Orthonormal Basis: Inner Product Space, Vector Unit Vector, Basis (Linear Algebra), Hamel Basis, Hilbert Space

Frame of a Vector Space: Linear Algebra, Inner Product, Basis (linear algebra)

Dimension (vector space): Mathematics, Cardinal Number, Vector Space, Basis (linear algebra)

Unit Vector: Mathematics, Normed Vector Space, Euclidean Vector, Norm, Caret, Dot Product, Basis

Transform Theory: Theory, Basis (Linear Algebra), Vector Space, Spectral Theorem, Self Adjoint