“…In [7,9], in studying the case of G 2 , a more general strategy (later reviewed in [8]), which was expected to be applicable case by case to all compact simply connected simple Lie groups, has been developed. Indeed, it has been first applied to the SU (N ) case in [10], showing the drastic simplification with respect to [26,27], and successively to the exceptional Lie groups F 4 , E 6 and E 7 in [6,5,4] respectively. It is only after these several years experience that we realized that the success of our method was due to the deep geometrical structure of the compact connected simple Lie groups, and, in fact, of all compact connected Lie groups.…”