Ore Mountain Mining Region recognised as a UNESCO world heritage site - for which it has been nominated - it should help to preserve it for future generations as a "developing cultural landscape". From the first discovery of silver ore in 1168 in Christiansdorf in the territory of the present-day borough of Freiberg, which is part of the Freiberg Mining Field, mining was carried out uninterruptedly in the Ore Mountains until 1990. Amongst the raw materials mined over the course of centuries were ores of the metals silver, tin, zinc, cobalt, nickel, copper and lead; but anthracite and uranium were also extracted into the
Ore extension polynomial derivative. Ore algebras are a class of iterated Ore extensions under suitable constraints that permit to develop a noncommutative extension of the theory of Gröbner bases. An element "f" of an Ore ring "R" is called 3.^ Azeddine, Ouarit. Extensions de ore d'anneaux noethériens à I. P. et identités auto-différentielles d'anneaux semi-premiers. Thèse de doctorat en Mathématiques (1991) Poitiers, France. http://www.theses.fr/1991POIT2260 Ore extension In mathematics, especially in the area of algebra known as ring theory, an Ore extension, named after Øystein Ore, is a special type of a ring extension whose properties are relatively well understood. Elements of a