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 r354505 = x;
        double r354506 = 1.0;
        double r354507 = r354505 + r354506;
        double r354508 = sqrt(r354507);
        double r354509 = sqrt(r354505);
        double r354510 = r354508 - r354509;
        double r354511 = y;
        double r354512 = r354511 + r354506;
        double r354513 = sqrt(r354512);
        double r354514 = sqrt(r354511);
        double r354515 = r354513 - r354514;
        double r354516 = r354510 + r354515;
        double r354517 = z;
        double r354518 = r354517 + r354506;
        double r354519 = sqrt(r354518);
        double r354520 = sqrt(r354517);
        double r354521 = r354519 - r354520;
        double r354522 = r354516 + r354521;
        double r354523 = t;
        double r354524 = r354523 + r354506;
        double r354525 = sqrt(r354524);
        double r354526 = sqrt(r354523);
        double r354527 = r354525 - r354526;
        double r354528 = r354522 + r354527;
        return r354528;
}