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 r482905 = x;
        double r482906 = 1.0;
        double r482907 = r482905 + r482906;
        double r482908 = sqrt(r482907);
        double r482909 = sqrt(r482905);
        double r482910 = r482908 - r482909;
        double r482911 = y;
        double r482912 = r482911 + r482906;
        double r482913 = sqrt(r482912);
        double r482914 = sqrt(r482911);
        double r482915 = r482913 - r482914;
        double r482916 = r482910 + r482915;
        double r482917 = z;
        double r482918 = r482917 + r482906;
        double r482919 = sqrt(r482918);
        double r482920 = sqrt(r482917);
        double r482921 = r482919 - r482920;
        double r482922 = r482916 + r482921;
        double r482923 = t;
        double r482924 = r482923 + r482906;
        double r482925 = sqrt(r482924);
        double r482926 = sqrt(r482923);
        double r482927 = r482925 - r482926;
        double r482928 = r482922 + r482927;
        return r482928;
}