The preamble admits the existence of prior art, on which the actual invention in the claims body is based in the form of an improvement of the prior art. For patent examiners this represents an easy way of identifying those elements of the claim that are new and inventive. Box 1, and case T128/82, OJ EPO 1984, p. 164, as cited by South Centre Guide, p. 140, see also R. J. Young, “The construction of product-by-process claims”, in The construction of product-by-process claims, 11th European Patent Judges’ Symposium, Copenhagen, Official Journal of the EPO 2003, Special Edition, No.