 Hume’s Principle is taken to be a contextual definition of \(\#F\) when the latter is assumed as a primitive notion governed by the principle: the principle doesn’t explicitly define ‘\(\#F\)’, but contextually defines it by defining contexts (in this case, identity statements) in which it  occurs.[7]  As we shall see, Hume’s Principle is the basic principle upon which Frege forged his development of the theory of natural numbers. In Gl, Frege sketched the derivations of the basic laws of number theory from Hume’s Principle; these sketches were developed into more rigorous proofs in Gg I. We will examine these derivations in the following sections.