b) Novelty 

For the purpose of assessing novelty, the party alleging that the inevitable outcome of a prior art disclosure is in contradiction with the explicit disclosure of the cited prior art has not only the burden of reproducing the earlier disclosure in such a way as to demonstrate that the alleged inevitable outcome has occurred, but also the burden of proving convincingly that if any significant deviation from the conditions specified in the earlier disclosure are not material to the outcome (T 204/00; see also T 396/89).

In T 713/01 the appellant denied the existence of an "enabling" disclosure in D2 with regard to the preparation of polymers in the presence of a solubilised lithium pyrrolidide initiator by reference to T 124/87 (OJ 1989, 491) and T 206/83 (OJ 1987, 5). The board held that the only difference between D2 and the claim wording did not qualify as a distinguishing feature of the claimed product because that "product-by-process" feature was not detectable on the product by a reliably distinguishing property. In this context, the board added that in proceedings before the examining division the burden of proof for an allegedly distinguishing "product-by-process" feature lay with the applicant (see further T 205/83, OJ 1985, 363 and T 279/84). Decision T 713/01 was clearly concerned with the question of burden of proof in examination proceedings (T 1912/10).

In T 664/20, point 2 of the Catchword, the board stated that when a patent proprietor amends a product claim to specify that the product is intended for a particular use, the patent proprietor has to prove that the prior art products that have been cited to show a lack of novelty and which satisfy all the other features of the claim are unsuitable for the use in question.

In T 172/20 it was decided that the burden of proof remained with the opponent since the parameter in dispute was not an unusual parameter; it was for the opponent to prove beyond reasonable doubt that the claimed subject-matter had been directly and unambiguously disclosed in the prior art.

In T 2916/19 the nature of the catalyst system and the mode of preparation thereof were crucial, and in relation to the objections based on enabling disclosure (E1), considering that E1 constituted a written disclosure and not an alleged public prior use, the circumstances were not the same as in G 1/92 and T 1833/14, which were both relied upon by the respondent (proprietor). Nevertheless, the arguments were equally relevant for the written disclosure E1. Indeed, in view of the respondent's submissions, the question arose as to whether or not the skilled person would be able to prepare without undue burden any of samples 1, 3 and 5 of E1 in view of the very limited information provided in E1 regarding their preparation process, in particular regarding the catalyst system used, even taking into account common general knowledge. It was in dispute between the parties whether the burden of proof regarding enablement of samples of E1 was on the appellant/opponent or on the respondent/patent proprietor. Since the appellant/ opponent raised objections (lack of novelty and inventive step) based on the disclosure of samples of E1, the burden of proof primarily resided with them to show that said samples of E1 effectively belonged to the state of the art. Also, according to established case law, the requirements of sufficiency of disclosure were identical for a prior art document and a patent (T 1437/07). Since there were serious doubts substantiated by verifiable facts supporting the objection of lack of enablement raised by the respondent (proprietor) against samples of E1, the burden of proof was on the appellant. The appellant also unconvincingly argued, with reference to the minutes, that the objection that E1 was not enabling should be rejected since the respondent argued the contrary in the opposition proceedings.

See chapter I.C. "Novelty".