Received: from localhost ([::1]:49718 helo=stodi.digitalkingdom.org) by stodi.digitalkingdom.org with esmtp (Exim 4.76) (envelope-from ) id 1TyzBt-0004Qn-Lu; Fri, 25 Jan 2013 22:24:37 -0800 Received: from mail-we0-f181.google.com ([74.125.82.181]:35481) by stodi.digitalkingdom.org with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) (envelope-from ) id 1TyzBj-0004Qh-8i for jbovlaste@lojban.org; Fri, 25 Jan 2013 22:24:35 -0800 Received: by mail-we0-f181.google.com with SMTP id t44so524504wey.26 for ; Fri, 25 Jan 2013 22:24:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:content-type; bh=bfhXTBAV7oJveGumcsIo2cbjS75t2IaPoIqRLHFtuek=; b=XFg6Ws2i8Q1aC2kNo7OKV8c5bTla79Q7zi2HVkSPCSd5sZFDjaYlNrtVozr2n6w34s djmzePKRvvzNbHI1hF25gc8mXv6EBhpXEi/9kniBau13aZV2Igv/+kLEaNXel6jpuhxM ulVXlGzECytjVErsttqZuwZ2KgtWWwZEeSCpRSJezPi3gTdATKxxXgafMLL8+dWEkh6m d1DtWRQZ7OJmqa+YTAp2wTlANqFYd4omG2D4Q5T8iWN8CMStwRTzr+DhAw7TsKprVQPN KYHD135eFEUY9+1sFAQDt4hKVzL7iI9zwRYF08eGFVhZ/rzBbq0SGleaqd4nzI6E0Kxy Kikg== MIME-Version: 1.0 X-Received: by 10.194.5.74 with SMTP id q10mr12432320wjq.13.1359181459710; Fri, 25 Jan 2013 22:24:19 -0800 (PST) Received: by 10.194.37.132 with HTTP; Fri, 25 Jan 2013 22:24:19 -0800 (PST) In-Reply-To: References: <20130124175134.GA14317@mercury.ccil.org> <51017FF7.504@plasmatix.com> <20130124221349.GB20636@mercury.ccil.org> <20130125151703.GB20813@mercury.ccil.org> Date: Sat, 26 Jan 2013 10:24:19 +0400 Message-ID: From: Gleki Arxokuna To: jbovlaste@lojban.org X-Spam-Score: -0.1 (/) X-Spam_score: -0.1 X-Spam_score_int: 0 X-Spam_bar: / Subject: Re: [jbovlaste] berbere, berberi X-BeenThere: jbovlaste@lojban.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: jbovlaste@lojban.org List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============2354738242083534405==" Errors-To: jbovlaste-bounces@lojban.org --===============2354738242083534405== Content-Type: multipart/alternative; boundary=047d7b45070e1762a804d42b1828 --047d7b45070e1762a804d42b1828 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Let's imagine that we have a brivla. Let it be {selseli}. Now imagine that you see a rafsi {selsely-}. Is it a rafsi of {selseli}? Or may be there is another brivla, {selsela}? Or may be there is no {selsela} but it'll be added later, may be in 50 years making old texts with {selsely-} ambiguous. If we allow brivla that differ in the last vowel only then we should delete that proposal of fu'ivla rafsi from CLL. This is not human-friendly. On Sat, Jan 26, 2013 at 3:24 AM, Jorge Llamb=C3=ADas = wrote: > On Fri, Jan 25, 2013 at 1:17 PM, John Cowan > wrote: > > Jorge Llamb=C3=ADas scripsit: > > > >> Surely that can't have been the reason. How did you prove that > >> decompositions with CCVCy- rafsi were unambiguous, and why wouldn't > >> the same method of proof work for CCVVCy-? The proof seems just as eas= y. > > > > Our proof engine was Nora, who reduced the existing morphology to a > > set of cases. Looking at them, we were reasonably sure the CCVVCy > > set didn't break the proof, but Nora didn't have time to check it. > > Those cases weren't published anywhere I know of, and are either lost > > or buried in Bob's paper archive, which amounts to the same thing. > > If you want to produce and publish such a proof, I'm sure Lojbanists > > everywhere would be happy to have it. > > It seems trivial: > > If CCVVCy- is at the beginning of the string, no initial cmavo form > can drop as a cmavo, so there's no chance of tosmabru type issues. > > There's also no chance of slinku'i type issues because CVVCy, VVCy, > VCy, Cy are not valid rafsi. > > If it's not at the beginning of the string, no initial segment of > CCVVCy- could be part of another rafsi for the same reason that no > slinku'i is possible > > That's the proof. What am I missing? > > >> > Note that a PEG grammar, unlike a YACC grammar, does not prove this, > >> > because PEG grammars silently override ambiguities using the rule > >> > "first =3D best". That isn't good enough for Lojban morphology, > >> > so I consider the CLL proposal a dead letter. > >> > >> The YACC grammar doesn't handle morphology at all, so I fail to see > >> how this has anything to do with the issue. > > > > I was speaking generally. YACC grammars can provide a proof of > > unambiguity in certain circumstances. PEG grammars cannot: they are > > not in that business. > > PEGs are unambiguous by construction, they don't need to be proved > unambiguous, since they can't fail to be unambiguous. > > Whatever issues you may have with the PEG grammar for Lojban (and I > can think of some) they cannot be about potential ambiguities, it > can't have any. > > >> If the PEG morphology isn't good enough for Lojban, then Lojban doesn'= t > >> have a formal morphology at all, because the PEG is the only one we > >> have so far. > > > > The fact that the morphology hasn't changed means that the old proof > > is still valid, even though we no longer have access to it. That's an > > unfortunate state of affairs, but it's where we are. > > Not really. It's obvious to me that Lojban's morphology is > unambiguous, but that doesn't mean that any old (purported) proof of > its unambiguity is valid. I happily accept Nora's proof was probably > valid though. It's also equally obvious that CCVVCy- rafsi or the > extended 'y- rafsi don't cause ambiguity. > > BTW, the PEG grammar doesn't single out CCVVCy- rafsi. It accepts all > final-vowel-dropping fu'ivla rafsi that don't cause ambiguities. > CCVVCy- is just one particular instance of those. > > mu'o mi'e xorxes > > _______________________________________________ > jbovlaste mailing list > jbovlaste@lojban.org > http://mail.lojban.org/mailman/listinfo/jbovlaste > --047d7b45070e1762a804d42b1828 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Let's imagine that we have a brivla. Let it be {selsel= i}.

Now imagine that you see a rafsi {selsely-}. I= s it a rafsi of {selseli}? Or may be there is another brivla, {selsela}? Or= may be there is no {selsela} but it'll be added later, may be in 50 ye= ars making old texts with {selsely-} ambiguous.

If we allow brivla that differ in the last = vowel only then we should delete that proposal of fu'ivla rafsi from CL= L. This is not human-friendly.



On Sat, Jan 26, 2013 at 3:24 AM, Jorge L= lamb=C3=ADas <jjllambias@gmail.com> wrote:
On Fri, Jan 25, 2013 at 1:17 PM, John Cowan <cowan@mercury.ccil.org> wrote: > Jorge Llamb=C3=ADas scripsit:
>
>> Surely that can't have been the reason. How did you prove that=
>> decompositions with CCVCy- rafsi were unambiguous, and why wouldn&= #39;t
>> the same method of proof work for CCVVCy-? The proof seems just as= easy.
>
> Our proof engine was Nora, who reduced the existing morphology to a > set of cases. =C2=A0Looking at them, we were reasonably sure the CCVVC= y
> set didn't break the proof, but Nora didn't have time to check= it.
> Those cases weren't published anywhere I know of, and are either l= ost
> or buried in Bob's paper archive, which amounts to the same thing.=
> If you want to produce and publish such a proof, I'm sure Lojbanis= ts
> everywhere would be happy to have it.

It seems trivial:

If CCVVCy- is at the beginning of the string, no initial cmavo form
can drop as a cmavo, so there's no chance of tosmabru type issues.

There's also no chance of slinku'i type issues because CVVCy, VVCy,=
VCy, Cy are not valid rafsi.

If it's not at the beginning of the string, no initial segment of
CCVVCy- could be part of another rafsi for the same reason that no
slinku'i is possible

That's the proof. What am I missing?

>> > Note that a PEG grammar, unlike a YACC grammar, does not prov= e this,
>> > because PEG grammars silently override ambiguities using the = rule
>> > "first =3D best". =C2=A0That isn't good enough = for Lojban morphology,
>> > so I consider the CLL proposal a dead letter.
>>
>> The YACC grammar doesn't handle morphology at all, so I fail t= o see
>> how this has anything to do with the issue.
>
> I was speaking generally. =C2=A0YACC grammars can provide a proof of > unambiguity in certain circumstances. =C2=A0PEG grammars cannot: they = are
> not in that business.

PEGs are unambiguous by construction, they don't need to be prove= d
unambiguous, since they can't fail to be unambiguous.

Whatever issues you may have with the PEG grammar for Lojban (and I
can think of some) they cannot be about potential ambiguities, it
can't have any.

>> If the PEG morphology isn't good enough for Lojban, then Lojba= n doesn't
>> have a formal morphology at all, because the PEG is the only one w= e
>> have so far.
>
> The fact that the morphology hasn't changed means that the old pro= of
> is still valid, even though we no longer have access to it. =C2=A0That= 's an
> unfortunate state of affairs, but it's where we are.

Not really. It's obvious to me that Lojban's morphology is unambiguous, but that doesn't mean that any old (purported) proof of its unambiguity is valid. I happily accept Nora's proof was probably valid though. It's also equally obvious that CCVVCy- rafsi or the
extended 'y- rafsi don't cause ambiguity.

BTW, the PEG grammar doesn't single out CCVVCy- rafsi. It accepts all final-vowel-dropping fu'ivla rafsi that don't cause ambiguities. CCVVCy- is just one particular instance of those.

mu'o mi'e xorxes

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