function c = cstr(x)
% example for the CSTR in Ex.2.3.
%

eta0 = 1.75; etac = 1.75;
U1 = 2.0;

c(1) = 1 - x(1) - x(1)*exp(50*(0.5-1/x(2)));
c(2) = (eta0-x(2)) - U1*(x(2)-etac) + x(1)*exp(50*(0.5-1/x(2)));
