To establish whether the invention claimed in the subsequent European application was already disclosed in the earlier previous application, the same principles have to be applied as when establishing identity of invention between the application forming the basis of priority and the application claiming priority. The question is whether the person skilled in the art could derive the subject-matter of the claim of the subsequent application directly and unambiguously, using common general knowledge, from the earlier previous application or only from the later one (cf. G 2/98, OJ 2001, 413).

In T 323/90 the board concluded that the alleged first application disclosed a different invention from that in the European application and the application from which priority had been claimed: the claimed process (for increasing the filling power of tobacco lamina filler) differed as regards both the moisture content of the tobacco for processing and the first step in the process.

In T 400/90 priority had been claimed from a US application in respect of a European application concerning an electromagnetic flowmeter. According to the opponents, an earlier US application filed by the same applicant outside the priority period disclosed all the features contained in the European application with the exception of the use of saddle-shaped coils; however, the latter were already known and used frequently. In the board's opinion, the question to be answered was whether the use of saddle-shaped coils had been disclosed in the earlier US application, and not whether it was obvious to use such coils in place of the magnets disclosed in the earlier application. The board concluded that the inventions claimed in the US applications were different and priority had rightly been claimed from the later application because, according to the teaching of the earlier application, coils of any shape could be used, whereas according to the teaching of the priority document saddle-shaped coils had to be used.

In T 184/84 the Japanese application from which priority was claimed in the European patent application but also an earlier Japanese application claimed a method of producing a single crystal of ferrite. The starting materials were defined differently in the two Japanese applications. The method disclosed in the later application and the European application was clearly more advantageous than that forming the subject-matter of the earlier one. The board held that the significant differences in properties were indicative of the presence of different materials and therefore found that the earlier Japanese application was not the first filing of the invention claimed in the European patent application. It based its finding on T 205/83 (OJ 1985, 363), which stated that the novelty of products prepared using a modified process could be established by the fact that according to an empirical principle in chemistry, a product's properties were determined by its structure, so that differences in the properties of products indicated a structural modification.

The subject-matter of the patent in case T 107/96 contained the feature "angle of contact greater than 120°", which feature was disclosed in P2, the later of two previous US applications. In P2 a particular advantageous effect was also attributed to the large extent of the said "angle of contact". The earlier previous US application P1 was totally silent about the aforementioned feature "angle of contact" and its advantageous effect. However, the figures of P1 represented diagrammatic and schematic drawings. The board concluded that therefore, and in line with the established jurisprudence of the boards of appeal, they could not serve as a basis for determining the extent of a minimum "angle of contact" because dimensions obtained merely by measuring a diagrammatic representation of a document did not form part of the disclosure. Hence, the said feature "angle of contact greater than 120 ", was not disclosed in P1 but only in P2.

In T 449/04 the board referred to the Enlarged Board's narrow or strict interpretation in G 2/98 (OJ 2001, 413) of the concept of the "same invention" in Art. 87(1) EPC 1973 and concluded that the invention disclosed in the applicant's earlier application D1 was not the "same invention" as that disclosed in the priority application PR. With regard to a comparative example in D1, the composition of which fell within the elemental ranges claimed in the application-in-suit as well as in application PR, the board emphasised that the "same invention" considered in Art. 87(1) EPC 1973 did not encompass the comparative example(s), which were clearly and definitely excluded from the scope of the invention in D1. Having regard to the strict and narrow interpretation of the term "the same invention", this term was focused on what constituted the elements of the invention.

In T 1222/11 claim 1 had been amended to include six disclaimers for the purpose of restoring novelty over D4b, an earlier international (Euro-PCT) application of the same applicant, which had been published within the priority interval. The board found that the combination of features defined in positive terms in claim 1 (i.e. without any disclaimer) could not be distinguished from the disclosure of D4b and was not entitled to the claimed priority as far as it concerned the subject-matter already disclosed in D4b (Art. 87(1), (4) EPC). The compositions of D4b were therefore prior art under Art. 54(2) EPC. As the anticipatory disclosure of D4b was not an accidental anticipation (cf. G 1/03, OJ 2004, 413), the disclaimers based on it were not allowable under Art. 123(2) EPC. For further mention of this decision see chapter II.D.5.3.1.

In T 282/12 the board held that, for reasons of consistency, the rationale of decision G 1/15 (OJ 2017, A82 – concept of partial priority) must also apply in the context of deciding whether an application from which priority is claimed is the first application within the meaning of Art. 87(1) EPC. Indeed, just as a priority application and a patent claiming priority therefrom may partially relate to the same invention, the priority application and an earlier application filed by the same applicant may also do so. In that case, the priority application would be the first application in respect of only that part of the invention which is not the same as in the earlier application. Here, the board found that the earlier application filed by the applicant disclosed a range which was encompassed within the range of the priority document. Therefore, for that sub-range the priority document was not the first application. See also the summary of this decision in chapter II.D.5.3.3.