Russell's Principia Mathematica (PM) is indeed better engineered than its predecessor by Frege because it has orders on propositions. Because of orders on pro

Russell's Principia Mathematica (PM) is indeed better engineered than its predecessor by Frege because it has orders on propositions. Because of orders on proportions, PM does not allow the [Gödel 1931] proposition I'mUnprovable. Furthermore, adding the proposition I'mUnprovable would make PM inconsistent. The Gödel number of a proposition in PM is itself "incomplete" because it *doesn't* include the order of the proposition. Allowing its Gödel number to represent a proposition is indeed a kind of "code injection" attack, which if allowed would make PM inconsistent.