Again, I don't know all the constraints, but clause boundaries are not
the only ones that block coreference. Consider:

a. Near him, Dan saw a snake. (him can equal Dan)
b. Near Dan, he saw a snake. (he does not equal Dan)

The initial element here is a preposed adverbial prepositional phrase --
there is no clause boundary between antecedent and pronoun.

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Johanna Rubba   Assistant Professor, Linguistics
English Department, California Polytechnic State University
One Grand Avenue  • San Luis Obispo, CA 93407
Tel. (805)-756-2184  •  Fax: (805)-756-6374 • Dept. Phone.  756-259
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                                       **
"Understanding is a lot like sex; it's got a practical purpose,
but that's not why people do it normally"  -            Frank  Oppenheimer
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