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 r770082 = x;
        double r770083 = 1.0;
        double r770084 = r770082 + r770083;
        double r770085 = sqrt(r770084);
        double r770086 = sqrt(r770082);
        double r770087 = r770085 - r770086;
        double r770088 = y;
        double r770089 = r770088 + r770083;
        double r770090 = sqrt(r770089);
        double r770091 = sqrt(r770088);
        double r770092 = r770090 - r770091;
        double r770093 = r770087 + r770092;
        double r770094 = z;
        double r770095 = r770094 + r770083;
        double r770096 = sqrt(r770095);
        double r770097 = sqrt(r770094);
        double r770098 = r770096 - r770097;
        double r770099 = r770093 + r770098;
        double r770100 = t;
        double r770101 = r770100 + r770083;
        double r770102 = sqrt(r770101);
        double r770103 = sqrt(r770100);
        double r770104 = r770102 - r770103;
        double r770105 = r770099 + r770104;
        return r770105;
}