[x1, x2, x3, x4, x5, x6, x7, x8] x1^2 - x2^2 - x3^2 - x4^2 - x5^2 - x6^2 - x7^2 - x8^2; 2*x1*x2; 2*x1*x3; 2*x1*x4; 2*x1*x5; 2*x1*x6; 2*x1*x7; 2*x1*x8; [[0.01, 10], [-0.01, 10], [-0.01, 10], [-0.01, 10], [-0.01, 10], [-0.01, 10], [-0.01, 10], [-0.01, 10]] # This function has a unique zero f(0)=0, but the box does NOT contain zero (see the first component), so the degree is zero.