Filler-gap mismatches

[Carl Pollard]

Hi Ron,

This is a long message (yours, I mean) and deserves a careful reply,
but for now just one brief remark on the following passage:

>
But what about the second instance, the situation where particular
predicates like "become" seem to impose categorial restrictions on
their complements that are more specific than the general phrase
structure rules provide for?  In the LFG literature there has been
some argument to the effect that many of what look like categorial
restrictions are actually restrictions of another sort, for example,
restrictions by semantic types (event, question, state...) that tend
to be realized by particular categories.  I think these arguments can
deal with a fair number of cases, but not necessarily all of them,
and the "become" vs "be" contrast seems to demonstrate the need for a
category-based account of at least some of the cases.

An obvious move would be to copy the category into the f-structure,
and then a simple f-structure constraint in "become" could be used to
restrict the type of complement.  This would both destroy the
representational modularity that we are striving for, and also cause
analyses of many different other phenomena to break down.  The
problem comes from the many-to-one nature of the structural
correspondence:  it would no longer be possible for two nodes of
different categories (say V and VP) to map to the same
f-structure--the standard way in which LFG represents head chains and
propagates feature dependencies.  This would put us on the slippery
slope:  we would have to figure out new ways of classifying features
so that some of them propagate and some of them don't, introduce
conventions that are not presently needed for passing features up
head-chains,... In the end we might arrive at a theory isomorphic to
HPSG.

Many people, particularly those on this list, might regard that as an
appropriate set of moves, but that's not the direction that we have
explored.  Instead, we have examined solutions that maintain the
modularity of representation but exploit the underlying architecture
to allow certain cross-module constraints to be stated.  Thus, we do
not encode in the f-structure any c-structure properties such as
category, dominance or linear order, even though there may be some
lexical predicates that impose special constraints on the phrasal
configurations that can realize their complements.
>>

LFG and HPSG agree in not allowing syntactic selection for dominance
or linear order. The only c-structure property HPSG allows selection for
is category. So one move LFG could make toward HPSG without giving
up its basic architecture is to move category out of c-structure and
into f-structure. You'd still have c-structure as a representation of
dominance and linear order. That would solve some problems, from
my point of view. Is there another reason to keep category labels
on c-structure nodes, aside from the fact that pEhrase markers in
ASPECTS OF SYNTAX looked that way?

Carl