Commit 2020-05-31 04:59 a285049b
View on Github →chore(algebra/group_hom): rename add_monoid.smul to nsmul (#2861)
Also drop • as a notation for two smuls  declared in this file,
use •ℕ and •ℤ instead.
This way one can immediately see that a lemma uses nsmul/gsmul, not has_scalar.smul.