“…Also, the version of Cohn and Lempel is restricted to oriented Euler circuits and circuit partitions; the ψ transitions are not relevant to the permutations they considered. Many other authors have rediscovered, refined or restated the circuit-nullity formula in various ways [3,4,9,10,12,14,15,17,22,23,25,26,29,30,31,32,33,34,36].…”