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 r446400 = x;
        double r446401 = 1.0;
        double r446402 = r446400 + r446401;
        double r446403 = sqrt(r446402);
        double r446404 = sqrt(r446400);
        double r446405 = r446403 - r446404;
        double r446406 = y;
        double r446407 = r446406 + r446401;
        double r446408 = sqrt(r446407);
        double r446409 = sqrt(r446406);
        double r446410 = r446408 - r446409;
        double r446411 = r446405 + r446410;
        double r446412 = z;
        double r446413 = r446412 + r446401;
        double r446414 = sqrt(r446413);
        double r446415 = sqrt(r446412);
        double r446416 = r446414 - r446415;
        double r446417 = r446411 + r446416;
        double r446418 = t;
        double r446419 = r446418 + r446401;
        double r446420 = sqrt(r446419);
        double r446421 = sqrt(r446418);
        double r446422 = r446420 - r446421;
        double r446423 = r446417 + r446422;
        return r446423;
}