1) I would prefer that you say yourself that your magic triangle is not the one of M theory but rather extends the one of Tits, so that people do not get the false impression that you did it right and first. You did it right for some invariant theory problem that is special and connects to other things than my triangle and you know CJ did not know your preprint E7 came as 70+63=133 for us! 2) I propose that you use the terminology contragredient to not commit yourself too soon to unitary representations the complex conjugations are to be avoided for instance avoid conjugate multiplet with your definition it should come with complex conjugation p2 p3 dual space should be DEFINED without cc it turns out equal p4 the Kronecker is always an invariant the quadratic form or hermitian form is what defines SO or SU or SH=USP groups IF YOU STICK TO YOUR NOTATION YOU STICK TO SUBGROUPS OF O(N) for no reason bottom of p6 there are r+1 invariants in your list also the definition of combination is not clear in def at top of 2.5 More later form an average physicist! Bernard L. JULIA ENS-CNRS/LPT 24 rue Lhomond 75005 Paris FRANCE Tel. (01)47077146. FAX. (01)43367666.