"Syntatic Theory" Query

[Rui Pedro Chaves]

Greetings,

can anyone please explain me how the 'Subject Extraction
Lexical Rule' as stated in Sag & Wasow (& Bender)
"Syntactic Theory" textbook is blocked from predicting b)
for a sentence such as 1):


1) John    smiled.

    subj-dtr   head-dtr
a) John       smiled.
    [1]NP     [SPR <[1]NP>
               COMPS <>
               GAP <> ]

    filler-dtr head-dtr
b) John       smiled.
    [1]NP      [SPR <>
                COMPS <>
                GAP <[1]NP> ]

----------------------
subj-extraction-lir effect:
  INPUT ( 'smiled'
          SPR <[1]>
          COMPS <>
          GAP <> )

  OUTPUT( 'smiled'
          SPR <>
          COMPS <>
          GAP <[1]>)
----------------------

Note that would not be possible in Pollard & Sag (1994:350).
Thank you very much in advance.
Cheers,
Rp