strategic(X1) v strategic(X2) v strategic(X3) v strategic(X4) :- produced_by(X,X1,X2,X3,X4).
strategic(W) :- controlled_by(W,X1,X2,X3,X4), strategic(X1), strategic(X2), strategic(X3), strategic(X4).

:- query(C1,C2), not strategic(C1).
:- query(C1,C2), not strategic(C2).