“…Let [a, b] be a nonzero commutator in the lowest dimension, say m. Since H * (G; F p ) is associative, it follows that a and b are generators and [a, b] is primitive. Then by Theorem 5.4.1 (c) of [6], the m must be odd, and hence, we may assume that a is an even-dimensional generator and b is an odd-dimensional generator. Let us dualize the situation: Let u and v be the dual primitive elements to a and b, and choose x to be a generator such that x, [a, b] = 0.…”