# Commit 2020-04-18 12:23 ffb99a33

View on Github →chore(algebra/group/type_tags): add `additive.to_mul`

etc (#2363)
Don't make `additive`

and `multiplicative`

irreducible (yet?) because
it breaks compilation here and there.
Also prove that homomorphisms from `ℕ`

, `ℤ`

and their `multiplicative`

versions are defined by the image of `1`

.