importing (<=) from GHC.TypeLits

[Henning Thielemann]

I want to import Nat and type-level (<=) from GHC.TypeLits:

   import GHC.TypeLits (Nat, (<=))

"Nat" is found this way, but (<=) is not:

   Module ‘GHC.TypeLits’ does not export ‘(<=)’

What is the trick?

The doc only shows the anonymous import:

http://www.haskell.org/ghc/docs/7.8.1-rc2/html/users_guide/promotion.html