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 r362708 = x;
        double r362709 = 1.0;
        double r362710 = r362708 + r362709;
        double r362711 = sqrt(r362710);
        double r362712 = sqrt(r362708);
        double r362713 = r362711 - r362712;
        double r362714 = y;
        double r362715 = r362714 + r362709;
        double r362716 = sqrt(r362715);
        double r362717 = sqrt(r362714);
        double r362718 = r362716 - r362717;
        double r362719 = r362713 + r362718;
        double r362720 = z;
        double r362721 = r362720 + r362709;
        double r362722 = sqrt(r362721);
        double r362723 = sqrt(r362720);
        double r362724 = r362722 - r362723;
        double r362725 = r362719 + r362724;
        double r362726 = t;
        double r362727 = r362726 + r362709;
        double r362728 = sqrt(r362727);
        double r362729 = sqrt(r362726);
        double r362730 = r362728 - r362729;
        double r362731 = r362725 + r362730;
        return r362731;
}