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 r462440 = x;
        double r462441 = 1.0;
        double r462442 = r462440 + r462441;
        double r462443 = sqrt(r462442);
        double r462444 = sqrt(r462440);
        double r462445 = r462443 - r462444;
        double r462446 = y;
        double r462447 = r462446 + r462441;
        double r462448 = sqrt(r462447);
        double r462449 = sqrt(r462446);
        double r462450 = r462448 - r462449;
        double r462451 = r462445 + r462450;
        double r462452 = z;
        double r462453 = r462452 + r462441;
        double r462454 = sqrt(r462453);
        double r462455 = sqrt(r462452);
        double r462456 = r462454 - r462455;
        double r462457 = r462451 + r462456;
        double r462458 = t;
        double r462459 = r462458 + r462441;
        double r462460 = sqrt(r462459);
        double r462461 = sqrt(r462458);
        double r462462 = r462460 - r462461;
        double r462463 = r462457 + r462462;
        return r462463;
}