A certain country mainly exports cans of mixed fruit, containing papayas, bananas, and mangoes. The powerful papaya lobby has imposed restrictions on the contents of the cans: they must have at least 10%  papaya and at least half as much papaya as banana. For a certain type of can, suppose the amount of papaya is "p", the amount of mango is "m", and the amount of banana is "b" (all floats). Write a predicate that says whether the can can be legally exported or not.