syntax of comparatives and ellipsis in LFG

[Iddo Lev]

Hi,

I'm looking to read about the syntax of comparatives and other ellipsis
constructions in LFG. Can anyone recommend relevant references?

In particular, how is the OBJ in 2 related (in the f-structure) to the NP 1
in:
- John read 1:[a longer book than 2:[Bill wrote _OBJ_]].
and how is the PRED "did" related in the f-structure to the PRED "read" in:
- John read a longer book than Bill did.
and how are the clauses after "than" in these two sentences compare with the
simple NP 3 (i.e. how is the "deletion" treated in non-transformational
terms) in:
- John read a longer book than 3:[Bill].
- John is (4cm) tall(-er than Bill (is ((*20cm) wide))).

Also, I haven't seen f-structures of elliptical sentences like:
- John laughed and so did Bill / and Bill did so too.
nor have I read about the syntactic restrictions of the possible antecedents
of "so".

Thanks,
Iddo