TypeFun.Data.Peano
data N
type family ToNat (a :: N) :: Nat where ...
type family FromNat (a :: Nat) :: N where ...
type family (a :: N) :+: (b :: N) :: N where ...
type family (a :: N) :-: (b :: N) :: N where ...
type family (a :: N) :*: (b :: N) :: N where ...