joi in tanru

[Logical Language Group <lojbab@ACCESS.DIGEX.NET>]

>From: Jorge Llambias <jorge@PHYAST.PITT.EDU>
>Subject:      Re: TECH: PROPOSED GRAMMAR CHANGE X5: Restriction of JOI
>
>lojbab:
>> Historically JOI entered the language as a tanru connective.
>> A black-and-red beach ball is neithr black nor red because it is
>> equally both.
>
>{ta xunre je xekri bolci} does not claim that the ball is black
>and that it is red, either, so it is a perfectly good translation.

Not knowing what Cowan has said in his papers, I am of the opinion that
it does indeed claim that the ball is both red and black, and that is
again the historical view.

>Tanru logical connectives are non-logical in the sense that they
>don't expand to two connected bridi like all the others.

They don't necessarily expand by rigid transformation, mainly because
they are tanru, but I believe they usually do so or come close as
actually used.  I know we've discussed some problem cases previously.

>(It is not clear to me that you can't say {ta xunre} when ta is only
>partly but significantly red, but that is another issue, concerning
>how one understands the meaning of {xunre}.)

You could say it, but another person might misunderstand.  Especially if
you have one all red and one mixed black and red, "le xunre" would
almost certainly NOT include the mixed one.

>> Thus JCB used "ze" which we made "joi".
>
>But JCB's language is not Lojban.

Ah, but the converse ...

Seriously, we have tried NOt to change anything JCB did without good
reason.

>Were JCB's tanru logical connectives shortened forms of full bridi?

It was never decided (or was decided self-contradictorily), just as it
has never really been decided for Lojban.  Our good buddy pc identified
the same problems when he worked with JCB as he did for us, so
effectively the answer is the same for both.

The fact that we HAVE joi and je available for tanru allows one to make
distinctions of just the sort we have been discussing.  The exact
logical claim of any tanru is open to question but relative claims of
two related tanru used by the same speaker in similar contexts ARE
comparable.

As a result of this fact it seems clear that there ARE useful
distinctions to be made using both cmavo in tanru, andpeople should
choose the one that makes their intended meaning clearest, without
worrying about possible logical expansion.

lojbab