Every one of these objects can be uniquely decomposed into primes by Schubert’s theorem. Gordon and Leucke proved a theorem about determining one of these objects from their complement, which is compact (15[1])when working in a 3-sphere. Tame examples of these objects (15[1])can be (15[1])“framed” by a solid torus. Reidemeister moves (15[2])leave invariant (15[2])a quantity describing these objects (15[1])that is built recursively from skein relations and named after six mathematicians. The HOMFLY, (*) Alexander, and Jones polynomials describe these objects. (10[1])Links are unions of these objects, which are composed of tangles. Prefixing the name of these objects with “un-” gives their simplest case, which has fewer crossings than the trefoil and figure-eight examples. For 10 points, name these embeddings in space of a tied string. ■END■