The bald eagle needs the lion. The bear chases the bald eagle. The cat needs the lion. The lion needs the bear. If something is young then it visits the lion. If something needs the lion then it chases the cat. If something chases the lion and the lion visits the cat then the cat is rough. If something needs the bear and it visits the lion then it does not visit the bear. If the lion is rough then the lion does not visit the bald eagle. If something visits the cat and it does not chase the cat then it is not rough.
The bald eagle needs the lion.