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.
The Scottish Borders, which is also referred to simply as the Borders, stretches from the Pentland, Moorfoot and Lammermuir Hills that mark the boundary with the Lothians in the north, to the Cheviot Hills which, along with the River Tweed, mark the border with England in the south.