free subgroup
81Euclidean plane isometry — In geometry, a Euclidean plane isometry is an isometry of the Euclidean plane, or more informally, a way of transforming the plane that preserves geometrical properties such as length. There are four types: translations, rotations, reflections,… …
82HNN extension — In mathematics, the HNN extension is a basic construction of combinatorial group theory.Introduced in a 1949 paper Embedding Theorems for Groups [ cite journal|title=Embedding Theorems for Groups|journal=Jornal of the London Mathematical… …
83Classification of finite simple groups — Group theory Group theory …
84Algebraic topology — is a branch of mathematics which uses tools from abstract algebra to study topological spaces. The basic goal is to find algebraic invariants that classify topological spaces up to homeomorphism. In many situations this is too much to hope for… …
85Ring (mathematics) — This article is about algebraic structures. For geometric rings, see Annulus (mathematics). For the set theory concept, see Ring of sets. Polynomials, represented here by curves, form a ring under addition and multiplication. In mathematics, a… …
86General linear group — Group theory Group theory …
87Whitehead torsion — In mathematics, Whitehead torsion is an invariant of an h cobordism in a Whitehead group, that is important in simple homotopy theory and surgery theory. It is named for J. H. C. Whitehead.Whitehead torsionSuppose that W is an h cobordism from M… …
88Shockwave (Transformers) — Shockwave is the name of several fictional characters in the various Transformers universes. Due to issues with Hasbro s trademark of the name Shockwave, some products were also released under the name Shockblast.Transformers: Generation… …
89Ramjet (Transformers) — Ramjet is the name of several fictional characters in the various Transformers universes. All have been Decepticon aligned characters who turn into jets. Transformers: Generation 1Transformers character name =Ramjet caption = affiliation… …
90Algebraic K-theory — In mathematics, algebraic K theory is an important part of homological algebra concerned with defining and applying a sequence Kn(R) of functors from rings to abelian groups, for all integers n. For historical reasons, the lower K groups K0 and… …
