Hi,
 
1) How can I hide an instance of a class imported from prelude? For example I would like to redefine
 
instance (Ord a, Ord b) => Ord (a,b) where
 (<=) (x,y) (z,w)
  | x < z = True
  | x == z = if y <= w then True else False
  | otherwise = False
 
for educational purposes.
 
2) I could not find an entry for this instance in Prelude instead I found
 

instance Ord () where

compare () () = EQ

 
Is this suppose to mean "for all tuples"?
 
How do I define functions that work on all tuples?
 
Thanks for taking time