http://dswarmsikhttkg7jgsoyfiqpj3ighupfrvuz5ri3lu5q2dlqyrpgk7ad.onion/notes/frege-ancestral.html
The (week) ancestral relation \(R^+\) The week ancestral relation is the concept y is a member of the R-series beginning with x , ( BS , Part III, Proposition 99; GL , §81, and GG I, §46) \(b\) is a member of the R -series beginning with \(a\) if and only if either \(a\) bears the ancestral of \(R\) to \(b\) or \(a=b\). Formally, \[
R^{+}ab \equiv R^* ab \lor a =b
\] Frege’s definitions of ancestral finally allow him to define the natural numbers : \[
\mathbb{N}a\equiv...