In Arendi S.A.R.L. v. Google LLC, the Federal Circuit upheld a PTAB finding that Arendi’s claims at issue in an IPR were obvious, despite a narrow construction resulting from prosecution disclaimer.  Prosecution disclaimer traditionally arises when a patent applicant “clearly and unambiguously” surrenders claim scope during prosecution, usually by arguments and related claims amendments.  During prosecution, Arendi argued that “in the Tso reference, the user must select the text string to be processed, whereas, in the present invention, the user does not have to select the text string to be analyzed.” Arendi then made a related amendment to its claims.  In the IPR brought by Google, the PTAB invalidated all of Arendi’s claims as obvious, whether or not prosecution disclaimer applied.  On appeal, Arendi argued for a narrow claim scope based on its own prosecution disclaimer in an attempt to avoid prior art.  The Federal Circuit agreed with Arendi and found a prosecution disclaimer, but it nevertheless affirmed the PTAB finding of obviousness even with the narrower, disclaimed claim construction.