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 r373179 = x;
        double r373180 = 1.0;
        double r373181 = r373179 + r373180;
        double r373182 = sqrt(r373181);
        double r373183 = sqrt(r373179);
        double r373184 = r373182 - r373183;
        double r373185 = y;
        double r373186 = r373185 + r373180;
        double r373187 = sqrt(r373186);
        double r373188 = sqrt(r373185);
        double r373189 = r373187 - r373188;
        double r373190 = r373184 + r373189;
        double r373191 = z;
        double r373192 = r373191 + r373180;
        double r373193 = sqrt(r373192);
        double r373194 = sqrt(r373191);
        double r373195 = r373193 - r373194;
        double r373196 = r373190 + r373195;
        double r373197 = t;
        double r373198 = r373197 + r373180;
        double r373199 = sqrt(r373198);
        double r373200 = sqrt(r373197);
        double r373201 = r373199 - r373200;
        double r373202 = r373196 + r373201;
        return r373202;
}