∀ {α : Type u} [inst : SizeOf α] (uniformity : Filter (α × α)) (refl : Filter.principal SetRel.id ≤ uniformity)
  (symm : Filter.Tendsto Prod.swap uniformity uniformity)
  (comp : (uniformity.lift' fun s => SetRel.comp s s) ≤ uniformity),
  sizeOf { uniformity := uniformity, refl := refl, symm := symm, comp := comp } = 1 + sizeOf uniformity