All knots are trivial: a "proof" by sleight of hand

We take a close look at a classical magic trick performed with a string, where a trivial knot is seemingly isotoped into a trefoil, and generalize it to a family of magic tricks for transforming the unknot into other knots. We encode such a trick by depicting the target knot as a special type of knot diagram, which we call a “knotholder diagram”. By proving that all knots admit knotholder diagrams, we obtain variants of the trick for producing every knot.