prop_Tnorm :: (Show a, Arbitrary a, Tnorm a) => T a -> PropBox
prop_Tnorm = prop_tnorm . tie
  where tie :: Tnorm a => T a -> (a -> a -> a)
        tie _ = tnorm
prop_Tnorm :: (Show a, Arbitrary a, Tnorm a) => T a -> PropBox
prop_Tnorm = prop_tnorm . tie
  where tie :: Tnorm a => T a -> (a -> a -> a)
        tie _ = tnorm
prop_Tnorm = prop_tnorm . tie
  where tie :: Tnorm a => T a -> (a -> a -> a)
        tie _ = tnorm