∀ {α : Type u_2} {β : Type u_3} [inst : AddCommMonoid α] [inst_1 : PartialOrder α] [inst_2 : AddCommMonoid β]
  [inst_3 : PartialOrder β] [inst_4 : SMulZeroClass α β] [inst_5 : FloorDiv α β] {a : α}, a ≤ 0 → ∀ (b : β), b ⌊/⌋ a = 0