a) Amendment allowed 

In T 271/84 (OJ 1987, 405) it was stated that an amendment to a claim to clarify an inconsistency did not contravene Art. 123(2) or Art. 123(3) EPC 1973 if the amended claim had the same meaning as the unamended claim, on its true construction in the context of the specification.

In T 758/92 the board allowed the deletion of a feature because it was clearly inconsistent with the teaching disclosed in the application as filed, and there was a clear basis in the original disclosure for its deletion. A skilled reader of the original application documents would have realised that the feature to be deleted was erroneously introduced in the claim because the resulting definition was contradictory to the functioning of the described embodiment of the invention.

In T 609/95 the board took the position that where a drafting defect or inconsistency in an application would be evident to a reader skilled in the art, the person to whom the application is addressed, it is reasonable to suppose that he would, in the light of the content of the application, attempt to formulate a notional amendment which would enable him to make sense of what he reads, and to the extent that the amendment might be said to leap to the mind of the reader, although perhaps only after close study of the document, it can be regarded as implicit in the application and would not contravene Art. 123(2) EPC 1973, if effected in practice (see also T 887/97 for such amendment during opposition appeal proceedings).