing the >non-importing form as >{ro da zo'u ganai da broda gi da brode}, as it normally is in Logic. and >The fact that your {ro} gives truth in the empty universe shows that it is >not the universal quantifier of standard logic, all of whose quantified >sentences are false in the empty universe. I think you need to distinguish between logic and Logic. Lojban is first and foremost the language of Logic, which is the theoretical framework which logicians use to develop logic, which is how logicians actually implement Logic. As has been noted, there are many different ways to choose your quantifiers, and many of them allow all the possibilities in one way or another. Lojban can potentially choose any of them, as long as what it chooses is self-consistent, and still be the language of Logic. Anyway, as I have already noted, it is possible in standard logic to have universal quantification give truth in the empty universe. Also, in modern standard logic, statements of the form "All P are S" are almost always automatically rewritten to the form "Ax(Px->Sx)", and very little is done with restricted quantification (and thus Lojban can certainly do the same). Plus, as you surely know, there are many, many logicians, and they are not inclined to agree on everything, so I think that it is highly disingenuous of you to claim that logic does it only one way, and all other ways are incompatible with Lojban calling itself [Ll]ogical. mu'o mi'e .adam.