From nobody@digitalkingdom.org Wed Jun 17 20:31:53 2009 Received: with ECARTIS (v1.0.0; list lojban-beginners); Wed, 17 Jun 2009 20:31:53 -0700 (PDT) Received: from nobody by chain.digitalkingdom.org with local (Exim 4.69) (envelope-from ) id 1MH8Lw-0000Gv-U1 for lojban-beginners-real@lojban.org; Wed, 17 Jun 2009 20:31:53 -0700 Received: from mail-px0-f192.google.com ([209.85.216.192]) by chain.digitalkingdom.org with esmtp (Exim 4.69) (envelope-from <00ai99@gmail.com>) id 1MH8Lu-0000GW-Am for lojban-beginners@lojban.org; Wed, 17 Jun 2009 20:31:52 -0700 Received: by pxi30 with SMTP id 30so431814pxi.28 for ; Wed, 17 Jun 2009 20:31:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=7DQLBFyLMw6ibr0d73mSh00RBBo8YL5VMGP0dLbR82s=; b=AQuJnrnMj8drT9cpty4Abg7Ks3R7KMLLfRYz+vnw5LPaplcpWabn4nf5v7sK3UHfpg 2SspEahfXwJ8uXW9jmFgEHS/MtTECNWRBTF3AIFFhQ/KqrZour8nQ3EDZGT5IqIzcZHT hasjECL7brmTV4lU3e37frNEjqWO7PwuTMqSA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=pqsxlD0NE5qRA8d9DM+s8nfNHxsgkVS6qozG/IEkAQJfFUa1kyooIR2b4U7vnRygHd 7ob83A3Z4EW0eVCj8f6aalz4RQ/rySVzhpSYLHdrlNYE36j/O9tbUTV4Lw12VRjgpWVc CD3tNbBjBQa0xcuTGpT9rxsjoFsOP+h/4DeLU= MIME-Version: 1.0 Received: by 10.143.41.5 with SMTP id t5mr853396wfj.134.1245295904549; Wed, 17 Jun 2009 20:31:44 -0700 (PDT) In-Reply-To: <20090618025832.GA15964@sdf.lonestar.org> References: <23f4e3390906171942q112fe172wccc403b91ba6001b@mail.gmail.com> <20090618025832.GA15964@sdf.lonestar.org> Date: Thu, 18 Jun 2009 13:01:44 +0930 Message-ID: <23f4e3390906172031i5d9cb450n837a63d776fd73b@mail.gmail.com> Subject: [lojban-beginners] Re: "djuno najo cusku" From: David Gowers <00ai99@gmail.com> To: lojban-beginners@lojban.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by Ecartis X-archive-position: 1850 X-ecartis-version: Ecartis v1.0.0 Sender: lojban-beginners-bounce@lojban.org Errors-to: lojban-beginners-bounce@lojban.org X-original-sender: 00ai99@gmail.com Precedence: bulk Reply-to: lojban-beginners@lojban.org X-list: lojban-beginners On Thu, Jun 18, 2009 at 12:28 PM, Minimiscience wrote: > .skamyxatra > > "{najo}" and "{jonai}" are essentially the same thing; "(NOT p) IFF q" is > logically equivalent to "p IFF (NOT q)", which are both equivalent to "p XOR > q." so P najo Q == (NOT p) IFF q? > > > of course you could also do the excessively verbose > > "djuno najo cusku .e cusku najo djuno" to express the idea. > > Two things: > > 1. The logical connectives for a given type of connection ({sumti}, {tanru}, >   etc.) all have the same precedence and are left-associative.  Thus, that >   utterance corresponds to "((djuno XOR cusku) AND cusku) XOR djuno)", which >   happens to simplify to "djuno OR cusku," i.e., "{djuno ja cusku}."  To get >   around this, either attach "{bo}" to each "{najo}" (technically, only the >   second one needs it, but attaching to both is better for symmetry), or put a >   "{ke}" after the "{.e}." > > 2. You're mixing a {tanru} connective ("{najo}") with a {sumti} connective >   ("{.e}") inside a {tanru}.  Either change the "{.e}" to "{je}" or otherwise >   reword the utterance (e.g., something like "{lonu djuno najo cusku .e lonu >   cusku najo djuno}"). Ah thanks, minimiscience. It looks like I just didn't understand IFF correctly. The truth table in http://en.wikipedia.org/wiki/If_and_only_if has helped there. So, 'djuno najo cusku' means 'not-know IFF say' ie the truth value for P is inverted so the truth table looks like P(djuno) Q(cusku) [P iff Q] F T T F F F T T F T F T Which is indeed XOR. Thanks! David