Care must also be taken to ensure that any amendment to, or subsequent insertion of, a statement of the technical problem solved by the invention meets Art. 123(2). For example it may happen that following restriction of the claims to meet an objection of lack of inventive step, it is desired to revise the stated problem to emphasise an effect attainable by the thus restricted invention but not by the prior art. It must be remembered that such revision is only permissible if the effect emphasised is one deducible by a person skilled in the art without difficulty from the application as filed (see 5.3.3 and 5.3.4 above).