 Given that there is only one incumbent pope and that it can’t have taken Carnap any effort to be born on May 18, 1891, both (49a) and (49b) suffer from presupposition failure. But if someone who knew that there was only one incumbent pope uttered (49a), it would not seem entirely natural to say that they had lied. One might even say that these sentences are true, and this intuition does not seem to be topic dependent. The reason for this may be that the presuppositions in question are incidental to the primary content of these sentences.