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 r310364 = x;
        double r310365 = 1.0;
        double r310366 = r310364 + r310365;
        double r310367 = sqrt(r310366);
        double r310368 = sqrt(r310364);
        double r310369 = r310367 - r310368;
        double r310370 = y;
        double r310371 = r310370 + r310365;
        double r310372 = sqrt(r310371);
        double r310373 = sqrt(r310370);
        double r310374 = r310372 - r310373;
        double r310375 = r310369 + r310374;
        double r310376 = z;
        double r310377 = r310376 + r310365;
        double r310378 = sqrt(r310377);
        double r310379 = sqrt(r310376);
        double r310380 = r310378 - r310379;
        double r310381 = r310375 + r310380;
        double r310382 = t;
        double r310383 = r310382 + r310365;
        double r310384 = sqrt(r310383);
        double r310385 = sqrt(r310382);
        double r310386 = r310384 - r310385;
        double r310387 = r310381 + r310386;
        return r310387;
}