Exercise 6, § 11

Let M be a graded A-module of type N. Define a skew graded bigebra structure on the universal anticommutative algebra $G(M)$ (§ 7, Exercise 13); deduce a canonical graded algebra homomorphism $G(M^*) \to G(M)^{*gr}$ and notions of inner product between elements of $G(M)$ and elements of $G(M^*)$.