-- Write code which takes two lists as input and decides whether list1 if a prefix of list2, meaning list2 begins exactly with list1. The top-level function must have the type declaration isPrefix :: Eq a => [a] -> [a] -> Bool
isPrefix :: Eq a => [a] -> [a] -> Bool
isPrefix [] [] = True
isPrefix xs [] = False
isPrefix [] ys = True
isPrefix (x:xs) (y:ys)
	| x == y = isPrefix xs ys
	| otherwise = False