 The neo-Fregean revival had its origin in an insight of Charles Parsons (see Parsons 1965: 183 and 194). He pointed out that what he called principle (A) below suffices, given the structure of Frege’s argumentation in the Grundlagen, for the derivation of the axioms of Peano arithmetic. Parsons uses the binary quantifier ‘Glz’ to abbreviate “gleichzahlig” (equinumerous), and uses Nx to abbreviate “the number of”: 