\documentclass[fleqn,leqno]{article}
\usepackage{hypertlabook}
\pdftitle{ASCII Text}
\fixverbatim
\begin{popup}
\begin{verbatim*}
inBar == IF pc["P"] = "p2b" THEN ITail(in)
                            ELSE in

pcBar == [i \in {"P", "C"} |->
            CASE i = "P" -> CASE pc["P"] = "p2a" -> "p2"
                              [] pc["P"] = "p2b" -> "p3"
                              [] OTHER -> pc["P"]
              [] i = "C" -> pc["C"]    ]
\end{verbatim*}
\end{popup}
\makeasciipopup