Commit 2024-12-13 13:44 ddbd4951
View on Github →refactor(Algebra/Category/Ring): make morphisms a structure (#19757)
Following the pattern of #19065, we introduce a Hom
structure for morphisms in SemiRingCat
, CommSemiRingCat
, RingCat
and CommRingCat
allowing for many simp
lified proofs and reducing the need of erw
.
Besides the additional explicitness in form of ofHom
and Hom.hom
, the main regression is friction with the FunLike
instance from the general ConcreteCategory
API, causing the need for explicit rw
s between f.hom x
and (forget RingCat).map f x
. This regression can be fixed by replacing the general ConcreteCategory.instFunLike
by a CoeFun
(or FunLike
) instance that is part of the ConcreteCategory
data.