-- Haskell provides a standard function, last :: [a] -> a, that returns the last
-- element of a list. From reading the type alone, what are the possible valid
-- behaviours (omitting crashes and infinite loops) that this function could
-- have? What are a few things that this function clearly cannot do?

-- Possible valid behaviours could be
--   - returning the first element of the list
--   - returning an element in the middle of the list
--   - returning the last element of the list
--   ...

-- This function clearly cannot
--   - return an element of the list at a specified index because it has just
--     one parameter
--   - return a sublist of the list
--   - be an identity function (return its argument)
--   ...