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 r484015 = x;
        double r484016 = 1.0;
        double r484017 = r484015 + r484016;
        double r484018 = sqrt(r484017);
        double r484019 = sqrt(r484015);
        double r484020 = r484018 - r484019;
        double r484021 = y;
        double r484022 = r484021 + r484016;
        double r484023 = sqrt(r484022);
        double r484024 = sqrt(r484021);
        double r484025 = r484023 - r484024;
        double r484026 = r484020 + r484025;
        double r484027 = z;
        double r484028 = r484027 + r484016;
        double r484029 = sqrt(r484028);
        double r484030 = sqrt(r484027);
        double r484031 = r484029 - r484030;
        double r484032 = r484026 + r484031;
        double r484033 = t;
        double r484034 = r484033 + r484016;
        double r484035 = sqrt(r484034);
        double r484036 = sqrt(r484033);
        double r484037 = r484035 - r484036;
        double r484038 = r484032 + r484037;
        return r484038;
}