Hello Cafè, I'd like to share a piece of code I've found useful to nest ordering on EQ. {-# language GADTs #-} import Data.Monoid (mconcat) import Data.Ord (comparing) data Orderings t where Ascending :: Ord a => (t -> a) -> Orderings t Descending :: Ord a => (t -> a) -> Orderings t comparings :: [Orderings t] -> t -> t -> Ordering comparings c x y = mconcat $ map g c where g (Ascending f) = comparing f x y g (Descending f) = comparing f y x I couldn't find a simpler solution, maybe somebody else has one. I've tried using comparings :: [forall a. Ord a => t -> a] -> t -> t -> Ordering which is not compiling for impredicativity and I'd like to understand better. An example on sorting (Ord a, Ord b, Ord c) => [(a,(b,c)] with 'a' in opposite order, then 'c' and 'b' in ascending order goes like sortBy (comparings [Descending fst, Ascending $ snd . snd, Ascending $ fst . snd]) Thanks for help/comments paolino