nLab
coalgebra over a comonad

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Idea

A coalgebra or comodule over a comonad CC on a category AA is an object aAa\in A with a morphisms aCaa\to C a satisfying axioms formally dual to those for an algebra over a monad. The category of coalgebras is called its (co-)Eilenberg-Moore category and satisfies a universal property dual to that of the Eilenberg-Moore object for a monad; it can thereby be internalized to any 2-category. The forgetful functor from the category of coalgebras to the category AA is called a comonadic functor. Similarly, a comonad also has a co-Kleisli category.

Created on March 31, 2016 at 05:06:37. See the history of this page for a list of all contributions to it.