countably infinite space
101Orthonormal basis — In mathematics, particularly linear algebra, an orthonormal basis for inner product space V with finite dimension is a basis for V whose vectors are orthonormal.[1][2][3] For example, the standard basis for a Euclidean space Rn is an orthonormal… …
102Outer measure — In mathematics, in particular in measure theory, an outer measure or exterior measure is a function defined on all subsets of a given set with values in the extended real numbers satisfying some additional technical conditions. A general theory… …
103Quantum logic — In mathematical physics and quantum mechanics, quantum logic is a set of rules for reasoning about propositions which takes the principles of quantum theory into account. This research area and its name originated in the 1936 paper by Garrett… …
104Lebesgue measure — In mathematics, the Lebesgue measure, named after Henri Lebesgue, is the standard way of assigning a length, area or volume to subsets of Euclidean space. It is used throughout real analysis, in particular to define Lebesgue integration. Sets… …
105Pontryagin duality — In mathematics, in particular in harmonic analysis and the theory of topological groups, Pontryagin duality explains the general properties of the Fourier transform. It places in a unified context a number of observations about functions on the… …
106Minkowski-Bouligand dimension — In fractal geometry, the Minkowski Bouligand dimension, also known as Minkowski dimension or box counting dimension, is a way of determining the fractal dimension of a set S in a Euclidean space R^n, or more generally in a metric space ( X , d ) …
107Differentiable manifold — A nondifferentiable atlas of charts for the globe. The results of calculus may not be compatible between charts if the atlas is not differentiable. In the middle chart the Tropic of Cancer is a smooth curve, whereas in the first it has a sharp… …
108Minkowski–Bouligand dimension — Estimating the box counting dimension of the coast of Great Britain In fractal geometry, the Minkowski–Bouligand dimension, also known as Minkowski dimension or box counting dimension, is a way of determining the fractal dimension of a set S in a …
109Linear algebra — R3 is a vector (linear) space, and lines and planes passing through the origin are vector subspaces in R3. Subspaces are a common object of study in linear algebra. Linear algebra is a branch of mathematics that studies vector spaces, also called …
110System of imprimitivity — The concept of system of imprimitivity is used in mathematics, particularly in algebra and analysis, both within the context of the theory of group representations. It was used by George Mackey as the basis for his theory of induced unitary… …
