2 problems

Sharp region unknotting conjecture. The sharp upper bound provided in the paper is equal to the region unknotting number for both $K(p,np)$ and $K(p,np+1)$.

The figure-eight knot is a knot, and an H(2)-move is the operation of adding a twisted band while preserving the number of components. The H(2)-unknotting number $u_{2}(K)$ of a kn…