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 r498772 = x;
        double r498773 = 1.0;
        double r498774 = r498772 + r498773;
        double r498775 = sqrt(r498774);
        double r498776 = sqrt(r498772);
        double r498777 = r498775 - r498776;
        double r498778 = y;
        double r498779 = r498778 + r498773;
        double r498780 = sqrt(r498779);
        double r498781 = sqrt(r498778);
        double r498782 = r498780 - r498781;
        double r498783 = r498777 + r498782;
        double r498784 = z;
        double r498785 = r498784 + r498773;
        double r498786 = sqrt(r498785);
        double r498787 = sqrt(r498784);
        double r498788 = r498786 - r498787;
        double r498789 = r498783 + r498788;
        double r498790 = t;
        double r498791 = r498790 + r498773;
        double r498792 = sqrt(r498791);
        double r498793 = sqrt(r498790);
        double r498794 = r498792 - r498793;
        double r498795 = r498789 + r498794;
        return r498795;
}