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 r355179 = x;
        double r355180 = 1.0;
        double r355181 = r355179 + r355180;
        double r355182 = sqrt(r355181);
        double r355183 = sqrt(r355179);
        double r355184 = r355182 - r355183;
        double r355185 = y;
        double r355186 = r355185 + r355180;
        double r355187 = sqrt(r355186);
        double r355188 = sqrt(r355185);
        double r355189 = r355187 - r355188;
        double r355190 = r355184 + r355189;
        double r355191 = z;
        double r355192 = r355191 + r355180;
        double r355193 = sqrt(r355192);
        double r355194 = sqrt(r355191);
        double r355195 = r355193 - r355194;
        double r355196 = r355190 + r355195;
        double r355197 = t;
        double r355198 = r355197 + r355180;
        double r355199 = sqrt(r355198);
        double r355200 = sqrt(r355197);
        double r355201 = r355199 - r355200;
        double r355202 = r355196 + r355201;
        return r355202;
}