A set of n vector-quantities in an n-dimensional vector space which form an ortho-normal basis, the n vector-quantities are linearly independent and the scalar product of any two is the identity-scalar.
(=> (Orthonormal-Basis ?B)
(And (Forall (?N)
(=> (And (Positive-Integer ?N)
(=< ?N (Basis.Dimension ?B)))
(Defined (Basis.Vec ?B ?N))))
(Forall (?N1 ?N2)
(=> (And (Positive-Integer ?N1)
(Positive-Integer ?N2)
(=< ?N1 (Basis.Dimension ?B))
(=< ?N2 (Basis.Dimension ?B)))
(=> (= ?N1 ?N2)
(= (Dot (Basis.Vec ?B ?N1)
(Basis.Vec ?B ?N2))
1))
(=> (/= ?N1 ?N2)
(= (Dot (Basis.Vec ?B ?N1)
(Basis.Vec ?B ?N2))
0))))))