From nobody@digitalkingdom.org Tue Jul 11 15:58:10 2006 Received: with ECARTIS (v1.0.0; list lojban-list); Tue, 11 Jul 2006 15:58:11 -0700 (PDT) Received: from nobody by chain.digitalkingdom.org with local (Exim 4.62) (envelope-from ) id 1G0RAt-0003JO-6v for lojban-list-real@lojban.org; Tue, 11 Jul 2006 15:57:51 -0700 Received: from rlpowell by chain.digitalkingdom.org with local (Exim 4.62) (envelope-from ) id 1G0RAs-0003JH-W3 for lojban-list@lojban.org; Tue, 11 Jul 2006 15:57:51 -0700 Date: Tue, 11 Jul 2006 15:57:50 -0700 To: lojban-list@lojban.org Subject: [lojban] Is Lojban a CFG? (was Re: [lojban-beginners] Re: Enumerating in Lojban) Message-ID: <20060711225750.GM10845@chain.digitalkingdom.org> Mail-Followup-To: lojban-list@lojban.org References: <925d17560607100826x2a37ffcfi69c9964cabf0b53@mail.gmail.com> <537d06d00607100919v70febc62u93929e72b0041c48@mail.gmail.com> <20060710164123.GS3440@chain.digitalkingdom.org> <20060710173540.GV3440@chain.digitalkingdom.org> <20060711052439.GC10845@chain.digitalkingdom.org> <20060711200739.GK10845@chain.digitalkingdom.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11+cvs20060403 From: Robin Lee Powell X-archive-position: 12124 X-ecartis-version: Ecartis v1.0.0 Sender: lojban-list-bounce@lojban.org Errors-to: lojban-list-bounce@lojban.org X-original-sender: rlpowell@digitalkingdom.org Precedence: bulk Reply-to: lojban-list@lojban.org X-list: lojban-list Moving this to the main list. I found most of it too technical for me to make much sense of; my CS degree is 10 years behind me these days. On Tue, Jul 11, 2006 at 05:34:30PM -0400, Jonathan Gibbons wrote: > >> then "le nu broda ku brode" and "le nu broda kei brode" are > >> grammatical, but "le nu broda brode", eliding both terminators, > >> is not. But if we rewrote the elidable terminators as optional > >> elements, then "le nu broda brode" would be grammatical and > >> ambiguous. > > > > I've read this at least three or four times already; given that > grammar and a general context-free language parser, rather than an > LALR(1) parser, it would find the derivation that splits "le nu > broda brode" into "(le nu broda) (brode)" by the start symbol, and > then "((LE) (NU broda)) (brode)" and so on, becuase with the > requirement of a sumti and a selbri, that statement is /not/ > ambiguous. It's actually a two-selbri requirement, not a sumti+selbri requirement. Try it with: le nu broda ku brode brodi le nu broda kei brode brodi le nu broda brode brodi Where should the last one break off the second selbri? Answer: no-where; it's simply not valid lojban, and no place is more valid than any other. There is no correct fix. > >Not to claim that this can be done in general (maybe it can, I > >don't know), I would like to point out that this particular > >example can easily be fixed by re-iterating the 'selbri' rule in > >sumti, with minor modifications: > > > > start = sumti selbri > > sumti = LE tanru /KU/ > > | LE NU tanru /KEI/ /KU/ > > | LE NU tanru /KU/ > > | LE NU tanru /KEI/ > > selbri = tanru | NU tanru /KEI/ > > tanru = BRIVLA | tanru BRIVLA > > > > That certainly does remove the (unambiguous given the previous > grammar) statement "le nu broda brode", if the elements in "/"s > are now required. Although it does look like there would need to > be an option under selbri for "NU tanru" by itself, to accept all > of the above statements. If, on the other hand, they are optional, > then it accepts the same language as the above. If they're a hack, > then they're still a hack. They were intended to be optional; I never tested this grammar that I can recall. > That said, I suspect this discussion may be outside the scope of > the beginners' list; would it be more polite to swap to a less > spam-everyone forum? Done. -Robin -- http://www.digitalkingdom.org/~rlpowell/ *** http://www.lojban.org/ Reason #237 To Learn Lojban: "Homonyms: Their Grate!" Proud Supporter of the Singularity Institute - http://singinst.org/ 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.