function y = PrG3c(x)
% Matlab Code by A. Hedar (Nov. 23, 2005).
n = 20;
% Constraints
y(1) = abs(sum(x.^2)-1)-1e-4;
% Variable lower bounds
for j=1:n; y(j+1) = -x(j); end
% Variable upper bounds
for j=1:n; y(j+n+1) = x(j)-1; end
% *************************************************************************
y=y'; 