According to the established case law, the technical problem addressed by an invention has to be formulated in such a way that it does not contain pointers to the solution or partially anticipate the solution, since including part of a solution offered by an invention in the statement of the problem necessarily results in an ex post facto view being taken of inventive step when the state of the art was assessed in terms of that problem (see e.g. T 229/85, OJ 1987, 237; T 99/85, OJ 1987, 413; T 289/91, OJ 1994, 649; T 422/93, OJ 1997, 24; T 986/96; T 799/02; T 2049/11; T 2461/11).

In T 1019/99 the board stated that the correct procedure for formulating the problem is to choose a problem based on the technical effect of exactly those features distinguishing the claim from the prior art that is as specific as possible without containing elements or pointers to the solution (see also T 1557/07, T 1192/09).

In T 910/90 the board stated that, when assessing the objective problem, the closest prior art and any technical advance achieved by the characterising features of the invention had to be taken into account. In so doing, it was not important whether this problem had already been mentioned in the closest prior art; what mattered was what the skilled person objectively recognised as the problem when comparing the closest prior art with the invention (see also T 214/01).