**T1409 / 16: interpretation of “either … either” and extrinsic characteristic**

The decision is interesting in two respects.

The claimed lye contained a substituted cellulose having a degree of substitution DS and a degree of DB block presence with either ( *either* ) DS + DB> 1 or ( *gold* ) DB + 2DS-DS²> 1.20.

The Opponent argued that the two conditions were exclusive because of the use of “either … or”. If the Holder had wanted an inclusive “or” she would have used the expression “and / or”, which she did in claim 9.

The House does not agree. It notes that the term “either … or” may be an exclusive or inclusive disjunction, so that the claim is unclear and needs to be interpreted taking into account the entire patent. In this case, some examples indicated as being according to the invention have both properties. In addition, the mathematical analysis of the two inequalities reveals that they are not mutually exclusive. It is only for a small couple of (DS, DB) that only one of the two inequalities is respected.

With respect to novelty, the Opponent cited documents describing detergents containing carboxymethylcellulose ” *Finnfix BDA* “. Now, by splitting this cellulose, the Opponent has obtained a fraction F1 respecting both inequalities. Since the claim is open, all compositions of the prior art contained this F1 fraction and were therefore in accordance with the claim.

The House is not convinced either. Polymeric components contain molecules differing in chain length. The fact of intellectually separating these components into several fractions and attributing to one of these fractions (also composed of molecules of different chain lengths) a physical property distinguishing this fraction from the others is an artificial and *a posteriori approach.*

The DB and DS values obtained by analyzing the product as a whole do not respect the inequalities. These are the values that are made available to the public through product analysis.

This conclusion is consistent with G1 / 92 that a commercial product does not disclose ” *extrinsic characteristics , which only occur when there is interaction between the product and specifically selected external conditions , such as reagents or products of the same kind, in order to obtain a particular effect or result or to discover results or potential means, go beyond the product itself, insofar as they depend on deliberate choices.* “

The splitting performed is a kind of reverse engineering revealing such an extrinsic feature.