An objective definition of the problem to be solved by the invention should normally start from the problem described in the contested patent. Only if examination shows that the problem disclosed was not solved or if inappropriate prior art was used to define the problem, is it necessary to investigate which other problem objectively exists (T 1060/11: "established case law"). The definition of artificial and technically unrealistic problems is to be avoided (see T 495/91, T 741/91, T 334/92, T 813/93, T 68/95, T 644/97, T 747/97, T 946/00). This legal principle is also applicable to ex parte proceedings (T 881/92, T 882/92, T 884/92). In T 419/93 it was added that, when determining the problem, the statements relating thereto in the application should be examined for correctness with regard to the prior art and for their de facto relevance to the claimed features of the solution. Only if the problem described in the application did not meet prior art requirements and/or was not solved in accordance with the features of the invention, should it be adapted to the prior art and/or actual technical success. In this connection, T 800/91 emphasised that in any event the formulated problem should be one which the skilled person knowing only the prior art would wish to solve. It should not be tendentiously formulated in a way that unfairly directed development towards the claimed solution. In T 400/98, the technical problem set out in the patent had to be reformulated because it had not been credibly solved.

In T 1263/11 the board observed that there was no disclosure of the terms "microscopic surface properties" and "macroscopic surface properties" in the patent in suit. It was not shown that those terms had well-defined, unambiguous definitions in the art. Consequently, they could not be used to formulate the problem to be solved.

In T 2341/13 the invention related to the hardware implementation of an interleaver. The examining division had considered it problematic that the application suggested that the invention could be used in a communication system based on a standard that was neither publicly available at the priority date nor fully disclosed in the application. The board observed that knowledge of any communication standard was not necessary to carry out the claimed invention and that it was perfectly valid to pose the problem of obtaining interleavers for frame sizes that were not a multiple of 2**(m). If the claimed solution to this problem was not rendered obvious by the prior art, then an inventive step was present. Whether the application sufficiently disclosed the advantages of such frame sizes was irrelevant, unless it was argued that the mere idea of using such frame sizes was itself inventive (in which case it could not be included in the problem formulation).