** For every non-empty set S there is a binary operation defined on S that makes it a group.

** The Nielsen – Schreier theorem, that every subgroup of a free group is free.

** In topology, morphisms between topological spaces are called continuous maps, and an automorphism of a topological space is a homeomorphism of the space to itself, or self-homeomorphism ( see homeomorphism group ).

** Terminology of the British Isles, discusses the sometimes ambiguous or contentious names for parts of the island group

** The B-52's ( album ), an album by the eponymous group

** School band, a group of student musicians who rehearse and perform instrumental music together

** Marching band, a group of performers that consist of instrumental musicians who generally perform outdoors and incorporate some type of marching ( and possibly other movements ) with their musical performance

** Han Chinese, the dominant ethnic group in mainland China, Taiwan and Singapore

** the exceptional and twisted groups of Lie type ( including the Tits group ).

** Religion and blood group with RH factor

** Religion ( or " NRE " if none ) and blood group with RH factor

** Blood group with RH factor

** First and middle initials and suffix ; blood group

** Social Security number with no dashes or spaces followed immediately by " USN ", space, blood group

** Blood group

** Fermentative hydrogen production, the fermentative conversion of organic substrate to biohydrogen manifested by a diverse group of bacteria

** The Pferdestärke PS ( German translation of horsepower ) is a name for a group of similar power measurements used in Germany around the end of the 19th century, all of about one metric horsepower in size.

** Propithecus diadema group

** Propithecus verreauxi group

** Parabolic induction: a method of constructing group representations of a reductive group from representations of its parabolic subgroups.

** five lectures, heard by the group, as blip. tv videos

** Diagnosis-related group

** Kuru ( archaeology ), an Indo-Aryan ethnic group

** Order † Sparassodonta ( formerly viewed as marsupials, now as a sister group of metatherians )

** In order theory, see order automorphism.

** Microevolution: species — speciation — adaptation — selection — natural selection — directional selection — sexual selection — genetic drift — sexual reproduction — asexual reproduction — colony — allele frequency — neutral theory of molecular evolution — population genetics — Hardy-Weinberg principle

** Quantum chromodynamics, a theory of the strong interaction ( color force )

** Dual ( category theory ), a formalization of mathematical duality

** LTI system theory

** electron theory of metals

** Backward induction in game theory and economics

** for his profound contributions to three major areas of operations research and management science: inventory theory, dynamic programming and lattice programming.

** in recognition of his fundamental contributions to game theory and related areas

** for his contributions to queueing theory, applied probability and stochastic modelling

** Limit ( category theory )

** Most forms of cognitivism hold that some such propositions are true, as opposed to error theory, which asserts that all are erroneous.

** Error theory, another form of moral anti-realism, holds that although ethical claims do express propositions, all such propositions are false.

** In topos theory, the ( codomain of the ) subobject classifier of an elementary topos.

** In number theory, Ω ( n ) is the number of prime divisors of n.

** In relational database theory to represent NULL, a missing or inapplicable value.

** In set theory, the first uncountable ordinal number ( more commonly written as ω < sub > 1 </ sub >)

** In number theory, ω ( n ) is the number of distinct prime divisors of n.

** In number theory, an arithmetic function

** the ultraproduct, in model theory.

** General relativity, Albert Einstein's theory of gravitation

** Special relativity, a theory formulated by Albert Einstein, Henri Poincaré, and Hendrik Lorentz

** Constructionism ( learning theory )

** Coherence theory of truth