Algebra and number theory •
Regular category, a kind of category that has similarities to both Abelian categories and to the category of sets •
Regular chains in computer algebra •
Regular element (disambiguation), certain kinds of elements of an algebraic structure •
Regular extension of fields •
Regular ideal (multiple definitions) •
Regular Lie group •
Regular matrix (disambiguation) •
Regular monomorphisms and
regular epimorphisms, monomorphisms (resp. epimorphisms) which equalize (resp. coequalize) some parallel pair of morphisms •
Regular numbers, numbers which evenly divide a power of 60 •
Regular p-group, a concept capturing some of the more important properties of abelian
p-groups, but general enough to include most "small"
p-groups •
Regular prime, a prime number
p > 2 that does not divide the class number of the
p-th cyclotomic field • The
regular representation of a group G, the linear representation afforded by the group action of G on itself •
Regular ring, a ring such that all its localizations have Krull dimension equal to the minimal number of generators of the maximal ideal •
von Neumann regular ring, or absolutely flat ring (unrelated to the previous sense) •
Regular semi-algebraic systems in computer algebra •
Regular semigroup, related to the previous sense •
*-regular semigroup Analysis •
Borel regular measure • Cauchy-regular function (or
Cauchy-continuous function,) a continuous function between metric spaces which preserves Cauchy sequences •
Regular functions, functions that are analytic and single-valued (unique) in a given region •
Regular measure, a measure for which every measurable set is "approximately open" and "approximately closed" • The
regular part, of a Laurent series, the series of terms with positive powers •
Regular singular points, in theory of ordinary differential equations where the growth of solutions is bounded by an algebraic function • Regularity, the
degree of differentiability of a function • Regularity conditions arise in the study of
first-class constraints in Hamiltonian mechanics •
Regularity of an elliptic operator •
Regularity theory of
elliptic partial differential equations
Combinatorics, discrete math, and mathematical computer science •
Regular algebra, or Kleene algebra •
Regular code, an algebraic code with a uniform distribution of distances between codewords •
Regular expression, a type of pattern describing a set of strings in computer science •
Regular graph, a graph such that all the degrees of the vertices are equal •
Szemerédi regularity lemma, some random behaviors in large graphs •
Regular language, a formal language recognizable by a finite state automaton (related to the regular expression) •
Regular map (graph theory), a symmetric tessellation of a closed surface •
Regular matroid, a matroid which can be represented over any field •
Regular paperfolding sequence, also known as the dragon curve sequence •
Regular tree grammar Geometry •
Castelnuovo–Mumford regularity of a coherent sheaf •
Closed regular sets in solid modeling •
Irregularity of a surface in algebraic geometry •
Regular curves •
Regular grid, a tesselation of Euclidean space by congruent bricks •
Regular map (algebraic geometry), a map between varieties given by polynomials • Regular point, a
non-singular point of an algebraic variety •
Regular point of a differentiable map, a point at which a map is a submersion •
Regular polygons, polygons with all sides and angles equal •
Regular polyhedron, a generalization of a regular polygon to higher dimensions •
Regular polytope, a generalization of a regular polygon to higher dimensions •
Regular skew polyhedron Logic, set theory, and foundations •
Axiom of Regularity, also called the Axiom of Foundation, an axiom of set theory asserting the non-existence of certain infinite chains of sets •
Partition regularity •
Regular cardinal, a cardinal number that is equal to its cofinality •
Regular modal logic Probability and statistics •
Regular conditional probability, a concept that has developed to overcome certain difficulties in formally defining conditional probabilities for continuous probability distributions • Regular
stochastic matrix, a stochastic matrix such that all the entries of some power of the matrix are positive
Topology •
Free regular set, a subset of a topological space that is acted upon disjointly under a given group action •
Regular homotopy •
Regular isotopy in knot theory, the equivalence relation of link diagrams that is generated by using the 2nd and 3rd Reidemeister moves only •
Regular space (or T_3) space, a topological space in which a point and a closed set can be separated by neighborhoods == Military ==