variables
  x[6] in (0; 0; 0; 0; 0; 0);

function f(x[6])
  return(x(1)*(-1 + x(1)*x(2)*x(3)*x(4)*x(5)*x(6)); x(2)*(-1 + x(1)*x(2)*x(3)*x(4)*x(5)*x(6)); x(3)*(-1 + x(1)*x(2)*x(3)*x(4)*x(5)*x(6)); x(4)*(-1 + x(1)*x(2)*x(3)*x(4)*x(5)*x(6)); x(5)*(-1 + x(1)*x(2)*x(3)*x(4)*x(5)*x(6)); x(6)*(-1 + x(1)*x(2)*x(3)*x(4)*x(5)*x(6)));
end

function v(u[6])
  return(u(1)^2 + u(2)^2 + u(3)^2 + u(4)^2 + u(5)^2 + u(6)^2);
end