amended elements when responding to a rejection. Had they known, the Court stated, they might have appealed the rejection. With this policy in mind, the Court stated that it preferred a presumptive bar approach to the doctrine of equivalents. This presumptive bar approach holds that where claims are amended, "the inventor is deemed to concede that the patent does not extend as far as the original claim" and the patentee has the burden of showing that the amendment does not surrender the particular equivalent. To succeed, then, the patentee must establish that: the equivalent was unforeseeable at the time the claim was drafted; the amendment did not surrender the particular equivalent in question; or there was some reason why the patentee could not have recited the equivalent in the claim. See also Prosecution disclaimer References Patent law Estoppel