INFORMATION
Two AmS-TeX source files follow: (1) a short one -- the front page of the 
preprint, (2) a longer one -- the body of the paper. They should be TeX-ed
and printed separately (because of different formats). They can be processed
neatly under:            AmS-TeX - Version 1.1d
                         ** As of 26 Aug 1988 **
Unfortunately there are long lines (longer than 80 characters) in the source 
file and I did not have the patience to cut them. If you have any difficulty
with the processing do not hesitate to ask a preprint
The paper has been accepted for publication in Journal of Statistical Physics.
ENDINFORMATION
BODY