diff --git a/books/tangle.c b/books/tangle.c
index 04a2e20..5eb6c11 100644
--- a/books/tangle.c
+++ b/books/tangle.c
@@ -5,6 +5,7 @@
 #include <sys/mman.h>
 #include <fcntl.h>
 
+// set this to 3 for further information
 #define DEBUG 0
 
 /* forward reference for the C compiler */
@@ -34,15 +35,19 @@ int printline(int i, int length) {
 int foundchunk(int i, char *chunkname) {
   if ((strncmp(&buffer[i+14],chunkname,strlen(chunkname)) == 0) &&
       (buffer[i+13] == '{') &&
-      (buffer[i+14+strlen(chunkname)] == '}')) return(1);
+      (buffer[i+14+strlen(chunkname)] == '}')) {
+    if (DEBUG==3) { printf("foundchunk(%s)\n",chunkname); }
+    return(1); 
+  }
   return(0);
 }
 
 /* handle end{chunk}   */
 /* is it really an end? */
-int foundEnd(int i) {
+int foundEnd(int i, char* chunkname) {
   if ((buffer[i] == '\\') && 
       (strncmp(&buffer[i+1],"end{chunk}",10) == 0)) {
+    if (DEBUG==3) { printf("foundEnd(%s)\n",chunkname); }
     return(1); 
   }
   return(0);
@@ -75,18 +80,16 @@ int printchunk(int i, int chunklinelen, char *chunkname) {
   int linelen;
   char *getname;
   int getlen = 0;
+  if (DEBUG==3) { printf("===   \\start{%s}   ===\n",chunkname); }
   for (k=i+chunklinelen+1; ((linelen=nextline(k)) != -1); ) {
-    if (DEBUG==2) { 
-      printf(">>>>"); printline(k,linelen); printf("<<<<\n"); 
-    }
     if ((getlen=foundGetchunk(k,linelen)) > 0) {
        getname = getChunkname(k,getlen);
        getchunk(getname);
        free(getname);
        k=k+getlen+12l;
     } else {
-    if ((linelen >= 11) && (foundEnd(k) == 1)) {
-      if (DEBUG) { printf("=================\\end{%s}\n",chunkname); }
+      if ((linelen >= 11) && (foundEnd(k,chunkname) == 1)) {
+      if (DEBUG==3) { printf("===   \\end{%s}   ===\n",chunkname); }
       return(k+12);
     } else {
       if (DEBUG==2) { 
@@ -108,12 +111,13 @@ int getchunk(char *chunkname) {
   int j;
   int linelen;
   int chunklen = strlen(chunkname);
+  if (DEBUG==3) { printf("getchunk(%s)\n",chunkname); }
   for (i=0; ((linelen=nextline(i)) != -1); ) {
     if (DEBUG==2) { 
       printf("----"); printline(i,linelen); printf("----\n"); 
     }
     if ((linelen >= chunklen+15) && (foundchunk(i,chunkname) == 1)) {
-      if (DEBUG) {
+      if (DEBUG==2) {
          fprintf(stderr,"=================\\getchunk(%s)\n",chunkname); 
       }
       i=printchunk(i,linelen,chunkname);
@@ -121,7 +125,7 @@ int getchunk(char *chunkname) {
       i=i+linelen+1;
     }
   }
-  if (DEBUG) { 
+  if (DEBUG==2) { 
     fprintf(stderr,"=================getchunk returned=%d\n",i); 
   }
   return(i);
diff --git a/changelog b/changelog
index dd1b005..6ac2d76 100644
--- a/changelog
+++ b/changelog
@@ -1,3 +1,5 @@
+20140629 tpd src/axiom-website/patches.html 20140629.06.tpd.patch
+20140629 tpd books/tangle.c improve the debugging output (DEBUG==3)
 20140629 tpd src/axiom-website/patches.html 20140629.05.tpd.patch
 20140629 tpd books/bookvol10.3 add information to SingleInteger
 20140629 tpd src/axiom-website/patches.html 20140629.04.tpd.patch
diff --git a/patch b/patch
index 63f0393..40f2fed 100644
--- a/patch
+++ b/patch
@@ -1,10 +1,6 @@
-books/bookvol10.3 add information to SingleInteger
+books/tangle.c improve the debugging output (DEBUG==3)
+
+Improve the debugging output (DEBUG==3) so that it is obvious
+what chunk is being expanded. It also shows the expanded output
+delimited by begin/end markers.
 
-This type represents finite (machine) precision integers which wrap
-around at a machine dependent value. However, {\bf SingleInteger} has
-type {\bf EntireRing} which should have no non-zero divisors. But
-\[ (2**16:SINT)**2 = 0\]
-on a 32 bit machine. Using {\bf SingleInteger} is a pragmatic
-efficiency choice. In this condition, Axiom will complain that the
-result is not of type FIXNUM, which is the Common Lisp type for
-machine integers.
diff --git a/src/axiom-website/patches.html b/src/axiom-website/patches.html
index 22c699c..d1a1461 100644
--- a/src/axiom-website/patches.html
+++ b/src/axiom-website/patches.html
@@ -4512,6 +4512,8 @@ src/axiom-website/documentation.html add McNamara quote
 Makefile default to notests for users
 <a href="patches/20140629.05.tpd.patch">20140629.05.tpd.patch</a>
 books/bookvol10.3 add information to SingleInteger
+<a href="patches/20140629.06.tpd.patch">20140629.06.tpd.patch</a>
+books/tangle.c improve the debugging output (DEBUG==3)
  </body>
 </html>