mutated graphs 1000: not self-dual 971; writhe != 0 in 0 (all of them among the non-self-dual ones: True)
control 2: B u psi(C*), C != B same pair and edge count: 712 knots, self-dual 300, writhe != 0 in 0
control 3: random nonseparable plane graphs with odd tau: 98 knots, self-dual 14, writhe != 0 in 79
