I think both these routing rules are sufficient to say that you can't buy an extra segment that would contravene these rules. I don't know that the fact that the European routing rules explicitly say you can't purchase a 3rd restricted segment change the fact that these rules say you can only fly one non-stop transcontinental flight or only fly a sector once in the same direction.


(l) Within the USA/Canada only one nonstop or single plane service transcontinental flight permitted.


i) The same city pairs/sectors cannot be flown more than once in the same direction