Band sum

In geometric topology, a band sum of two "n"-dimensional knots "K"1 and "K"2 along an ("n" + 1)-dimensional 1-handle "h" called a "band" is an "n"-dimensional knot "K" such that:
"K" is the "n"-dimensional knot obtained by this surgery.
A band sum is thus a generalization of the usual connected sum of knots.