closed function
121Janus — For other uses, see Janus (disambiguation). Bifrons redirects here. For other uses, see Bifrons (disambiguation). A statue representing Janus Bifrons in the Vatican Museums In ancient Roman religion and mythology, Janus is the god of beginnings… …
122Separated sets — In topology and related branches of mathematics, separated sets are pairs of subsets of a given topological space that are related to each other in a certain way.The notion of when two sets are separated or not is important both to the notion of… …
123Extreme value theorem — This article is about continuous functions in analysis. For statistical theorems about the largest observation in a sequence of random variables, see extreme value theory. A continuous function ƒ(x) on the closed interval [a,b] showing the… …
124Sierpiński space — In mathematics, Sierpiński space (or the connected two point set) is a finite topological space with two points, only one of which is closed.It is the smallest example of a topological space which is neither trivial nor discrete. It is named… …
125Manifold — For other uses, see Manifold (disambiguation). The sphere (surface of a ball) is a two dimensional manifold since it can be represented by a collection of two dimensional maps. In mathematics (specifically in differential geometry and topology),… …
126List of first-order theories — In mathematical logic, a first order theory is given by a set of axioms in somelanguage. This entry lists some of the more common examples used in model theory and some of their properties. PreliminariesFor every natural mathematical structure… …
127List of algebraic structures — In universal algebra, a branch of pure mathematics, an algebraic structure is a variety or quasivariety. Abstract algebra is primarily the study of algebraic structures and their properties. Some axiomatic formal systems that are neither… …
128Germany — /jerr meuh nee/, n. a republic in central Europe: after World War II divided into four zones, British, French, U.S., and Soviet, and in 1949 into East Germany and West Germany; East and West Germany were reunited in 1990. 84,068,216; 137,852 sq.… …
