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 r474985 = x;
        double r474986 = 1.0;
        double r474987 = r474985 + r474986;
        double r474988 = sqrt(r474987);
        double r474989 = sqrt(r474985);
        double r474990 = r474988 - r474989;
        double r474991 = y;
        double r474992 = r474991 + r474986;
        double r474993 = sqrt(r474992);
        double r474994 = sqrt(r474991);
        double r474995 = r474993 - r474994;
        double r474996 = r474990 + r474995;
        double r474997 = z;
        double r474998 = r474997 + r474986;
        double r474999 = sqrt(r474998);
        double r475000 = sqrt(r474997);
        double r475001 = r474999 - r475000;
        double r475002 = r474996 + r475001;
        double r475003 = t;
        double r475004 = r475003 + r474986;
        double r475005 = sqrt(r475004);
        double r475006 = sqrt(r475003);
        double r475007 = r475005 - r475006;
        double r475008 = r475002 + r475007;
        return r475008;
}