T 0271/84 (Gas purification) vom 18.03.1986

1. If a process has been performed successfully on a commercial scale for more than 20 years in spite of economic disadvantages associated with it, and the claimed invention provides a solution to the technical problem of avoiding such economic disadvantages, this supports a finding of inventive step.

2. An amendment to a claim to clarify an inconsistency does not contravene Art. 123(2) or (3) if the amended claim has the same meaning as the unamended claim, on its true construction in the context of the specification.

3. The introduction of new grounds of opposition and new documents at the appeal stage of opposition proceedings may not be allowable, in the exercise of discretion under Art. 114(2), depending especially upon the degree of relevance and the lateness.