ABSTRACT
The set S of Pisot (or Pisot-Vijayaraghavan) numbers consists of those real algebraic integers θ > 1 all of whose other conjugates lie strictly inside the unit circle. As was shown by Salem [9], the set S is a closed subset of the reals. Thus, given any real number x ∉ S, the distance from x to S, d ( x , S ) : = min { | x − θ | : θ ∈ S } , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203747018/bef25d74-ef02-4914-ac4f-27ec89fc30ac/content/eq116.tif"/>