Integraldomänen
Integraldomänen, also known as integral domains, are fundamental algebraic structures in abstract algebra. An integral domain is a commutative ring with a multiplicative identity that has no zero divisors. A commutative ring is a set with two operations, typically addition and multiplication, that satisfy certain properties like associativity, commutativity, distributivity, and the existence of an additive identity and additive inverses. The multiplicative identity, usually denoted by 1, is an element such that for any element a in the ring, a * 1 = 1 * a = a. The crucial property of an integral domain is the absence of zero divisors. This means that if a and b are elements in the ring and their product a * b = 0, then it must be the case that either a = 0 or b = 0 (or both). This property is analogous to the cancellation law in arithmetic: if ab = ac and a is not zero, then b must equal c. Examples of integral domains include the set of integers (Z) with the usual addition and multiplication, and the set of polynomials with integer coefficients. The field of fractions of an integral domain can be constructed, which is a field containing the integral domain. This concept is important in number theory and algebraic geometry.