488 F.2d 538, 541-42, 179 USPQ 421, 423-24 (CCPA 1973). Unlike the applicant in Jolly, Exxon has the benefit of a statutory presumption of validity, 35 U.S.C. § 282. In light of that presumption and the difference in posture between an applicant whose application has been rejected and a patentee with an issued patent, close questions of indefiniteness in litigation involving issued patents are properly resolved in favor of the patentee. Thus, in cases subsequent to In re Jolly that have involved issued patents, this court has held claims definite even when some degree of experimentation was necessary, as long as the claims otherwise met the enablement requirement. See, e.g., Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus., 145 F.3d 1303, 1312, 46 USPQ2d 1752, 1759 (Fed.Cir.1998) (<HOLDING>); W.L. Gore & Assocs., 721 F.2d at 1557, 220
holding that duration of limitation is a factor in determining whether limitation is significant holding that a whereby clause that was substantially amended to overcome prior art was sufficiently definite to constitute a claim limitation and did not simply announce the inventions result holding that the recitation of a quantitative drop rod test rendered definite a claim limitation recognizing that a principal may limit the authority of its agent and such limitation will be binding on a third party who is aware of the limitation holding that the patentees argument that any shape would be equivalent to the conical limitation would write such a limitation out of the claim