“…The proof in the book is flawed and rests on the incorrect inference from 'No B is A' to 'No B is necessarily A'. 34 To see that XLX Baroco is invalid, consider the following counter-model: w 1 , B). However, M, w CaA since b / ∈ V (w, C) while a ∈ V (w, C) and a ∈ V (w, A).…”