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[87.194.76.177]) by mx.google.com with ESMTPS id u47sm7869708eeo.9.2012.08.14.08.48.28 (version=SSLv3 cipher=OTHER); Tue, 14 Aug 2012 08:48:29 -0700 (PDT) Message-ID: <502A734B.1060906@gmail.com> Date: Tue, 14 Aug 2012 16:48:27 +0100 From: And Rosta User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.28) Gecko/20120306 Thunderbird/3.1.20 MIME-Version: 1.0 To: lojban@googlegroups.com Subject: Re: [lojban] &Lang References: <90a7e54c-42fe-4ee0-9693-8155db9a7646@googlegroups.com> <4FFDC7C8.2010707@gmail.com> <237c4ac5-64f3-40fa-81d3-8a97c76dcc5d@googlegroups.com> <1342109844.79789.YahooMailNeo@web184407.mail.bf1.yahoo.com> <4FFF180C.8060000@gmail.com> <4FFF534B.9010509@gmail.com> <5000314E.10906@gmail.com> In-Reply-To: X-Original-Sender: and.rosta@gmail.com X-Original-Authentication-Results: gmr-mx.google.com; spf=pass (google.com: domain of and.rosta@gmail.com designates 209.85.215.177 as permitted sender) smtp.mail=and.rosta@gmail.com; dkim=pass header.i=@gmail.com Reply-To: lojban@googlegroups.com Precedence: list Mailing-list: list lojban@googlegroups.com; contact lojban+owners@googlegroups.com List-ID: X-Google-Group-Id: 1004133512417 List-Post: , List-Help: , List-Archive: Sender: lojban@googlegroups.com List-Subscribe: , List-Unsubscribe: , Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-Spam-Score: -0.7 (/) X-Spam_score: -0.7 X-Spam_score_int: -6 X-Spam_bar: / .arpis., On 13/07/2012 19:05: > On Fri, Jul 13, 2012 at 10:31 AM, And Rosta > wrote: > An example (without wanting to be distracted by irrelevant details): > > "Da djuno lo du'u de prami da gi'e de nelci da" > djuno(da, &(prami(de, da), nelci(de, da))) > > Task 1: notate this (linearly) so that "da" and "de" each appear only= once. > > And then: > > Task 2: Improve the system so that speakers don't have to hold in mem= ory the arbitrary correspondence between variable & phonological form. > > Will De Bruijn indices deal with Task 1? If they do, I'd be thrilled = to have learnt summat new. > > > Ah... No. De Bruijn indices do nothing about factoring out common use sit= es. You might want to look into the SKI (or SK) calculus; it is capable of = expressing everything that the lambda calculus is. > > What you really want is to define a predicate out of djuno, du'u, prami, = and nelci that has the right meaning and never use "da" or "de" at all, bec= ause if they appear only once and in obvious positions, they are superfluou= s. > > Here's how I would go about deriving such a predicate, in case it helps: > > Recognize that \ko'a. \ko'e. gi'e (prami ko'a ko'e) (nelci ko'a ko'e) is = a useful abstraction > This abstraction can be generalized to > \conn. \b1. \b2. \ko'a. \ko'e. conn (b1 ko'a ko'e) (b2 ko'a ko'e) which r= educes to SK as follows > \conn. \b1. \b2. \ko'a. \ko'e. (conn (b1 ko'a ko'e)) = (b2 ko'a ko'e) > \conn. \b1. \b2. \ko'a. S (\ko'e. conn (b1 ko'a ko'e)) = (\ko'e. (b2 ko'a) ko'e) > \conn. \b1. \b2. \ko'a. S (S (\ko'e. conn) (\ko'e. (b1 ko'a) ko'e)) = (b2 ko'a) > \conn. \b1. \b2. \ko'a. S (S (K conn) (b1 ko'a)) = (b2 ko'a) > > \conn. \b1. \b2. \ko'a. (S (S (K conn) (b1 ko'a))) = (b2 ko'a) > \conn. \b1. \b2. S (\ko'a. S (S (K conn) (b1 ko'a))) (\ko= 'a. b2 ko'a) > \conn. \b1. \b2. S (S (\ko'a. S) (\ko'a. S (K conn) (b1 ko'a))) = b2 > \conn. \b1. \b2. S (S S (S (\ko'a. S (K conn)) (\ko'a. b1 ko'a))) = b2 > \conn. \b1. \b2. S (S S (S (S (\ko'a. S) (\ko'a. K conn)) b1)) = b2 > \conn. \b1. \b2. S (S S S S S (K conn) b1) b2 > > And now I'm bored, but I think that this was illustrative. Either I've misunderstood your response, or you've misunderstood the challe= nge. The challenge is that the same bound variable need never be repeated. = Sure for any given single sentence containing n different variables you can= define an equivalent single predicate with n arguments, but you can't do t= his for each of the infinitely many sentences in a language. > Other things you may want to look at: combinatory logic, > concatenative programming (or stack-based programming), point-free > style (or tacit programming), and the J programming language. Thanks for taking the trouble to make the suggestions, but I don't have the= requisite intellectual skills to scan outlines of those areas in the hope = of descrying a notation that doesn't require variable repetition. If you th= ink one of them provides a notation that doesn't require variable repetitio= n, it would be very precious to meif you were to explain it to me. --and. --=20 You received this message because you are subscribed to the Google Groups "= lojban" group. To post to this group, send email to lojban@googlegroups.com. To unsubscribe from this group, send email to lojban+unsubscribe@googlegrou= ps.com. For more options, visit this group at http://groups.google.com/group/lojban= ?hl=3Den.