mathlib3

7f358d06 - feat(category_theory/preadditive/eilenberg_moore): (Co)algebras over a (co)monad are preadditive (#14811)

feat(category_theory/preadditive/eilenberg_moore): (Co)algebras over a (co)monad are preadditive (#14811) The category of algebras over an additive monad on a preadditive category is preadditive (and the dual result). Co-authored-by: Julian-Kuelshammer <68201724+Julian-Kuelshammer@users.noreply.github.com> Co-authored-by: Markus Himmel <markus@himmel-villmar.de>