- * Once we reach u_10 for the second time, we start with u_10 < 2^11. The
- * carry into u_10 is at most 2557*2^10 < 1279*2^11 as calculated above; so
- * the carry out into u_11 is at most 1280. Since u_11 < 2^10 prior to
- * this carry in, all of the u_i are now bounded above by 2^11. The final
- * reduction therefore only needs a conditional subtraction.
+ * Once we reach u_9 for the second time, we start with u_9 < 2^11. The
+ * carry into u_9 is at most 2557*2^10 < 1279*2^11 as calculated above; so
+ * the carry out into u_10 is at most 1280. Since u_10 < 2^11 prior to
+ * this carry in, we now have u_10 < 2^11 + 1280 < 2^12; so the carry out
+ * into u_11 is at most 1. The final reduction therefore only needs a
+ * conditional subtraction.