Complexity of additive computations of systems of linear forms

The additive computation of a system of linear forms can be represented by a sequence of square matrices Q₁,...,Q_T (Q_i equals the identity matrix increased or decreased by 1 in one entry). The complexity of the additive computation is the minimal number of matrices in such a representation. A connection between the additive complexity of a system with coefficient matrix A and of a system with coefficient matrix A^T is proved.