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 r326884 = x;
        double r326885 = 1.0;
        double r326886 = r326884 + r326885;
        double r326887 = sqrt(r326886);
        double r326888 = sqrt(r326884);
        double r326889 = r326887 - r326888;
        double r326890 = y;
        double r326891 = r326890 + r326885;
        double r326892 = sqrt(r326891);
        double r326893 = sqrt(r326890);
        double r326894 = r326892 - r326893;
        double r326895 = r326889 + r326894;
        double r326896 = z;
        double r326897 = r326896 + r326885;
        double r326898 = sqrt(r326897);
        double r326899 = sqrt(r326896);
        double r326900 = r326898 - r326899;
        double r326901 = r326895 + r326900;
        double r326902 = t;
        double r326903 = r326902 + r326885;
        double r326904 = sqrt(r326903);
        double r326905 = sqrt(r326902);
        double r326906 = r326904 - r326905;
        double r326907 = r326901 + r326906;
        return r326907;
}