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 r556172 = x;
        double r556173 = 1.0;
        double r556174 = r556172 + r556173;
        double r556175 = sqrt(r556174);
        double r556176 = sqrt(r556172);
        double r556177 = r556175 - r556176;
        double r556178 = y;
        double r556179 = r556178 + r556173;
        double r556180 = sqrt(r556179);
        double r556181 = sqrt(r556178);
        double r556182 = r556180 - r556181;
        double r556183 = r556177 + r556182;
        double r556184 = z;
        double r556185 = r556184 + r556173;
        double r556186 = sqrt(r556185);
        double r556187 = sqrt(r556184);
        double r556188 = r556186 - r556187;
        double r556189 = r556183 + r556188;
        double r556190 = t;
        double r556191 = r556190 + r556173;
        double r556192 = sqrt(r556191);
        double r556193 = sqrt(r556190);
        double r556194 = r556192 - r556193;
        double r556195 = r556189 + r556194;
        return r556195;
}