Proizvolov's identity concerns a set partition of the integers 1, 2, ..., into two
-element sets. Write one set
in increasing order
and the other in decreasing order
. The identity
states that
For each ,
at least one of
and
exceeds
.
Otherwise the first
terms of the increasing list and the last
terms of the decreasing list would give
distinct integers no greater
than
.
The pairwise maxima are therefore exactly
,
, ...,
, while the pairwise minima are
1, 2, ...,
.
It follows that