A total order for `Maybe a` where `a` has a total order
and `Nothing` is the minimal value.
This is useful, for instance, when implementing provably
sorted (assoc-) snoc-lists, indexed by a `Maybe key`, where
the empty list has a `Nothing` index.
Totality: total
Visibility: public export
Constructors:
LNothing : Lower lt Nothing (Just v) LJust : lt v w -> Lower lt (Just v) (Just w)
Hints:
Transitive a lt => Transitive (Maybe a) (Lower lt) Trichotomous a lt => Trichotomous (Maybe a) (Lower lt) Uninhabited (Lower lt m Nothing) Strict a lt => Uninhabited (Lower lt (Just k) (Just k))