Schubert (1949) showed that every knot can be uniquely decomposed (up to the order in which the decomposition is performed) as a knot sum of a class of knots known as prime knots, which cannot themselves be further decomposed (Livingston 1993, p. 5; Adams 1994, pp.
The Moors were Muslim inhabitants of the Maghreb, the Iberian Peninsula, Sicily, and Malta during the Middle Ages.
Moor, in English usage, a Moroccan or, formerly, a member of the Muslim population of what is now Spain and Portugal. Of mixed Arab, Spanish, and Amazigh (Berber) origins, the Moors created the Arab Andalusian civilization and subsequently settled as refugees in North Africa between the 11th and 17th centuries.