**nondiagonal** — adj., n.; nondiagonally, adv. * * * … Universalium

**nondiagonal** — adj., n.; nondiagonally, adv … Useful english dictionary

**Coxeter group** — In mathematics, a Coxeter group, named after H.S.M. Coxeter, is an abstract group that admits a formal description in terms of mirror symmetries. Indeed, the finite Coxeter groups are precisely the finite Euclidean reflection groups; the symmetry … Wikipedia

**Ritz method** — In physics, the Ritz method is a variational method named after Walter Ritz.In quantum mechanics, a system of particles can be described in terms of an energy functional or Hamiltonian, which will measure the energy of any proposed configuration… … Wikipedia

**Digraph (mathematics)** — A directed graph or digraph G is an ordered pair G := (V, A) with * V is a set, whose elements are called vertices or nodes, * A is a set of ordered pairs of vertices, called directed edges, arcs, or arrows.It differs from an ordinary, undirected … Wikipedia

**Directed graph** — A directed graph. A directed graph or digraph is a pair G = (V,A) (sometimes G = (V,E)) of:[1] a set V, whose elements are called vertices or … Wikipedia

**Dynkin diagram** — See also: Coxeter–Dynkin diagram Finite Dynkin diagrams Affine (extended) Dynkin diagrams … Wikipedia