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 r19954949 = x;
        double r19954950 = 1.0;
        double r19954951 = r19954949 + r19954950;
        double r19954952 = sqrt(r19954951);
        double r19954953 = sqrt(r19954949);
        double r19954954 = r19954952 - r19954953;
        double r19954955 = y;
        double r19954956 = r19954955 + r19954950;
        double r19954957 = sqrt(r19954956);
        double r19954958 = sqrt(r19954955);
        double r19954959 = r19954957 - r19954958;
        double r19954960 = r19954954 + r19954959;
        double r19954961 = z;
        double r19954962 = r19954961 + r19954950;
        double r19954963 = sqrt(r19954962);
        double r19954964 = sqrt(r19954961);
        double r19954965 = r19954963 - r19954964;
        double r19954966 = r19954960 + r19954965;
        double r19954967 = t;
        double r19954968 = r19954967 + r19954950;
        double r19954969 = sqrt(r19954968);
        double r19954970 = sqrt(r19954967);
        double r19954971 = r19954969 - r19954970;
        double r19954972 = r19954966 + r19954971;
        return r19954972;
}