∀ {α : Type u_5} {β : Type u_6} {r : α → α → Prop} {s : β → β → Prop} {toFun : α → β}
  {map_rel' : ∀ {a b : α}, r a b → s (toFun a) (toFun b)} {toFun_1 : α → β}
  {map_rel'_1 : ∀ {a b : α}, r a b → s (toFun_1 a) (toFun_1 b)},
  { toFun := toFun, map_rel' := map_rel' } = { toFun := toFun_1, map_rel' := map_rel'_1 } → toFun = toFun_1