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 r20498703 = x;
        double r20498704 = 1.0;
        double r20498705 = r20498703 + r20498704;
        double r20498706 = sqrt(r20498705);
        double r20498707 = sqrt(r20498703);
        double r20498708 = r20498706 - r20498707;
        double r20498709 = y;
        double r20498710 = r20498709 + r20498704;
        double r20498711 = sqrt(r20498710);
        double r20498712 = sqrt(r20498709);
        double r20498713 = r20498711 - r20498712;
        double r20498714 = r20498708 + r20498713;
        double r20498715 = z;
        double r20498716 = r20498715 + r20498704;
        double r20498717 = sqrt(r20498716);
        double r20498718 = sqrt(r20498715);
        double r20498719 = r20498717 - r20498718;
        double r20498720 = r20498714 + r20498719;
        double r20498721 = t;
        double r20498722 = r20498721 + r20498704;
        double r20498723 = sqrt(r20498722);
        double r20498724 = sqrt(r20498721);
        double r20498725 = r20498723 - r20498724;
        double r20498726 = r20498720 + r20498725;
        return r20498726;
}