 Readers interested in learning more about Frege’s notation can consult Beaney (1997, Appendix 2), Furth (1967), Reck &amp; Awodey (2004, 26–34), and Cook (2013). In what follows, however, we shall continue to use the notation of the modern predicate calculus instead of Frege’s notation. In particular, we adopt the following conventions: