2.4.tex

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

\begin{document}
We have,
\begin{lstlisting}
(car (cons x y))
(car (lambda (m) (m x y)))
((lambda (m) (m x y)) (lambda (p q) p))
((lambda (p q) p) x y)
x
\end{lstlisting}
We could define \lstinline!cdr! as follow,
\begin{lstlisting}
(define (cdr z)
  (z (lambda (p q) q)))
\end{lstlisting}
\end{document}