a) Principles 

As stated in CA/3/19 (section V.B.a), point 49), one of the most important elements of the "convergent approach" is that the onus is on a party to explain and justify any amendment to its case. That includes providing reasons for not submitting the amendment at an earlier stage in the appeal proceedings (Art. 13(1), third sentence, RPBA 2020; see chapter V.A.4.4.4b) below). In the case of an amendment to a patent application or patent, the party must indicate the basis for it in the application as filed (Art. 13(1), second sentence, RPBA 2020 in conjunction with Art. 12(4), fourth sentence, RPBA 2020) und demonstrate that, prima facie, it overcomes the issues raised by either another party in the appeal proceedings or by the board and does not give rise to new objections (Art. 13(1), fourth sentence, RPBA 2020).