reconsider S = {{}} as Subset-Family of X by SETFAM_1:61;
take S ; :: thesis: ( not S is empty & S is V47() )
thus not S is empty ; :: thesis: S is V47()
{} is Subset of X by XBOOLE_1:2;
hence ( S is empty or ex F being Function of NAT,(bool X) st S = rng F ) by Th34; :: according to SUPINF_2:def 14 :: thesis: verum