data Typ = TInt | TInteger | TUnk deriving Show
data ExprNum = ExprNum Typ Integer deriving Show

data TExprNum a = TExprNum a

{-
f (ExprNum TInt x) = TExprNum (fromInteger x) :: TExprNum Int
f (ExprNum TInteger x) = TExprNum (fromInteger x) :: TExprNum Integer
f _ = error "nope"
 -}
main = do
  let e1 = ExprNum TInt 25
  let e2 = ExprNum TInteger 6
  print $ e1
  print $ e2
  {-
  let t1 = f e1
  let t2 = f e2
  print $ t1
  print $ t2
  -}