diff --git a/books/bookvol4.pamphlet b/books/bookvol4.pamphlet
index ba28ffa..a9c639b 100644
--- a/books/bookvol4.pamphlet
+++ b/books/bookvol4.pamphlet
@@ -331,6 +331,17 @@ November 10, 2003 ((iHy))
 \eject
 \pagenumbering{arabic}
 \setcounter{chapter}{0} % Chapter 1
+\begin{quote}
+Confronting every new programmer learning a new language are
+\begin{itemize}
+\item The Cave of Artifacts
+\item The Forest of Tooling
+\item The Mountain of Language
+\item The Cloud Castle of Mindset
+\end{itemize}
+-- Daniel Higginbotham in Clojure for the Brave and True
+\end{quote}
+
 \section{What is the purpose of the HACKPI domain?}
 
 HACKPI is a hack provided for the benefit of the axiom interpreter.
@@ -2516,6 +2527,158 @@ that have slightly different semantics than their common lisp
 counterparts still exist in the system as macros due to this
 lisp. 
 
+\section{Changing GCL versions}
+
+Axiom lives on GNU Common Lisp. Axiom adds C code to the lisp image.
+Axiom caches versions to ensure that nothing breaks. Changing GCL
+versions has introduced subtle bugs at various times. The steps
+necessary to introduce a new version are
+
+\begin{enumerate}
+\item Add the latest GCL sources to Axiom
+\item Update the patches to the new version
+\item create diff -Naur patches to the gcl sources
+\item update lsp/Makefile.pamphlet to apply the patch at build
+\item add a new chunk to lsp/Makefile.pamphlet to build gcl-2.6.10
+\item Change the GCLVERSION to point at the new sources
+\item change the Makefile to match Makefile.pamphlet
+\end{enumerate}
+
+We assume in the following that \verb|$AXHOME| is the home directory and that
+Axiom lives in the silver subdirectory.
+
+In more detail these steps are:
+
+\begin{enumerate}
+\item Add the lateset GCL sources to Axiom
+\begin{enumerate}
+\item Download the latest GCL from gnu.org\\
+      For these instructions assume the file is 
+\begin{verbatim}
+      gcl-Version_2_6_10.tar.gz
+\end{verbatim}
+\item move the tar file into /tmp\\
+      We are going to make changes to the distribution via patches
+\item untar the file
+\begin{verbatim}
+      tar -zxf gcl-Version_2_6_10.tar.gz
+\end{verbatim}
+\item cd to the untarred directory
+\begin{verbatim}
+      cd gcl-Version_2_6_10
+\end{verbatim}
+\item rename the gcl directory\\
+      Camm follows a convention that the top level directory in the
+      tar file is called gcl. Since we maintain several past versions
+      we need to rename this and re-tar it
+\begin{verbatim}
+      mv gcl gcl-2.6.10
+\end{verbatim}
+\item rename gcl to use our naming convention
+\begin{verbatim}
+      tar -zcf gcl-2.6.10.tgz gcl-2.6.10
+\end{verbatim}
+\item We move the original, renamed, retarred file to the zip directory
+\begin{verbatim}
+      mv gcl-2.6.10.tgz $AXHOME/silver/zips
+\end{verbatim}      
+\item We have to make sure to include the new file in the git commit
+\begin{verbatim}
+     cd $AXHOME/silver
+\end{verbatim}      
+\item Tell git we care about the file
+\begin{verbatim}
+     git add zips/gcl-2.6.10.tgz
+\end{verbatim}
+\end{enumerate}
+\item Update the patches to the new version
+\begin{enumerate}
+\item find the previous patches
+\begin{verbatim}
+     ls $AXHOME/silver/zips/gcl-2.6.8pre7*patch
+\end{verbatim}
+\item for each patch do ( Step 3 ; Step 4 )
+\end{enumerate}
+\item create diff -Naur patches to the gcl sources
+\begin{enumerate}
+\item assume we are looking at gcl-2.6.8pre7.h.linux.defs.patch\\
+     The name tells us what file to patch. From the above we can see
+     that when Axiom builds GCL it will
+\begin{verbatim}
+        cd lsp/gcl-2.6.8pre7
+\end{verbatim}
+     because GCL is built by the lsp/Makefile.pamphlet. That Makefile
+     will do a
+\begin{verbatim}
+        cd h
+        patch <gcl-2.6.8pre7.h.linux.defs.patch
+\end{verbatim}
+     which will apply the patch .... So we need to make a patch
+\item move to the subdirectory containing the file
+\begin{verbatim}
+      cd /tmp/gcl-Version_2_6_10/gcl-2.6.10/h
+\end{verbatim}
+\item edit the 'linux.defs' file to create the proper patch
+\item save the changed file as linux.defs.tpd
+\item in a shell, create a diff -Naur patch by 
+\begin{verbatim}
+      diff -Naur linux.defs linux.defs.tpd >gcl-2.6.10.h.linux.defs.patch
+\end{verbatim}
+\item move it to the zips directory
+\begin{verbatim}
+      mv gcl-2.6.10.h.linux.defs.patch $AXHOME/silver/zips
+      cd $AXHOME/silver
+      git add zips/gcl-2.6.10.h.linux.defs.patch
+\end{verbatim}
+\end{enumerate}
+\item update lsp/Makefile.pamphlet to apply the patch at build
+\begin{enumerate}
+\item edit lsp/Makefile.pamphlet
+\item search for chunk \verb|gcl-2.6.8pre7.h.linux.defs.patch|
+\item copy the chunk and name the new chunk 
+\verb|gcl-2.6.10.h.linux.defs.patch|
+\end{enumerate}
+\item add a new chunk to lsp/Makefile.pamphlet to build gcl-2.6.10
+\begin{enumerate}
+\item find the subsection ``The GCL-2.6.8pre7 stanza''
+\item make a copy named ``The GCL-2.6.10 stanza''
+\item add the new patches
+\item tell git we care
+\begin{verbatim}
+      cd $AXHOME/silver
+      git add lsp/Makefile.pamphlet
+\end{verbatim}
+\end{enumerate}
+\item Change the GCLVERSION to point at the new sources
+\begin{enumerate}
+\item emacs \verb|$AXHOME/silver/Makefile.pamphlet|
+\item search for \verb|#GCLVERSION|, a Makefile comment line
+\item the last line is uncommented. Assume it reads GCLVERSION=gcl-2.6.8pre7\\
+      gcl-2.6.8pre7 was is the name of the current version we are
+      replacing. We will use this name in the next step
+\item put a \# in front of the GCLVERSION variable to comment it out\\
+      We maintain the list of old, working patches. We also remember the
+      names of the prior GCLVERSIONS in case we have to back up
+\item Add a new line reading:
+\begin{verbatim}
+         GCLVERSION=gcl-2.6.10
+\end{verbatim}
+      This will cause Axiom to untar this tgz file to get the sources
+      and apply the corresponding patches
+\end{enumerate}
+\item change the Makefile to match Makefile.pamphlet
+\begin{itemize}
+\item compile the tangle program
+\begin{verbatim}
+      ( cd books ; gcc -o tangle tangle.c )
+\end{verbatim}
+\item use books/tangle to extract the new Makefile
+\begin{verbatim}
+      books/tangle Makefile.pamphlet >Makefile
+\end{verbatim}
+\end{itemize}
+\end{enumerate}
+
 \section{Literate Programming}
 The Axiom source code was originally developed at IBM Research.
 It was sold to The Numerical Algorithms Group (NAG) and was on
diff --git a/changelog b/changelog
index 90784b9..2e0f1b4 100644
--- a/changelog
+++ b/changelog
@@ -1,3 +1,5 @@
+20140710 tpd src/axiom-website/patches.html 20140710.02.tpd.patch
+20140710 tpd books/bookvol4 add a section on changing GCL2 versions
 20140710 tpd src/axiom-website/patches.html 20140710.01.tpd.patch
 20140710 tpd Makefile remove leftover pdf files on clean
 20140708 tpd src/axiom-website/patches.html 20140708.02.tpd.patch
diff --git a/patch b/patch
index 2f744f5..dcd3e72 100644
--- a/patch
+++ b/patch
@@ -1 +1,4 @@
-Makefile remove leftover pdf files on clean
+books/bookvol4 add a section on changing GCL2 versions
+
+The process of moving GCL2 versions is reasonably simple.
+It is documented in detail.
diff --git a/src/axiom-website/patches.html b/src/axiom-website/patches.html
index af1909a..ccfc19d 100644
--- a/src/axiom-website/patches.html
+++ b/src/axiom-website/patches.html
@@ -4538,6 +4538,8 @@ src/algebra/Makefile add LeftOreRing
 books/ps/v102leftorering.eps add missing image file
 <a href="patches/20140710.01.tpd.patch">20140710.01.tpd.patch</a>
 Makefile remove leftover pdf files on clean
+<a href="patches/20140710.02.tpd.patch">20140710.02.tpd.patch</a>
+books/bookvol4 add a section on changing GCL2 versions
  </body>
 </html>