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 r570616 = x;
        double r570617 = 1.0;
        double r570618 = r570616 + r570617;
        double r570619 = sqrt(r570618);
        double r570620 = sqrt(r570616);
        double r570621 = r570619 - r570620;
        double r570622 = y;
        double r570623 = r570622 + r570617;
        double r570624 = sqrt(r570623);
        double r570625 = sqrt(r570622);
        double r570626 = r570624 - r570625;
        double r570627 = r570621 + r570626;
        double r570628 = z;
        double r570629 = r570628 + r570617;
        double r570630 = sqrt(r570629);
        double r570631 = sqrt(r570628);
        double r570632 = r570630 - r570631;
        double r570633 = r570627 + r570632;
        double r570634 = t;
        double r570635 = r570634 + r570617;
        double r570636 = sqrt(r570635);
        double r570637 = sqrt(r570634);
        double r570638 = r570636 - r570637;
        double r570639 = r570633 + r570638;
        return r570639;
}