“…In this work we study the quasi-minuscule quotients that are not minuscule. These quotients (also known as (co)-adjoint quotients) have been classified (see, e.g., [6]) and there are three infinite families and four exceptional ones. Using the standard notation for the classification of the finite Coxeter systems, the non-trivial (co)-adjoint quotients are: (A n , S \ {s 1 , s n }), (B n , S \ {s n−2 }), (D n , S\{s n−2 }), (E 6 , S\{s 0 }), (E 7 , S\{s 1 }), (E 8 , S\{s 7 }), and (F 4 , S\{s 4 }), where we number the generators as in [1] (see Appendix A1 and Exercises 20,21,22,23 in Chapter 8, and also below).…”