Ribbon Knot

If the knot  is the boundary  of a singular disk  which has the property that each self-intersecting component is an arc  for which  consists of two arcs in , one of which is interior, then  is said to be a ribbon knot.

Every ribbon knot is a slice knot, and it is conjectured that every slice knot is a ribbon knot.

Knot , illustrated above, is a ribbon knot (Rolfsen 1976, p. 225).

REFERENCES:

Rolfsen, D. Knots and Links. Wilmington, DE: Publish or Perish Press, p. 225, 1976.