function xdot=vss_eu2(t,x)
%This file is used by the script EX_6_2m

% last modified by S. H. Zak on December 2, 2002

%u=-2*sign(x(1)+x(2));
%approximating the sign function in the controller
mu=0.001;
sigma=x(1)+x(2);
u=-2*sigma/(abs(sigma)+mu);
xdot=[x(2);u];