  Kaplan maintains that ‘I am here now’ is logically valid, and yet he admits that the sentence ‘I am not here now’ is commonly used for answering-machine messages (1989a, 491, n. 12). For discussion of this “answering-machine puzzle,” see Predelli 1998a, 1998b; Corazza et al. 2002; Romdenh-Romluc 2002; and Cohen 2013.