Category
page 1Equivalence (mathematics)
isomorphism
In mathematics, an isomorphism is a structure-preserving mapping or morphism between two structures of the same type that can be reversed by an inverse mapping. Two mathematical structures are isomorphic if an isomorphism exists between them, and this is often denoted as . The word is derived .
equivalence relation
reflexive, symmetric and transitive relation
congruence
when two figures or objects in geometry have the same shape and size, or if one has the same shape and size as the mirror image of the other
similarity
idea in geometry

approximation
An approximation is anything that is intentionally similar but not exactly equal to something else.

equals sign
mathematical symbol used to indicate equality
equality
mathematical relationship asserting that two quantities have the same value
identity
equation that is satisfied for all values of the variables
isometry
thumb|upright=1.4|A Function composition|composition of two opposite isometries is a direct isometry. A reflection in a line is an opposite isometry, like (reflection w.r.t the center diagonal line) or (reflection w.r.t the right diagonal line) on the image. Translation is a direct isometry: a rigid motion.
matrix similarity
equivalence relation between matrices
logical equivalence
concept in logic
equivalence class
mathematical concept
congruence relation
equivalence relation in algebra
matrix congruence
equivalence relation between matrices
logical biconditional
term
elementary equivalence
Concept in model theory
normalization
statistical procedure
extensionality
In logic, extensionality, or extensional equality, refers to principles that judge objects to be equal if they have the same external properties. It stands in contrast to the concept of intensionality, which is concerned with whether the internal definitions of objects are the same.
==In mathematics==
The extensional definition of function equality, discussed above, is commonly used in mathematics.
A similar extensional definition is usually employed for relations: two relations are said to be equal if they have the same extensions.
equivalence of categories
abstract mathematics relationship
matrix equivalence
Mathematical equivalence relation
row equivalence
equivalence of matrices under row operations
equipollence
property of parallel segments that have the same length and the same direction
Morita equivalence
equivalence relation on rings
logic equality
logical operator in propositional calculus
quasi-isomorphism
In homological algebra, a branch of mathematics, a quasi-isomorphism or quism is a morphism A → B of chain complexes (respectively, cochain complexes) such that the induced morphisms
Congruence of squares
in number theory, a congruence commonly used in integer factorization algorithms
quasi-isometry
In mathematics, a quasi-isometry is a function between two metric spaces that respects large-scale geometry of these spaces and ignores their small-scale details. Two metric spaces are quasi-isometric if there exists a quasi-isometry between them. The property of being quasi-isometric behaves like an equivalence relation on the class of metric spaces.
characterization
term in mathematics
isomorphism of categories
relation of categories in category theory