Comment on The Unknotting Number Is Not AdditiveparentComments−gus_massa11moThis example seems obvious to meThe counterexample has 7 crossings. Try to explain why the equivalent knot with only 5 crossing is not an counterexample and you may realize why it's not obvious.
Comments
The counterexample has 7 crossings. Try to explain why the equivalent knot with only 5 crossing is not an counterexample and you may realize why it's not obvious.