variables
  x[3] in (0; 0; 0);

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

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