module Database (
  Database, 
  newDB,        -- Ord a => Database a
  insertItemDB, -- Ord a => Database a -> a -> Database a
  deleteItemDB, -- Ord a => Database a -> a  -> Database a
  searchDB      -- Ord a => Database a -> (a -> Bool) -> [a]
                -- 'search db p' returns all entries e of the 
                --  data base for which 'p e' evaluates to 'True'
) where


type Database a = [a]