definiens: means any challenge in a legal or administrative proceeding to the patentability, validity or enforceability of any of thePatent Rights ( or any claim thereof ), including by : ( a ) filing or pursuing a declaratory judgment action in which any ofthe Patent Rights is alleged to be invalid or unenforceable ; ( b ) citing prior art against any of the Patent Rights, filing arequest for or pursuing a re - examination of any of the Patent Rights ( other than with COH ’s written agreement ), orbecoming a party to or pursuing an interference ; or ( c ) filing or pursuing any re - examination, opposition, cancellation, nullity or other like proceedings against any of the Patent Rights ; but excluding any challenge raised as a defenseagainst a claim, action or proceeding asserted by COH against Licensee, its Affiliates or Sublicensees . In lieu ofexercising its rights to terminate under this Section 7.3 COH may elect upon written notice to increase the paymentsdue under all of Article 4 by * percent ( * % ), which election will be effective retroactively to the date of thecommencement of the Patent Challenge . Licensee acknowledges and agrees that this Section 7.3 is reasonable, validand necessary for the adequate protection of COH ’s interest in and to the Patent Rights, and that would not havegranted to Licensee the licenses under those Patent Rights, without this Section 7.3