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 r458280 = x;
        double r458281 = 1.0;
        double r458282 = r458280 + r458281;
        double r458283 = sqrt(r458282);
        double r458284 = sqrt(r458280);
        double r458285 = r458283 - r458284;
        double r458286 = y;
        double r458287 = r458286 + r458281;
        double r458288 = sqrt(r458287);
        double r458289 = sqrt(r458286);
        double r458290 = r458288 - r458289;
        double r458291 = r458285 + r458290;
        double r458292 = z;
        double r458293 = r458292 + r458281;
        double r458294 = sqrt(r458293);
        double r458295 = sqrt(r458292);
        double r458296 = r458294 - r458295;
        double r458297 = r458291 + r458296;
        double r458298 = t;
        double r458299 = r458298 + r458281;
        double r458300 = sqrt(r458299);
        double r458301 = sqrt(r458298);
        double r458302 = r458300 - r458301;
        double r458303 = r458297 + r458302;
        return r458303;
}