Definition (Orthonormal vector)
Two vectors in a vector space are said to be orthonormal if they are orthogonal unit vectors (i.e., with norm equal to ).
Definition (Orthonormal set)
A set of vectors in a vector space is orthonormal if all elements of this set are orthonormal to each other.
Proposition (2.3.1)
A sequence of orthonormal vectors is a linearly independent collection.