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Parity structures and generating functions from Boolean rings
David Petrie Moulton^{1}
Department of Mathematics
University of Wisconsin
Madison, WI 53706

William A. Stein
Department of Mathematics
University of California
Berkeley, CA 94720
October 27, 1999
Abstract:
Let S be a finite set and T be a subset of the power set of S.
Call T a parity structure for S if, for
each subset b of S of odd size, the number of subsets of b
that lie in T is even. We classify parity structures using generating
functions from a free boolean ring.
We also show that if T is a parity structure, then, for each
subset b of S of even size, the number of subsets of b of
odd size that lie in T is even. We then give several other
properties of parity structures and discuss a generalization.
William Arthur Stein
19991027