1Additional IP Rights Grant (Patents)
 2
 3"This implementation" means the copyrightable works distributed by
 4Google as part of the Go project.
 5
 6Google hereby grants to You a perpetual, worldwide, non-exclusive,
 7no-charge, royalty-free, irrevocable (except as stated in this section)
 8patent license to make, have made, use, offer to sell, sell, import,
 9transfer and otherwise run, modify and propagate the contents of this
10implementation of Go, where such license applies only to those patent
11claims, both currently owned or controlled by Google and acquired in
12the future, licensable by Google that are necessarily infringed by this
13implementation of Go.  This grant does not include claims that would be
14infringed only as a consequence of further modification of this
15implementation.  If you or your agent or exclusive licensee institute or
16order or agree to the institution of patent litigation against any
17entity (including a cross-claim or counterclaim in a lawsuit) alleging
18that this implementation of Go or any code incorporated within this
19implementation of Go constitutes direct or contributory patent
20infringement, or inducement of patent infringement, then any patent
21rights granted to you under this License for this implementation of Go
22shall terminate as of the date such litigation is filed.