  In this paper, we give a new bijective proof of a multiset analogue of
even-odd permutations identity. This multiset version is equivalent to the
original coin arrangements lemma which is a key combinatorial lemma in the
Sherman's Proof of a conjecture of Feynman about an identity on paths in planar
graphs related to combinatorial solution of two dimensional Ising model in
statistical physics.

Combinatorics;Computation and Language