What is "the set of all polynomials in $\pi$"? From Ian Stewart's Galois Theory (2015, 4e, p. 20):

What does, for example, "the set of all polynomials in $\pi$" mean?

The set of all polynomials in $\pi$ with rational coefficients is the set of real numbers of the form $p(\pi)$, where $p(x)$ is a polynomial with rational coefficients; that is, it is the set $\{ p(\pi) \mid p(x) \in \mathbb{Q}[x] \}$.
