∀ {α : Type u_1} {β : Type u_2} [inst : GroupWithZero α] [inst_1 : Preorder α] [inst_2 : Preorder β]
  [inst_3 : MulAction α β] [inst_4 : PosSMulMono α β] [inst_5 : PosSMulReflectLE α β] {a : α} (ha : 0 < a) (b : β),
  (RelIso.symm (OrderIso.smulRight ha)) b = a⁻¹ • b