Commit 2021-10-09 04:58 7a7fadaf

refactor(data/nat/basic): finish removing sub lemmas (#9601)

• Follow-up of #9544 to remove the remaining sub lemmas on nat that can be generalized to has_ordered_sub.
• The renamings of the lemmas in mathlib that occurred at least once:

nat.sub_eq_of_eq_add -> sub_eq_of_eq_add_rev
nat.add_sub_sub_cancel -> add_sub_sub_cancel'
nat.sub_le_self -> sub_le_self'