owns( merlyn, gold ).
owns( ovid, pocketLint ).
owns( ovid, cheapWhiskey ).
owns( kudra, dominationFund ).

valuable( gold ).
valuable( dominationFund ).

thief( badguy ).

rich( X ) :-
  owns( X, Y ),
  valuable( Y ).

steals_from( X, Y ) :-
  thief( X ),
  rich( Y ).