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 r493443 = x;
        double r493444 = 1.0;
        double r493445 = r493443 + r493444;
        double r493446 = sqrt(r493445);
        double r493447 = sqrt(r493443);
        double r493448 = r493446 - r493447;
        double r493449 = y;
        double r493450 = r493449 + r493444;
        double r493451 = sqrt(r493450);
        double r493452 = sqrt(r493449);
        double r493453 = r493451 - r493452;
        double r493454 = r493448 + r493453;
        double r493455 = z;
        double r493456 = r493455 + r493444;
        double r493457 = sqrt(r493456);
        double r493458 = sqrt(r493455);
        double r493459 = r493457 - r493458;
        double r493460 = r493454 + r493459;
        double r493461 = t;
        double r493462 = r493461 + r493444;
        double r493463 = sqrt(r493462);
        double r493464 = sqrt(r493461);
        double r493465 = r493463 - r493464;
        double r493466 = r493460 + r493465;
        return r493466;
}