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 r546262 = x;
        double r546263 = 1.0;
        double r546264 = r546262 + r546263;
        double r546265 = sqrt(r546264);
        double r546266 = sqrt(r546262);
        double r546267 = r546265 - r546266;
        double r546268 = y;
        double r546269 = r546268 + r546263;
        double r546270 = sqrt(r546269);
        double r546271 = sqrt(r546268);
        double r546272 = r546270 - r546271;
        double r546273 = r546267 + r546272;
        double r546274 = z;
        double r546275 = r546274 + r546263;
        double r546276 = sqrt(r546275);
        double r546277 = sqrt(r546274);
        double r546278 = r546276 - r546277;
        double r546279 = r546273 + r546278;
        double r546280 = t;
        double r546281 = r546280 + r546263;
        double r546282 = sqrt(r546281);
        double r546283 = sqrt(r546280);
        double r546284 = r546282 - r546283;
        double r546285 = r546279 + r546284;
        return r546285;
}