{α : Sort u_1} →
  {β : Sort u_2} →
    {P : Sort u} →
      {toFun : α → β} →
        {inj' : Function.Injective toFun} →
          {toFun' : α → β} →
            {inj'' : Function.Injective toFun'} →
              { toFun := toFun, inj' := inj' } = { toFun := toFun', inj' := inj'' } → (toFun ≍ toFun' → P) → P