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 r570196 = x;
        double r570197 = 1.0;
        double r570198 = r570196 + r570197;
        double r570199 = sqrt(r570198);
        double r570200 = sqrt(r570196);
        double r570201 = r570199 - r570200;
        double r570202 = y;
        double r570203 = r570202 + r570197;
        double r570204 = sqrt(r570203);
        double r570205 = sqrt(r570202);
        double r570206 = r570204 - r570205;
        double r570207 = r570201 + r570206;
        double r570208 = z;
        double r570209 = r570208 + r570197;
        double r570210 = sqrt(r570209);
        double r570211 = sqrt(r570208);
        double r570212 = r570210 - r570211;
        double r570213 = r570207 + r570212;
        double r570214 = t;
        double r570215 = r570214 + r570197;
        double r570216 = sqrt(r570215);
        double r570217 = sqrt(r570214);
        double r570218 = r570216 - r570217;
        double r570219 = r570213 + r570218;
        return r570219;
}