“…Hence, if [C]J is multiplicitly-free, thenm(C, λ) =m(C, λ) 2 for all λ ∈ Λ and so C (2) = C∩C −1 . On the other hand, if C (2) = C∩C −1 , then λ∈Λm (C, λ) = λ∈Λm (C, λ) 2 and som(C, λ) ∈ {0, 1} for all λ ∈ Λ. Thus, up to signs, the numbers c w,λ are the leading coefficients of character values as defined by Lusztig [14].…”