works_for (finance_manager, director).
works_for (administration_manager, director).
works_for (production_manager, director).
works_for (finance_officer, finance_manager).
works_for (clerk, finance_officer).
works_for (cashier, finance_officer).
works_for (receptionist, administration_manager).
works_for (typist, administration_manager).
works_for (telephonist, administration_manager).
works_for (sales_officer, production_manager).
works_for (stores_manager, production_manager).
works_for (publicity_officer, production_manager).

boss_of (Boss,Worker) :- works_for (Worker, Boss).

under (Worker, Boss) :- works_for (Worker,Boss).
under (Worker, Boss) :- works_for (Worker, Worker2), under (Worker2,Boss).