The basic problem of knot theory, the recognition problem, is determining the equivalence of two knots. Algorithms exist to solve this problem, with the first given by Wolfgang Haken in the late 1960s . Nonetheless, these algorithms can be extremely time-consuming, and a major issue in the theory is to understand how hard this problem really is . The special case of recognizing the unknot, called the unknotting problem, is of particular interest . In February 2021 Marc Lackenby announced a new unknot recognition algorithm that runs in quasi-polynomial time.