Subject: [lojban] Re: nai in UI (was: BPFK phpbb)

From: Pierre Abbat <[email-masked]>
Date: Wed, 30 Apr 2003 18:31:56 -0400

On Wednesday 30 April 2003 12:52, Jim Carter wrote:
> Hey, wait a minute! Think modularity. There are morpheme streams that can
> or can't be split into valid Lojban words. There are word streams that can
> or can't be parsed into valid syntax trees. And there are semantic
> constructs that are or aren't Carroll-esque. The phrase "meaningful
> concept" is too vague to be a meaningful concept. I would like to amend
> your pronouncement to say, a valid parser passes all valid word streams
> (putting out a correct syntax tree) and rejects all invalid word streams,
> where validity is judged from the grammar. In other words, the parser does
> or doesn't truly realize that grammar. (I.e. makes it real.) (And as a
> separate module, the semantic analyser may have an opinion about
> jabberwockishness.)
>
> I'm sure we can come up with natlang examples where the parsing depends in
> an essential way on the meaning of the words (not just their syntactic
> category), but I can't think of one so early in the morning. But that kind
> of a pain in the butt doesn't belong in Lojban. Think modularity!

I agree (and for similar reasons separated lexing words from checking their 
validity). We have a context-free grammar that parses {kau} as UI, which can 
go anywhere. We can have another layer that checks whether {kau} follows a 
question word, whether it's in an abstraction, and whether it's on the 
indifferent side of {ju/u/gi'u}, and decides whether it makes sense there. It 
can also check whether a brivla has a sumti in a nonexistent place, whether a 
number string is valid, whether {ko'a} or a lervla has an antecedent, etc.

phma