∀ {𝕆 : Type u_2} {α : Type u_1} {β : Type u_3} [inst : Preorder 𝕆] [inst_1 : Preorder α] [inst_2 : Preorder β]
  [inst_3 : GradeOrder 𝕆 β] (f : α → β), StrictMono f → StrictMono (GradeOrder.grade ∘ f)