# Commit 2022-07-11 09:33 40fdf72d

View on Github →feat(category_theory/endofunctor/algebra): Define coalgebras over an endofunctor and prove an equivalence (#14834)
This PR dualises the definition of an algebra over an endofunctor to that of a coalgebra over an endofunctor. Furthermore, it proves that if an endofunctor `F`

is left adjoint to an endofunctor `G`

, then the category of algebras over `F`

is equivalent to the category of coalgebras over `G`

.