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 r287202 = x;
        double r287203 = 1.0;
        double r287204 = r287202 + r287203;
        double r287205 = sqrt(r287204);
        double r287206 = sqrt(r287202);
        double r287207 = r287205 - r287206;
        double r287208 = y;
        double r287209 = r287208 + r287203;
        double r287210 = sqrt(r287209);
        double r287211 = sqrt(r287208);
        double r287212 = r287210 - r287211;
        double r287213 = r287207 + r287212;
        double r287214 = z;
        double r287215 = r287214 + r287203;
        double r287216 = sqrt(r287215);
        double r287217 = sqrt(r287214);
        double r287218 = r287216 - r287217;
        double r287219 = r287213 + r287218;
        double r287220 = t;
        double r287221 = r287220 + r287203;
        double r287222 = sqrt(r287221);
        double r287223 = sqrt(r287220);
        double r287224 = r287222 - r287223;
        double r287225 = r287219 + r287224;
        return r287225;
}