 Frege next defines the relation x is an ancestor of y in the R-series. This new relation is called ‘the ancestral of the relation R’ and we henceforth designate this relation as \(R^*\). Frege first defined the ancestral of a relation R in Begr (Part III, Proposition 76), though the word ‘ancestral’ comes to us from Russell and Whitehead. Frege’s phrase for the ancestral is: “\(x\) comes before \(y\) in the \(R\)-series”; alternatively, “\(y\) follows \(x\) in the \(R\)-series”. (See also Gl, §79, and Gg I, §45.) The intuitive idea is easily grasped if we consider the relation \(x\) is the father of \(y\). Suppose that \(a\) is the father of \(b\), that \(b\) is the father of \(c\), and that \(c\) is the father of \(d\). Then ‘\(x\) is an ancestor of \(y\) in the fatherhood-series’ is defined so that \(a\) is an ancestor of \(b\), \(c\), and \(d\), that \(b\) is an ancestor of \(c\) and \(d\), and that \(c\) is an ancestor of \(d\).