∀ {α : Type u} {β : α → Type v} [inst : Ord α] [Std.TransOrd α] [inst_2 : BEq α] [Std.LawfulBEqOrd α]
  {l : Std.DTreeMap.Internal.Impl α β},
  l.Ordered → ∀ {fallback : α}, l.minKeyD fallback = Std.Internal.List.minKeyD l.toListModel fallback