 Therefore the Hamiltonian cycle problem is computable on such graphs in polynomial time.In characteristic 2, the Hamiltonian cycle polynomial of an "n"×"n"-matrix is zero if "n" > 2k where k is its rank or if it's involutory and "n" > 1.Besides, in an arbitrary ring formula_17 for any skew-symmetric "n"×"n"-matrix formula_5 there exists a power series in a formal variable formula_19