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 r384594 = x;
        double r384595 = 1.0;
        double r384596 = r384594 + r384595;
        double r384597 = sqrt(r384596);
        double r384598 = sqrt(r384594);
        double r384599 = r384597 - r384598;
        double r384600 = y;
        double r384601 = r384600 + r384595;
        double r384602 = sqrt(r384601);
        double r384603 = sqrt(r384600);
        double r384604 = r384602 - r384603;
        double r384605 = r384599 + r384604;
        double r384606 = z;
        double r384607 = r384606 + r384595;
        double r384608 = sqrt(r384607);
        double r384609 = sqrt(r384606);
        double r384610 = r384608 - r384609;
        double r384611 = r384605 + r384610;
        double r384612 = t;
        double r384613 = r384612 + r384595;
        double r384614 = sqrt(r384613);
        double r384615 = sqrt(r384612);
        double r384616 = r384614 - r384615;
        double r384617 = r384611 + r384616;
        return r384617;
}