2.47.tex

\documentclass[a4paper,12pt]{article}
\usepackage{listings}
\lstset{language=Lisp}

\begin{document}
For the first representation
\begin{lstlisting}
(define (make-frame origin edge1 edge2)
  (list origin edge1 edge2))
(define origin-frame car)
(define edge1-frame cadr)
(define edge2-frame caddr)
\end{lstlisting}
For the second one,
\begin{lstlisting}
(define (make-frame origin edge1 edge2)
  (cons origin (cons edge1 edge2)))
(define origin-frame car)
(define edge1-frame cadr)
(define edge2-frame cddr)
\end{lstlisting}
\end{document}