Commit 2026-09-01 10:16 ea7d8e76
View on Github →chore(Algebra/Order/Ring/WithTop): use to_dual (#42628)
This PR uses to_dual on Ring-related declarations on WithTop/WithBot. Some lemmas and instances only existed for WithTop, so they have now been added for WithBot.
The type class assumption for the ring instances have been weakened into a form that to_dual is happy with. It now only assumes [Subsingleton (AddUnits α)] instead of [PartialOrder α] [CanonicallyOrderedAdd α].
Some generic instances about CovariantClass were given a low priority because to_dual doesn't like them.