“…where the second to the last inclusion holds by multihomogeneity and the last inclusion holds by Propositions 4.2, 4.3, and [GS,Theorem 5.2]. Proof: Without loss of generality we may assume that M is in the normalized form so that in the first two rows all the coefficients are 1, and also the coefficients in the first and the last columns are all 1.…”