Suppose that x ∈ ker(A−λj I )αj . Since αj ≤ n, we have (A−λj I )2n−l x = 0 for all l = 0, . . . , n − 1. This implies (L − λj I )2n x = 0. Since L is diagonalizable, we it follows that (L − λj I )x = 0. Thus, we conclude that Lx = λj x for all vectors x ∈ ker(A − λj I )αj and all j = 1, . . . , m.
Since