monoids-in-the-category-of-.../src/Category/Groupoid.hs

9 lines
233 B
Haskell

module Category.Groupoid (Groupoid, inv) where
import Category.Base
import Data.Kind (Constraint, Type)
type Groupoid :: (i -> i -> Type) -> Constraint
class Category morph => Groupoid morph where
inv :: morph a b -> morph b a