... matrices A1 , A2 , , Ak such that all of the following conditions hold: (1) A2 = A2 = = A2 = 0, k (2) Ai Aj = Aj Ai for all ≤ i, j ≤ k, and (3) A1 A2 Ak = Solution The anwser is nk = 2k In ... i ∈ S for all i = 1, 2, , k and S ⊂ {1, 2, , k} Then A2 = and Ai Aj = Aj Ai Furthermore, i A1 A2 Ak [∅] = [{1, 2, , k}], and hence A1 A2 Ak = Now let A1 , A2 , , Ak be n × n ... can be constructed as follows: Let V be the n-dimensional real vector space with basis elements [S], where S runs through all n = 2k subsets of {1, 2, , k} Define Ai as an endomorphism of V...