Cannot sample enough valid points. (more)

\[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\]
\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
double f(double x, double y, double z, double t) {
        double r550760 = x;
        double r550761 = 1.0;
        double r550762 = r550760 + r550761;
        double r550763 = sqrt(r550762);
        double r550764 = sqrt(r550760);
        double r550765 = r550763 - r550764;
        double r550766 = y;
        double r550767 = r550766 + r550761;
        double r550768 = sqrt(r550767);
        double r550769 = sqrt(r550766);
        double r550770 = r550768 - r550769;
        double r550771 = r550765 + r550770;
        double r550772 = z;
        double r550773 = r550772 + r550761;
        double r550774 = sqrt(r550773);
        double r550775 = sqrt(r550772);
        double r550776 = r550774 - r550775;
        double r550777 = r550771 + r550776;
        double r550778 = t;
        double r550779 = r550778 + r550761;
        double r550780 = sqrt(r550779);
        double r550781 = sqrt(r550778);
        double r550782 = r550780 - r550781;
        double r550783 = r550777 + r550782;
        return r550783;
}