W 0006/90 (Single general concept) of 19.12.1990

1. A single general concept within the meaning of Rule 13.1 PCT manifests itself in features common to different teachings expounded individually in the same application. It must, however, be borne in mind that such a teaching encompasses not only the immediate subject-matter representing the solution to the problem as defined in the relevant claim but also its technical consequences which are expressed as effects (see point 3.2 paragraph 2 of the Reasons for the Decision).

2. A single general concept may therefore be said to be present only if a partial identity exists among the teachings in an application deriving from the structural features of the subject- matters claimed and/or the outcome or results associated with those subject-matters (see point 3.2 paragraph 3 of the Reasons for the Decision).

3. For the purposes of unity of invention, Rule 13.1 PCT also stipulates that the single general concept must be inventive. Even with a given single general concept there is lack of unity if the concept has no inventive character. Before issuing an invitation to pay an additional search fee on the basis of lack of unity, the search examiner must accordingly demonstrate that, given the general knowledge of the person skilled in the art ("a priori") or the state of the art - as revealed by the search - relating to the subject-matter first defined in the claims ("a posteriori"), the substance of the single general concept can evidently contribute nothing to the inventive step (see point 3.3 paragraphs 1 and 3 of the Reasons for the Decision).