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 r498338 = x;
        double r498339 = 1.0;
        double r498340 = r498338 + r498339;
        double r498341 = sqrt(r498340);
        double r498342 = sqrt(r498338);
        double r498343 = r498341 - r498342;
        double r498344 = y;
        double r498345 = r498344 + r498339;
        double r498346 = sqrt(r498345);
        double r498347 = sqrt(r498344);
        double r498348 = r498346 - r498347;
        double r498349 = r498343 + r498348;
        double r498350 = z;
        double r498351 = r498350 + r498339;
        double r498352 = sqrt(r498351);
        double r498353 = sqrt(r498350);
        double r498354 = r498352 - r498353;
        double r498355 = r498349 + r498354;
        double r498356 = t;
        double r498357 = r498356 + r498339;
        double r498358 = sqrt(r498357);
        double r498359 = sqrt(r498356);
        double r498360 = r498358 - r498359;
        double r498361 = r498355 + r498360;
        return r498361;
}