\documentclass[fleqn,leqno]{article}
\usepackage{hypertlabook}
\pdftitle{ASCII Text}
\fixverbatim
\begin{popup}
\begin{verbatim*}
SimpleTC(R) ==
  LET RECURSIVE STC(_)
      STC(n) == IF n = 1 THEN R
                         ELSE STC(n-1) \cup STC(n-1) ** R
  IN  STC(Cardinality(NodesOf(R)))
\end{verbatim*}
\end{popup}
\makeasciipopup