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 r348593 = x;
        double r348594 = 1.0;
        double r348595 = r348593 + r348594;
        double r348596 = sqrt(r348595);
        double r348597 = sqrt(r348593);
        double r348598 = r348596 - r348597;
        double r348599 = y;
        double r348600 = r348599 + r348594;
        double r348601 = sqrt(r348600);
        double r348602 = sqrt(r348599);
        double r348603 = r348601 - r348602;
        double r348604 = r348598 + r348603;
        double r348605 = z;
        double r348606 = r348605 + r348594;
        double r348607 = sqrt(r348606);
        double r348608 = sqrt(r348605);
        double r348609 = r348607 - r348608;
        double r348610 = r348604 + r348609;
        double r348611 = t;
        double r348612 = r348611 + r348594;
        double r348613 = sqrt(r348612);
        double r348614 = sqrt(r348611);
        double r348615 = r348613 - r348614;
        double r348616 = r348610 + r348615;
        return r348616;
}