From nobody@digitalkingdom.org Wed Oct 29 03:28:10 2008 Received: with ECARTIS (v1.0.0; list lojban-list); Wed, 29 Oct 2008 03:28:10 -0700 (PDT) Received: from nobody by chain.digitalkingdom.org with local (Exim 4.69) (envelope-from ) id 1Kv8Ha-0005TC-50 for lojban-list-real@lojban.org; Wed, 29 Oct 2008 03:28:10 -0700 Received: from kcout02.prserv.net ([12.154.55.32]) by chain.digitalkingdom.org with esmtp (Exim 4.69) (envelope-from ) id 1Kv8HW-0005Sq-Ua for lojban-list@lojban.org; Wed, 29 Oct 2008 03:28:10 -0700 Received: from [192.168.0.6] (cpe-67-242-12-135.twcny.res.rr.com[67.242.12.135]) by prserv.net (kcout02) with SMTP id <20081029102755202009f5tfe> (Authid: usinet.kpreid); Wed, 29 Oct 2008 10:28:00 +0000 X-Originating-IP: [67.242.12.135] Message-Id: <44620A63-76DB-4D3A-BAB7-0A8E6D4AEAFC@mac.com> From: Kevin Reid To: lojban-list@lojban.org In-Reply-To: <20081029013224.GO26657@digitalkingdom.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed; delsp=yes Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by Ecartis Mime-Version: 1.0 (Apple Message framework v929.2) Subject: [lojban] Re: [llg-members] Re: Re: A challenge for computer science/programming geeks: The LLG wants to give you $500! Date: Wed, 29 Oct 2008 06:27:51 -0400 References: <20081028215134.GK31434@digitalkingdom.org> <925d17560810281730t6ab2f3c3i860e7b086de5aa4c@mail.gmail.com> <20081029005927.GH26657@digitalkingdom.org> <925d17560810281820m5bf3844ey27fd29da6e44a716@mail.gmail.com> <20081029012419.GM26657@digitalkingdom.org> <925d17560810281830h2b491a81s5b128a59561963c1@mail.gmail.com> <20081029013224.GO26657@digitalkingdom.org> X-Mailer: Apple Mail (2.929.2) X-Spam-Score: 0.7 X-Spam-Score-Int: 7 X-Spam-Bar: / X-archive-position: 14878 X-ecartis-version: Ecartis v1.0.0 Sender: lojban-list-bounce@lojban.org Errors-to: lojban-list-bounce@lojban.org X-original-sender: kpreid@mac.com Precedence: bulk Reply-to: lojban-list@lojban.org X-list: lojban-list On Oct 28, 2008, at 21:32, Robin Lee Powell wrote: > On Tue, Oct 28, 2008 at 10:30:16PM -0300, Jorge Llambías wrote: >> On Tue, Oct 28, 2008 at 10:24 PM, Robin Lee Powell >> wrote: >>> >>> I don't believe, but am not certain, that that is possible. >>> That is, I believe that if there is more than one way to >>> generate a string, you've describe an ambiguous language, and >>> that such a description would not, in fact, describe Lojban. >> >> See example 3 in >> > > You win. It seems to me that if you have such an ambiguous grammar, then it is, if not actually wrong, then misleading: the parse tree has degrees of freedom which are not actually part of the structure of the language. For example, the trivial grammar SELBRI -> BRIVLA | SELBRI SELBRI will generate only valid selbri, but non-left-leaning 'parse' trees may suggest tanru structure which isn't actually present (due to lack of ke...ke'e). (On the other hand, you can have an unambiguous grammar whose trees go the wrong direction; e.g. right-associative tanru.) (An unambiguous grammar for the same set of strings would be SELBRI -> BRIVLA | SELBRI BRIVLA An unambiguous grammar for the same set of parse trees would be SELBRI -> SBATOM | SELBRI SBATOM SBATOM -> BRIVLA | "ke" SELBRI "ke'e" ) -- Kevin Reid To unsubscribe from this list, send mail to lojban-list-request@lojban.org with the subject unsubscribe, or go to http://www.lojban.org/lsg2/, or if you're really stuck, send mail to secretary@lojban.org for help.