Date: Fri, 16 Dec 1994 05:12:15 -0500
From: Logical Language Group <lojbab>
Message-Id: <199412161012.AA25412@access3.digex.net>
To: topic@math.hr
Subject: Re: some help needed
Cc: lojbab@access.digex.net, lojban@cuvmb.cc.columbia.edu
Status: RO

>What is the difference (except in brevity, of course; I'm not talking about
>that now) between
>
>da,   as defined by {da poi du'u broda}, and
>
>ko'a, as defined by {lo goi ko'a du'u broda}
>
>co'o mi'e. goran.

Well, your second sentence is ungrammatical.

ko'a is a specific pronoun with a definite referent.  In theory it should
always be used only after defining it, at which point you could replace
"ko'a" by the string it is equivalenced to, and get a correct understanding.

The two ways to assign ko'a are to make a predication in which all other
relevant sumti are specified, and ko'a fills one place.  This is usually
done with the poredicate "du".  But in a sentence like "ko'a klama le zarci"
a later reference to ko'a would be quivalent to "le klama be le zarci".
(This usage is not significantly covered in any text description unless
Cowan does so in one of his papers, but the draft textbook did use  "ko'a du 
..." without explaining it.

The other way is to express a sumti and specifically assign it to ko'a for
later reference, using goi.  goi is symmetrical, so the following are
equivalent:
la djan goi ko'a cu klama le zarci
ko'a goi la djan cu klama le zarci

Thereafter ko'a means "la djan".  


But goi requires a valid sumti-form on each side, so your example with only
"lo" on the left is ungrammatical.  If you mean "ko'a goi lo du'u broda"
then I think the answer depends on the current discussion.  If "lo is short
for a implicit "DA poi" construct, then you are asking whether there is
a difference between
da poi du'u broda    and
ko'a goi da poi du'u broda

which is clearly the same (unless I screwed up with terminators somehow, which
I doubt).

lojbab