* Thursday, 2011-11-24 at 21:18 -0300 - Jorge Llambías <jjllambias@gmail.com>:
> On Thu, Nov 24, 2011 at 1:41 AM, Martin Bays <mbays@sdf.org> wrote:
> >
> > Probably not bugs:
> > This might at first seem wrong:
> > > na ku mi noi brode cu broda
> > Prop:!(brode(mi) /\ broda(mi))
>
> It does seem wrong to me. A noi-clause is more like a presupposition,
> not directly part of the claim.
>
> I'd say it's more like:
>
> presupp Prop: brode(mi)
> main Prop: !broda(mi)
Yes, quite possibly.
I was working under the assumption that {noi} should be part of this
basic logical fragment of lojban, meaning in particular that we don't
have to break out of existing quantifiers when parsing it.
Clearly some parts of lojban do require breaking out in this way -
question words, anaphora and probably xorlo being examples - so adding
{noi} to that list wouldn't be too shocking. All else being equal,
however, I would prefer not to.
> > but consider that e.g.
> > > na ku da ro broda be da ku noi brodi cu brodu
> > Prop:!EX x1. FA x2:(broda(_,x1)). (brodu(x1,x2) /\ brodi(x2))
> > is probably right.
>
> I don't think a noi-clause is well-defined when it is attached to
> something that doesn't have referents. You need a referent in order to
> be able to make a comment about it. It may be that noi forces
> something like:
>
> ?presupp Prop: FA x1. FA x2:(broda(_,x1). brodi(x2)
> main Prop: !EX x1. FA x2:(broda(_,x1)). brodu(x1,x2)
>
> I'm not completely sure if that's exactly what the presupposition
> should be, but I do believe the main proposition should not be
> affected if you remove any noi-clause from it.
I don't know.
Consider analogous english phrases:
Not one of the farmers owns donkeys, which he beats, with long ears.
(excuse sexist pronoun; using anything else would confuse the issue)
I think the relative phrase here is, on its own, unambiguously
incidental. But the sentence does not imply that all of the farmers beat
their donkeys. The overall effect is that the incidental phrase does act
restrictively, just as in my interpretation of the corresponding lojban:
no le cange cu ponse su'o xasli noi ri darxi zi'e poi clani se kerlo
Prop: {le} x1:(cange(_)). EQ(0) x2:(me(_,x1)). EX x3:((xasli(_) /\
<clani(_)><kerlo>( ,_))). (ponse(x2,x3) /\ darxi(x2,x3))
jbo: le cange ku goi ko'a 0 da poi ke'a me ko'a ku'o su'o de poi ge ke'a
xasli gi zo'e ke clani kerlo ke'e ke'a ku'o zo'u ge da ponse de gi
da darxi de
Similarly: "Each boy carried his bag. Two of the boys carried his bag,
which contained his lunch, on his head" doesn't imply that each bag
contained its owner's lunch. Again, this agrees with:
ro lo nanla goi ny cu bevri lo ri dakli .i je re ny stedu cpana bevri lo
ri dakli noi vasru lo ri sanmi
Prop: {lo} x1:(nanla(_)). FA x2:(me(_,x1)). {lo} x3:((srana(x2,_) /\
dakli(_))). EQ(2) x4:(me(_,x1)). {lo} x5:((srana(x4,_) /\
dakli(_))). (bevri(x2,x3) /\ (<<stedu(_)><cpana>(_)><bevri>(x4,x5)
/\ {lo} x6:((srana(x4,_) /\ sanmi(_))). vasru(x5,x6)))
jbo: lo nanla ku goi ko'a ro da poi ke'a me ko'a ku'o lo poi'i ge da
srana ke'a gi ke'a dakli kei ku goi ko'e 2 de poi ke'a me ko'a ku'o lo
poi'i ge de srana ke'a gi ke'a dakli kei ku goi ko'i zo'u ge da bevri
ko'e gi ge de ke ke stedu cpana ke'e bevri ke'e ko'i gi lo poi'i ge de
srana ke'a gi ke'a sanmi kei ku goi ko'o zo'u ko'i vasru ko'o
Then again, the english "It is impossible that I, who am great, could
fail" probably isn't falsified by my possibly not being great (although
I suspect it's ambiguous). So incidentals in english probably are
sometimes scope-jumping in the way you suggest.
> > Also,
> > > ro da na ku broda .i je de brode
> > Prop:FA x1. !EX x2. (broda(x1) /\ brode(x2))
> > is right, because
> > > ro da na ku broda de .i je de brode
> > Prop:FA x1. !EX x2. (broda(x1,x2) /\ brode(x2))
> > has to be; c.f.
> > > ro da na broda de .i je de brode
> > Prop:FA x1. EX x2. (!broda(x1,x2) /\ brode(x2)) .
>
> This is a hairy issue. My instinct has always been that ".ije" should
> be able to connect prenexed sentences, but the official grammar does
> say otherwise.
It does. I initially implemented only 'subsentence'; getting from that
to 'text' was much more difficult than I had anticipated, largely
because of this kind of issue.
But having connected sentences share a common prenex does seem often
useful, e.g. to keep a bound variable alive, and unintuitive only if you
have the wrong intuition (which I certainly did at first!).
> BTW, how do you analyse "su'o da na broda" and "su'o da na broda gi'e na brode"?
Prop: EX x1. !broda(x1)
and
Prop: EX x1. (!broda(x1) /\ !brode(x1))
respectively.
This current handling does mean we get possibly unintuitive results once
tailterms are brought in:
da na broda de
Prop: EX x1. EX x2. !broda(x1,x2)
jbo: su'o da su'o de zo'u na ku da broda de
su'o da na broda gi'e na brode vau de
Prop: EX x1. EX x2. (!broda(x1,x2) /\ !brode(x1,x2))
jbo: su'o da su'o de zo'u ge na ku da broda de gi na ku da brode de
The obvious alternative would be to have {na broda} work like {broda be
na ku}, which I think corresponds to what you suggest on the BPFK
section page, giving us
da broda be na ku de
Prop: EX x1. !EX x2. broda(x1,x2)
jbo: su'o da zo'u na ku su'o de zo'u da broda de
but
su'o da broda na ku gi'e brode na ku
Prop: EX x1. !!(broda(x1) /\ brode(x1))
jbo: su'o da zo'u na ku na ku ge da broda gi da brode
and
su'o da broda be na ku gi'e brode be na ku
Prop: EX x1. !!(broda(x1) /\ brode(x1))
jbo: su'o da zo'u na ku na ku ge da broda gi da brode
and
su'o da broda be na ku gi'e brode be na ku vau de
Prop: EX x1. !EX x2. !(broda(x1,x2) /\ brode(x1,x2))
jbo: su'o da zo'u na ku su'o de zo'u na ku ge da broda de gi da brode de
Contrast all that with
su'o da broda na gi'e nai brode vau de
Prop: EX x1. EX x2. (!broda(x1,x2) /\ !brode(x1,x2))
jbo: su'o da su'o de zo'u ge na ku da broda de gi na ku da brode de
I'm not sure what the correct behaviour is here (also generally with
tailterms of connected briditails, even without the negation)
By the way: in case you or anyone else wants to play with my current
implementation without compiling it yourself, you can now do so by
sshing to:
gonzales.homelinux.org (username tersmu; password tersmu)
I won't actually be watching you to the extent that the (traditional)
motd might suggest.
Martin
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