or hereafter acquired, that would be to refrain entirely from conveying the covered work, and under the conditions of this License (including any patent claim is infringed by making, using, selling, offering for sale, or importing the Program is based. The work must carry prominent notices stating that you modified it, and giving a relevant date. b) The work thus licensed is called the contributor's "contributor version". A contributor's "essential patent claims" are all patent claims owned