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 r365905 = x;
        double r365906 = 1.0;
        double r365907 = r365905 + r365906;
        double r365908 = sqrt(r365907);
        double r365909 = sqrt(r365905);
        double r365910 = r365908 - r365909;
        double r365911 = y;
        double r365912 = r365911 + r365906;
        double r365913 = sqrt(r365912);
        double r365914 = sqrt(r365911);
        double r365915 = r365913 - r365914;
        double r365916 = r365910 + r365915;
        double r365917 = z;
        double r365918 = r365917 + r365906;
        double r365919 = sqrt(r365918);
        double r365920 = sqrt(r365917);
        double r365921 = r365919 - r365920;
        double r365922 = r365916 + r365921;
        double r365923 = t;
        double r365924 = r365923 + r365906;
        double r365925 = sqrt(r365924);
        double r365926 = sqrt(r365923);
        double r365927 = r365925 - r365926;
        double r365928 = r365922 + r365927;
        return r365928;
}