Raising

[Julia Barron]

Hello. I wonder if anyone can give me some references for a 
treatment of "raising" in LFG. I am familiar with the
f-structure representations of "raised" subjects and objects, but
I am not sure how to handle "raising"  of neg and modals in
expressions such as:
"I can't seem to find any references to this"
"I don't seem to be able to find any references"
contrasting with 
"I seem not to be able to find..." and "I seem unable to find"

Whilst I can imagine a motivation for "raised" subjects in English,
I'm not so clear about the motivation for "raising" negs and
modals. Does anyone have any ideas/opinions about this?

Thanks 
Julia Barron

jbarron at borage.win-uk.net