  A natural way to account for these diverging readings is to posit two respective readings of ‘book’: one on which it is used to pick out physical books (of which we have three), and one on which it is used to pick out “informational” books (of which we have one). However, on further reflection this still leaves a puzzle concerning (47): if ‘book’ in this sentence picks out an informational book (arguably a kind of abstract entity), how can this kind of object have the physical property of being on the shelf? These kind of apparently ‘mixed’ reading are referred to in the literature as instances of copredication.