{α : Type u_1} →
  {β : Type u_2} →
    [inst : Std.PRange.UpwardEnumerable α] →
      [inst_1 : Std.PRange.UpwardEnumerable β] →
        [inst_2 : Std.Rxi.HasSize α] →
          [inst_3 : Std.Rxi.HasSize β] →
            {f : Std.PRange.UpwardEnumerable.Map α β} →
              {motive : f.PreservesRxiSize → Sort u} →
                (t : f.PreservesRxiSize) →
                  ((size_eq : ∀ {b : α}, Std.Rxi.HasSize.size b = Std.Rxi.HasSize.size (f.toFun b)) → motive ⋯) →
                    motive t