1.1 --- a/doc-src/TutorialI/preface.tex	Mon May 13 09:02:13 2002 +0200
     1.2 +++ b/doc-src/TutorialI/preface.tex	Mon May 13 10:40:59 2002 +0200
     1.3 @@ -52,11 +52,11 @@
     1.4  sessions are now run from within David Aspinall's\index{Aspinall, David}
     1.5  wonderful user interface, \hfootref{http://www.proofgeneral.org/}{Proof
     1.6    General}, even together with the
     1.7 -\hfootref{http://www.fmi.uni-passau.de/~wedler/x-symbol/}{X-Symbol} package
     1.8 -for XEmacs.  This book says very little about Proof General, which has its own
     1.9 -documentation.  In order to run Isabelle, you will need a Standard ML
    1.10 -compiler.  We recommend \hfootref{http://www.polyml.org/}{Poly/ML}, which is
    1.11 -free and gives the best performance.  The other fully supported compiler is
    1.12 +\hfootref{http://x-symbol.sourceforge.net}{X-Symbol} package for XEmacs.  This
    1.13 +book says very little about Proof General, which has its own documentation.
    1.14 +In order to run Isabelle, you will need a Standard ML compiler.  We recommend
    1.15 +\hfootref{http://www.polyml.org/}{Poly/ML}, which is free and gives the best
    1.16 +performance.  The other fully supported compiler is
    1.17  \hfootref{http://cm.bell-labs.com/cm/cs/what/smlnj/index.html}{Standard ML of
    1.18    New Jersey}.
    1.19