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 r435935 = x;
        double r435936 = 1.0;
        double r435937 = r435935 + r435936;
        double r435938 = sqrt(r435937);
        double r435939 = sqrt(r435935);
        double r435940 = r435938 - r435939;
        double r435941 = y;
        double r435942 = r435941 + r435936;
        double r435943 = sqrt(r435942);
        double r435944 = sqrt(r435941);
        double r435945 = r435943 - r435944;
        double r435946 = r435940 + r435945;
        double r435947 = z;
        double r435948 = r435947 + r435936;
        double r435949 = sqrt(r435948);
        double r435950 = sqrt(r435947);
        double r435951 = r435949 - r435950;
        double r435952 = r435946 + r435951;
        double r435953 = t;
        double r435954 = r435953 + r435936;
        double r435955 = sqrt(r435954);
        double r435956 = sqrt(r435953);
        double r435957 = r435955 - r435956;
        double r435958 = r435952 + r435957;
        return r435958;
}