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 r466504 = x;
        double r466505 = 1.0;
        double r466506 = r466504 + r466505;
        double r466507 = sqrt(r466506);
        double r466508 = sqrt(r466504);
        double r466509 = r466507 - r466508;
        double r466510 = y;
        double r466511 = r466510 + r466505;
        double r466512 = sqrt(r466511);
        double r466513 = sqrt(r466510);
        double r466514 = r466512 - r466513;
        double r466515 = r466509 + r466514;
        double r466516 = z;
        double r466517 = r466516 + r466505;
        double r466518 = sqrt(r466517);
        double r466519 = sqrt(r466516);
        double r466520 = r466518 - r466519;
        double r466521 = r466515 + r466520;
        double r466522 = t;
        double r466523 = r466522 + r466505;
        double r466524 = sqrt(r466523);
        double r466525 = sqrt(r466522);
        double r466526 = r466524 - r466525;
        double r466527 = r466521 + r466526;
        return r466527;
}