 Furthermore, if the principal minors of the matrix formula_15 are all positive (known as the Hawkins–Simon condition), the required output vector formula_11 is non-negative.Consider an economy with two goods, A and B.The matrix of coefficients and the final demand is given by

Intuitively, this corresponds to finding the amount of output each sector should produce given that we want 7 units of good A and 4 units of good B.