# Commit 2020-06-08 17:34 9fba817f

View on Github →refactor(algebra/*): move `commute`

below `ring`

in `import`

s (#2973)
Fixes #1865
API changes:

- drop lemmas about unbundled
`center`

; - add
`to_additive`

to`semiconj_by`

and`commute`

; - drop
`inv_comm_of_comm`

in favor of`commute.left_inv`

, same with`inv_comm_of_comm`

and`commute.left_inv'`

; - rename
`monoid_hom.map_commute`

to`commute.map`

, same with`semiconj_by`

; - drop
`commute.cast_*_*`

and`nat/int/rat.mul_cast_comm`

, add`nat/int/rat.cast_commute`

and`nat.int.rat.commute_cast`

; - add
`commute.mul_fpow`

.