Commit 2021-04-27 07:21 20c520a6
View on Github →feat(algebra/opposite): inversion is a mul_equiv to the opposite group (#7330)
This also splits out monoid_hom.to_opposite
from ring_hom.to_opposite
, and adds add_equiv.neg
and mul_equiv.inv
for the case when the (add_)group
is commutative.