∀ {X : Type u_5} [inst : TopologicalSpace X] [inst_1 : SizeOf X] (toSetoid : Setoid X)
  (isOpen_setOf_rel : ∀ (x : X), IsOpen (setOf (toSetoid x))),
  sizeOf { toSetoid := toSetoid, isOpen_setOf_rel := isOpen_setOf_rel } = 1 + sizeOf toSetoid