 [See Boolos 1987 (5), 1986 (140).] This principle asserts that for any concept \(F\), there is a unique object which contains in it all and only those concepts \(G\) which are equinumerous to \(F\). Boolos then makes two observations: (1) Frege can then define \(\#F\) as “the unique object \(x\) such that for all concepts \(G\), \(G\) is in \(x\) iff \(G\) is equinumerous to \(F\)”, and (2) Hume’s Principle is derivable from Numbers. [See Boolos 1986 (140).] Given these observations, we know from our work in §§4 and 5 above that Numbers suffices for the derivation of the basic laws of arithmetic.