Where subject-matters of the same category were concerned, a partial identity, generating unity of invention, could result from the structural features of these subject-matters and/or their associated effects. The absence of such an element common to all the different teachings in the application, and hence a lack of unity, might be established a priori under certain circumstances. A lack of unity might, however, also be established a posteriori between the subject‑matters of different independent claims or in the remaining subject‑matters if the subject‑matter of a linking claim was clearly not novel or inventive vis‑à‑vis the state of the art. The board gave an example of what was meant by the abstract term "single general concept": a product, a process specially adapted for the manufacture of the said product, and a use of the said product, for example, embodied a single general concept because, on the one hand, the partial identity between the product and its use derived from the structural features of the product and, on the other hand, the partial identity shared by the product and the process specially adapted for its manufacture also derived from the product which was to be considered as the effect or result of this process (see T 119/82
, OJ 1984, 217).