pot_del_organization(O,N,Ci,Co,P,E) :- ext_del_organization(O,N,Ci,Co,P,E),
        organization(O,N,Ci,Co,P,E).
% refs from isMember to Country and Organization: ON DELETE CASCADE.
pot_del_isMember(C,O,T) :- pot_del_country(N,C,Cap,CapP,A,Pop),
        isMember(C,O,T).
pot_del_isMember(C,O,T) :- pot_del_organization(O,N,Ci,Co,P,E),
        isMember(C,O,T).