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+\documentclass{article}
+\usepackage{axiom}
+\begin{document}
+\title{\$SPAD/src/input is.input}
+\author{The Axiom Team}
+\maketitle
+\begin{abstract}
+\end{abstract}
+\eject
+\tableofcontents
+\eject
+\section{License}
+<<license>>=
+--Copyright The Numerical Algorithms Group Limited 1991.
+@
+<<*>>=
+<<license>>
+
+--  This is the 3n + 1 function:   f(n) = n/2    if n is even,
+--                                        3n + 1 otherwise
+--
+-- It can obviously be coded as
+--  f n ==
+--    even? n => n quo 2
+--    3 * n + 1
+
+-- but we code using the pattern matching syntax:
+-- f n ==
+--    n is 2*m% => m%
+--    3 * n + 1
+
+-- The 'integer' is to return an integer instead of a polynomial
+f n ==
+   not empty?(u := Is(n, 2*m%)) => integer eval(m%, u)
+   3 * n + 1
+
+)set stream showall on
+
+-- The function g generates the stream of the repeated applications of f
+g(n:INT):STREAM(INT) == generate(f, n)
+
+-- There is a conjecture that g(n) gets into the cycle (1 4 2)
+-- for every n
+s := g 27
+extend(s, 150)
+@
+\eject
+\begin{thebibliography}{99}
+\bibitem{1} nothing
+\end{thebibliography}
+\end{document}