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 r506037 = x;
        double r506038 = 1.0;
        double r506039 = r506037 + r506038;
        double r506040 = sqrt(r506039);
        double r506041 = sqrt(r506037);
        double r506042 = r506040 - r506041;
        double r506043 = y;
        double r506044 = r506043 + r506038;
        double r506045 = sqrt(r506044);
        double r506046 = sqrt(r506043);
        double r506047 = r506045 - r506046;
        double r506048 = r506042 + r506047;
        double r506049 = z;
        double r506050 = r506049 + r506038;
        double r506051 = sqrt(r506050);
        double r506052 = sqrt(r506049);
        double r506053 = r506051 - r506052;
        double r506054 = r506048 + r506053;
        double r506055 = t;
        double r506056 = r506055 + r506038;
        double r506057 = sqrt(r506056);
        double r506058 = sqrt(r506055);
        double r506059 = r506057 - r506058;
        double r506060 = r506054 + r506059;
        return r506060;
}