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 r374351 = x;
        double r374352 = 1.0;
        double r374353 = r374351 + r374352;
        double r374354 = sqrt(r374353);
        double r374355 = sqrt(r374351);
        double r374356 = r374354 - r374355;
        double r374357 = y;
        double r374358 = r374357 + r374352;
        double r374359 = sqrt(r374358);
        double r374360 = sqrt(r374357);
        double r374361 = r374359 - r374360;
        double r374362 = r374356 + r374361;
        double r374363 = z;
        double r374364 = r374363 + r374352;
        double r374365 = sqrt(r374364);
        double r374366 = sqrt(r374363);
        double r374367 = r374365 - r374366;
        double r374368 = r374362 + r374367;
        double r374369 = t;
        double r374370 = r374369 + r374352;
        double r374371 = sqrt(r374370);
        double r374372 = sqrt(r374369);
        double r374373 = r374371 - r374372;
        double r374374 = r374368 + r374373;
        return r374374;
}