function [dg,dh]=grestr(x)
% Edgar & Himmelblau, 1988
% x0 = [-1, -2]'
% xo = [0.8229, 0.9114]'
% S(xo) = 1.3935

dg=[(1/2 * x(1))  (2 * x(2))];
dh=[ 1  -2];
