By taking transpose of the tensor momentum equation, one sees that the role of Λ Λ ∗ ∗ and Ω Ω ∗ ∗ are interchanged. If there is solution for A , Λ Λ ∗ ∗ , Ω Ω ∗ ∗ , then for the same A , there exists another solution with the role of Λ Λ ∗ ∗ and Ω Ω ∗ ∗ interchanged. But interchanging Λ Λ ∗ ∗ and Ω Ω ∗ ∗ is equivalent to replacing P by P T . The following relations confirms the previous statement.