Exercise 9.9 Show that if and are contrasts and that if = 0, then = 0 and

Exercise 9.9 Show that if ξ τ and ητ are contrasts and that if ξ η = 0, then

ξ τ = 0 and ητ = 0 put orthogonal constraints on C(X,Z), i.e., the treatment sum of squares can be broken down with orthogonal contrasts in the usual way.