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 r331726 = x;
        double r331727 = 1.0;
        double r331728 = r331726 + r331727;
        double r331729 = sqrt(r331728);
        double r331730 = sqrt(r331726);
        double r331731 = r331729 - r331730;
        double r331732 = y;
        double r331733 = r331732 + r331727;
        double r331734 = sqrt(r331733);
        double r331735 = sqrt(r331732);
        double r331736 = r331734 - r331735;
        double r331737 = r331731 + r331736;
        double r331738 = z;
        double r331739 = r331738 + r331727;
        double r331740 = sqrt(r331739);
        double r331741 = sqrt(r331738);
        double r331742 = r331740 - r331741;
        double r331743 = r331737 + r331742;
        double r331744 = t;
        double r331745 = r331744 + r331727;
        double r331746 = sqrt(r331745);
        double r331747 = sqrt(r331744);
        double r331748 = r331746 - r331747;
        double r331749 = r331743 + r331748;
        return r331749;
}