[developers] LKB: Unification in lexicon

[Bart Cramer]

Dear delph-in members,

I have a question regarding the use of lexicons in the LKB system. I
would like to try the following line:

lex-verb-sein-1-fin-1-sg-pres-ind := tl-verb-sein-1 &
infl-verb-fin-1-sg-pres-ind & [ ORTH "bin" ].

As you can see, I handle the morphology in a somewhat sloppy way, by
just enumerating the forms (and I have my reasons to do so). However,
LKB does not seem to pick this up. When I use Debug -> Check lexicon,
I get an error message:

Unifications specified are invalid or do not unify.
Structure for LEX-VERB-SEIN-1-FIN-1-SG-PRES-IND coud not be created.

I am pretty sure that the unification is correct. When I put the
following in a regular type file:

wt-verb-sein-1-fin-1-sg-pres-ind := tl-verb-sein-1 &
infl-verb-fin-1-sg-pres-ind.

and the following in the lexicon:

lex-verb-sein-1-fin-1-sg-pres-ind := wt-verb-sein-1-fin-1-sg-pres-ind
& [ ORTH "bin" ].

where wt stands for "word type", it perfectly parses. The problem with
this solution, however, is that there is going to be a type for each
word, which leads to very, very long start-up times (lower bound
stuff...).

Can anyone enlighten me why this restriction in the lexicon is there,
and how I could circumvent it?

Many thanks in advance,

Bart.