--chameleon -d show.ch 

interface Prelude

--class Show a where
--  show :: a->String
--  read :: String->a

-- we've predefined Show, hence,
-- we invent some new names
hconstraint MShow
extern mshow :: MShow a => a->String
extern mread :: MShow a => String->a

g :: MShow a => String -> a -> (String,String)
g s x = (mshow ((mread s)::a), mshow x)

-- Note that we cannot translate this program to Haskell,
-- cause Haskell doesn't have lexically scoped type annotations.