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 r318372 = x;
        double r318373 = 1.0;
        double r318374 = r318372 + r318373;
        double r318375 = sqrt(r318374);
        double r318376 = sqrt(r318372);
        double r318377 = r318375 - r318376;
        double r318378 = y;
        double r318379 = r318378 + r318373;
        double r318380 = sqrt(r318379);
        double r318381 = sqrt(r318378);
        double r318382 = r318380 - r318381;
        double r318383 = r318377 + r318382;
        double r318384 = z;
        double r318385 = r318384 + r318373;
        double r318386 = sqrt(r318385);
        double r318387 = sqrt(r318384);
        double r318388 = r318386 - r318387;
        double r318389 = r318383 + r318388;
        double r318390 = t;
        double r318391 = r318390 + r318373;
        double r318392 = sqrt(r318391);
        double r318393 = sqrt(r318390);
        double r318394 = r318392 - r318393;
        double r318395 = r318389 + r318394;
        return r318395;
}