In T 134/94 the priority document disclosed a process which worked under specific conditions indicated as features (a) to (d). Requirements (a) and (c) did not appear in the granted claim of the patent in suit. The board held that this claim was not entitled to priority. As requirements (a) and (c) did not appear in the granted claim the scope of the invention as defined thereby comprised areas which, according to the priority document, did not belong to the invention. Thus the invention defined by granted claim 1 was not the same as that defined in the priority document. On the priority date the technical problem underlying the invention was considered to be solved only if each of the conditions (a) to (d) was satisfied; according to granted claim 1 features (a) and (c) were no longer necessary for solving the problem underlying the invention. According to the board, the respondent's position that the priority claim should be acknowledged whenever the disclosure of the priority document would destroy the novelty of the claims of the later application or patent ("novelty test") had no basis either in the EPC or in the EPO case law. Such a position would imply that essential features of an invention disclosed in a priority document could be omitted in a later application based thereon without loss of priority right. However, if an essential feature of an invention was so omitted, the invention was no longer the same, i.e. the requirement of Art. 87(1) EPC 1973 was not fulfilled.
In T 552/94 the patent's claim 1 lacked four features which according to the priority document were indispensable for carrying out the invention. In other words, they were no longer essential to the invention as now defined. Citing T 134/94 and T 1082/93, the board found that without those features the invention according to claim 1 could not be the same as that described in the priority document, and the requirements of Art. 87(1) EPC 1973 were therefore not met.
In T 1050/92, on the other hand, the disclosure of the invention in the earlier application provided an adequate basis for replacing the term used in said application with a more general one in the European application.