install new script latexdiff

git-svn-id: svn://tug.org/texlive/trunk@16379 c570f23f-e606-0410-a88d-b1316a301751

63 files changed, 16655 insertions, 8 deletions

diff --git a/Build/source/texk/texlive/linked_scripts/Makefile.am b/Build/source/texk/texlive/linked_scripts/Makefile.am
index 913f41c6032..a64a07b55a3 100644
--- a/Build/source/texk/texlive/linked_scripts/Makefile.am
+++ b/Build/source/texk/texlive/linked_scripts/Makefile.am
@@ -66,6 +66,9 @@ nobase_dist_script_SCRIPTS = \
 	fragmaster/fragmaster.pl \
 	glossaries/makeglossaries \
 	latex2man/latex2man \
+	latexdiff/latexdiff.pl \
+	latexdiff/latexdiff-vc \
+	latexdiff/latexrevise \
 	latexmk/latexmk.pl \
 	listings-ext/listings-ext.sh \
 	mkjobtexmf/mkjobtexmf.pl \
diff --git a/Build/source/texk/texlive/linked_scripts/Makefile.in b/Build/source/texk/texlive/linked_scripts/Makefile.in
index 94c58fad1e7..4db676fc95f 100644
--- a/Build/source/texk/texlive/linked_scripts/Makefile.in
+++ b/Build/source/texk/texlive/linked_scripts/Makefile.in
@@ -215,6 +215,9 @@ nobase_dist_script_SCRIPTS = \
 	fragmaster/fragmaster.pl \
 	glossaries/makeglossaries \
 	latex2man/latex2man \
+	latexdiff/latexdiff.pl \
+	latexdiff/latexdiff-vc \
+	latexdiff/latexrevise \
 	latexmk/latexmk.pl \
 	listings-ext/listings-ext.sh \
 	mkjobtexmf/mkjobtexmf.pl \
diff --git a/Build/source/texk/texlive/linked_scripts/latexdiff/latexdiff-vc b/Build/source/texk/texlive/linked_scripts/latexdiff/latexdiff-vc
new file mode 100755
index 00000000000..3e9a3f246de
--- /dev/null
+++ b/Build/source/texk/texlive/linked_scripts/latexdiff/latexdiff-vc
@@ -0,0 +1,430 @@
+#!/usr/bin/perl -w
+# Place the following 2 lines at beginning to make script independent of location of perl
+#eval 'exec perl -w -S $0 ${1+"$@"}'
+#    if 0; # not running under some shell
+#
+# latexdiff-vc  - wrapper script for applying latexdiff to rcs managed files
+#                 and for automatised creation of postscript or pdf from difference file
+#
+#   Copyright (C) 2005  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#   Contributors: S Utcke, H Bruyninckx
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# version 0.25:
+#   - bbl is allowed as alternative extension (instead of .tex)
+#   
+use Getopt::Long ;
+use Pod::Usage qw/pod2usage/ ;
+use File::Temp qw/tempdir/ ;
+use File::Basename qw/dirname/;
+use strict ;
+
+# Option names
+my ($version,$help,$postscript,$pdf,$force,$dir,$cvs,$rcs,$svn,$diffcmd,$patchcmd,@revs);
+# Preset Variables
+my $latexdiff="latexdiff"; # Program for making the comparison
+my $vc="";
+my $tempdir=tempdir(CLEANUP => 1);
+# Variables
+my ($file1,$file2,$diff,$diffbase,$answer,$options,$infile,$append,$dirname,$cwd);
+my (@files,@ldoptions,@tmpfiles,@ptmpfiles,@difffiles); # ,
+
+
+Getopt::Long::Configure('pass_through','bundling');
+
+GetOptions('revision|r:s' => \@revs,
+           'cvs' => \$cvs,
+           'rcs' => \$rcs,
+           'svn' => \$svn,
+           'dir|d:s' => \$dir,
+           'postscript|ps' => \$postscript,
+           'pdf' => \$pdf,
+           'force' => \$force,
+           'version' => \$version,
+	   'help|h' => \$help);
+
+if ( $help ) {
+  pod2usage(1) ;
+}
+
+if ( $version ) {
+  die "This is LATEXDIFF-VC 0.25\n" ;
+}
+
+if ( $cvs ) {
+  $vc="CVS";
+}
+if ( $rcs ) {
+  die "Cannot specify more than one of --cvs, --rcs or --svn." if ($vc);
+  $vc="RCS";
+}
+if ( $svn ) {
+  die "Cannot specify more than one of --cvs, --rcs or --svn." if ($vc);
+  $vc="SVN";
+}
+
+# check whether the first file name got misinterpreted as an option to an empty -r option
+if ( @revs && -f $revs[$#revs] ) {
+  unshift @ARGV,$revs[$#revs];
+  $revs[$#revs]="";
+}
+# check whether the first file name got misinterpreted as an option to an empty -d option
+if ( defined($dir) && -f $dir ) {
+  unshift @ARGV,$dir;
+  $dir="";
+}
+
+$file2=pop @ARGV;
+( defined($file2) && $file2 =~ /\.(tex|bbl)$/ ) or pod2usage("Must specify at least one tex or bbl file");
+
+if (! $vc && scalar(@revs)>0 ) {
+  # have to guess $vc
+  # check whether we have a special name
+  if ( $0 =~ /-cvs$/ ) {
+    $vc="CVS";
+  } elsif ( $0 =~ /-rcs$/ ) {
+    $vc="RCS";
+  } elsif ( $0 =~ /-svn$/ ) {
+    $vc="SVN";
+  } elsif ( -e "CVSROOT" || defined($ENV{"CVSROOT"}) ) {
+    print STDERR "Guess you are using CVS ...\n";
+    $vc="CVS";
+  } elsif ( -e "$file2,v" ) {
+    print STDERR "Guess you are using RCS ...\n";
+    $vc="RCS";
+  } elsif ( -d ".svn" ) {
+    print STDERR "Guess you are using SVN ...\n";
+    $vc="SVN";
+  } else {
+    print STDERR "Cannot figure out version control system, so I default to CVS\n";
+    $vc="CVS";
+  }
+}
+
+if (defined($dir) && $dir=~/^\.\/?/ ) {
+  print STDERR "You wrote selected -dir=.  but you do not really like to do that, do you ?\n";
+  exit 10
+}
+
+if ( scalar(@revs)>0 ) {
+  if ( $vc eq "CVS" ) { 
+    $diffcmd  = "cvs diff -u -r"; 
+    $patchcmd = "patch -R -p0";
+  } elsif ( $vc eq "RCS" ) {
+    $diffcmd  = "rcsdiff -u -r";  
+    $patchcmd = "patch -R -p0";
+  } elsif ( $vc eq "SVN" ) {
+    $diffcmd  = "svn diff -r ";  
+    $patchcmd = "patch -R -p0";
+  } else {
+    print STDERR "Unknown versioning system $vc \n";
+    exit 10;
+  }
+}
+
+
+# make file list (last arguments), initial arguments have to be passed to latexdiff
+# We assume an argument is a valid file rather than a latexdiff argument
+# if it has extension .tex or .bbl
+
+@files=($file2);
+while( $file1=pop @ARGV ) {
+  if ( $file1 =~ /\.(tex|bbl)$/ ) {
+    # $file1 looks like a valid file name and is prepended to file list
+    unshift @files, $file1 ;
+  } else {
+    # $file1 looks like an option for latexdiff, push it back to argument stack
+    unshift @ldoptions, $file1 ;
+  }
+}
+
+if ( scalar(@revs) == 0 ) {
+  pod2usage("When -r option is not used, two .tex files (old and new) must be given on the command line") unless @files==2;
+    #  compare two files
+  $file1=shift @files ;
+}
+
+if ( scalar(@revs) == 2 ) {
+  $append = "-diff$revs[0]-$revs[1]";
+} elsif ( scalar(@revs) == 1 || $revs[0] ) {
+  $append = "-diff$revs[0]";
+} else {
+  $append = "-diff";
+}
+
+if ( defined ($dir) && ! $dir ) {
+  # bare -d option => choose directory name
+  ($dir=$append) =~ s/^-//;
+}
+
+if ( ($vc eq "SVN" || $vc eq "CVS") && scalar(@revs)) {
+  length($revs[$#revs]) > 0 or $revs[$#revs]="HEAD";
+  length($revs[0]) > 0 or $revs[0]="HEAD";
+}
+
+#exit ; 
+
+
+# cycle through all files
+
+@difffiles=();
+while ( $infile=$file2=shift @files ) {
+  print STDERR "Working on  $infile \n";
+  if ( scalar(@revs) == 1 ) {
+    ($file1=$infile) =~ s/\.(tex|bbl)/-oldtmp-$$.$1/ ;
+    push @tmpfiles,$file1;
+    # compare file with previous version ($revs[0]="") or specified version
+    system("$diffcmd$revs[0] $infile| $patchcmd -o$file1") ;
+  } elsif ( scalar(@revs) == 2 ) {
+    ($file1=$infile) =~ s/\.(tex|bbl)/-oldtmp-$$.$1/ ;
+    $file2 =~ s/\.(tex|bbl)/-newtmp-$$.$1/ ;
+    push @tmpfiles,$file2;
+    system("$diffcmd$revs[1] $infile | $patchcmd -o$file2")  ;
+    system("$diffcmd$revs[0] $infile | $patchcmd -o$file1")  ;
+  }
+
+  if ( -z $file1 || -z $file2) {
+    print STDERR "One or both of the files to compare are empty. Possibly something went wrong in the retrieval of older versions. Aborting ...\n" ;
+    exit(10);
+  }
+
+  # Get name of difference file
+  if ( defined($dir) ) {
+    $diff="$dir/$infile" ; 
+  } else {
+    ($diff=$infile) =~ s/\.(tex|bbl)$/$append.$1/ ;
+  }
+  # make directories if needed
+  $dirname=dirname($diff) ;
+  system("mkdir -p $dirname") unless ( -e $dirname );
+
+  # Remaining options are passed to latexdiff
+  $options = join(" ",@ldoptions);
+
+  if ( -e $diff && ! $force ) {
+    print STDERR "OK to overwrite existing file $diff (y/n)? ";
+    $answer = <STDIN> ;
+    unless ($answer =~ /^y/i ) {
+      unlink @tmpfiles;
+      die "Abort ... " ;
+    }
+  }
+  print "Running $latexdiff\n";
+  unless ( system("$latexdiff $options $file1 $file2 > $diff") == 0 ) { 
+    print STDERR  "Something went wrong in $latexdiff. Deleting $diff and abort\n" ; unlink $diff ; exit(5) 
+  };
+  print "Generated difference file $diff\n";
+
+  if ( ( $postscript or $pdf ) and !( scalar(@revs) && greptex( qr/\\document(?:class|style)/ , $diff ) ) ) {
+    # save filename for later processing if postscript or pdf conversion is requested and either two-file mode was used (scalar(@revs)==0) or the diff file contains documentclass statement (ie. is a root document)
+    push @difffiles, $diff ;
+  }
+  
+  unlink @tmpfiles;
+}
+
+foreach $diff ( @difffiles ) {
+  chomp($cwd=(`pwd`));
+  if  (defined($dir)) {
+    ( $diff =~ s/$dir\/?// ) ;
+    chdir $dir ; 
+  }
+  @ptmpfiles=();
+  ( $diffbase=$diff) =~ s/\.(tex)$// ;
+
+  # adapt magically changebar styles to [pdftex] display driver if pdf output was selected
+  if ( $pdf ) {
+    system("sed \"s/Package\\[dvips\\]/Package[pdftex]/\" $diff > $diff.tmp$$ ; \\mv $diff.tmp$$ $diff");
+  }
+  print STDERR "PDF: $pdf Postscript: $postscript cwd $cwd\n";
+
+  if ( system("grep -q \'^[^%]*\\\\bibliography\' $diff") == 0 ) { 
+    if ( $postscript) {
+      system("latex --interaction=batchmode $diff; bibtex $diffbase");
+      push @ptmpfiles, "$diffbase.bbl","$diffbase.bbl" ; 
+    } elsif ( $pdf ) {
+      system("pdflatex --interaction=batchmode $diff; bibtex $diffbase");
+      push @ptmpfiles, "$diffbase.bbl","$diffbase.bbl" ; 
+    }
+  }
+
+  if ( $postscript ) {
+    my $dvi="$diffbase.dvi";
+    my $ps="$diffbase.ps";
+
+    system("latex --interaction=batchmode $diff; latex $diff; dvips -o $ps $dvi");
+    push @ptmpfiles, "$diffbase.aux","$diffbase.log",$dvi ;
+    print "Generated postscript file $ps\n";
+  } 
+  elsif ( $pdf ) {
+    system("pdflatex --interaction=batchmode $diff; pdflatex $diff");
+    push @ptmpfiles, "$diffbase.aux","$diffbase.log";
+  }
+  unlink @ptmpfiles;
+  chdir $cwd;
+}
+
+# greptex returns 1 if regex is not matched in filename
+# 0 if there is a match
+sub greptex {
+  my ($regex,$filename)=@_;
+  my ($i)=0;
+  open (FH, $filename) or die("Couldn't open $filename: $!");
+  while (<FH>) {
+    next if /^\s*%/;    # skip comment lines
+    if ( m/$regex/ ) {
+      close(FH);
+      return(0);
+    }
+    # only scan 25 lines
+    $i++;    
+    last if $i>25 ;
+  }
+  close(FH);
+  return(1);
+}
+
+
+=head1 NAME
+
+latexdiff-vc - wrapper script that calls latexdiff for different versions of a file under version management (CVS, RCS or SVN)
+
+=head1 SYNOPSIS
+
+B<latexdiff-vc> [ F<latexdiff-options> ] [ F<latexdiff-vc-options> ]  B<-r> [F<rev1>] [B<-r> F<rev2>]  F<file1.tex> [ F<file2.tex> ...]
+
+ or
+
+B<latexdiff-vc> [ F<latexdiff-options> ]  [ F<latexdiff-vc-options> ][ B<--postscript> | B<--pdf> ]  F<old.tex> F<new.tex>
+
+=head1 DESCRIPTION
+
+I<latexdiff-vc> is a wrapper script that applies I<latexdiff> to a
+file, or multiple files under version control (CVS or RCS), and optionally runs the
+sequence of C<latex> and C<dvips> or C<pdflatex> commands necessary to
+produce pdf or postscript output of the difference tex file(s). It can
+also be applied to a pair of files to automatise the generation of difference
+file in postscript or pdf format.
+
+=head1 OPTIONS
+
+=over 4
+
+=item B<--rcs>, B<--svn>, or B<--cvs>
+
+Set the version system. 
+If no version system is specified, latexdiff-vc will venture a guess.
+
+latexdiff-cvs and latexdiff-rcs are variants of latexdiff-vc which default to 
+the respective versioning system. However, this default can still be overridden using the options above.
+
+=item B<-r>, B<-r> F<rev> or B<--revision>, B<--revision=>F<rev>
+
+Choose revision (under RCS, CVS or SVN). One or two B<-r> options can be
+specified, and the resulting in different behaviour:
+
+=over 4
+
+=item B<latexdiff-vc> -r F<file.tex> ...
+
+compares F<file.tex> with the most recent version checked into RCS.
+
+=item B<latexdiff-vc> -r F<rev1> F<file.tex> ...
+
+compares F<file.tex> with revision F<rev1>.
+
+=item B<latexdiff-vc> -r F<rev1> -r F<rev2> F<file.tex> ...
+
+compares revisions F<rev1> and F<rev2> of F<file.tex>.
+
+Multiple files can be specified for all of the above options. All files must have the
+extension C<.tex>, though.
+
+=item B<latexdiff-vc>  F<old.tex> F<new.tex>
+
+compares two files.
+
+=back
+
+The name of the difference file is generated automatically and
+reported to stdout.
+
+=item B<-d> or B<--dir>  B<-d> F<path> or B<--dir=>F<path>
+
+Rather than appending the string C<diff> and optionally the version
+numbers given to the output-file, this will prepend a directory name C<diff> 
+to the
+original filename, creating the directory and subdirectories should they not exist already.  This is particularly useful in order to clone a
+complete directory hierarchy.  Optionally, a pathname F<path> can be specified, which is prepended instead of C<diff>.
+
+=item B<--ps> or B<--postscript>
+
+Generate postscript output from difference file.  This will run the
+sequence C<latex; latex; dvips> on the difference file (do not use
+this option in the rare cases, where three C<latex> commands are
+required if you care about correct referencing).  If the difference
+file contains a C<\bibliography> tag, run the sequence C<latex;
+bibtex; latex; latex; dvips>.
+
+=item B<--pdf>
+
+Generate pdf output from difference file using C<pdflatex>. This will
+run the sequence C<pdflatex; pdflatex> on the difference file, or
+C<pdflatex; bibtex; pdflatex; pdflatex> for files requiring bibtex.
+
+=item B<--force>
+
+Overwrite existing diff files without asking for confirmation. Default 
+behaviour is to ask for confirmation before overwriting an existing difference
+file.
+
+=item B<--help> or
+B<-h>
+
+Show help text
+
+=item B<--version>
+
+Show version number
+
+=back
+
+All other options are passed on to C<latexdiff>.
+
+=head1 SEE ALSO
+
+L<latexdiff>
+
+=head1 PORTABILITY
+
+I<latexdiff-vc> uses external commands and is therefore
+limited to Unix-like systems. It also requires the RCS version control
+system and latex to be installed on the system.  Modules from Perl 5.8
+or higher are required.
+
+
+=head1 AUTHOR
+
+Copyright (C) 2005 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+Contributors: S Utcke, H Bruyninckx
+
+=cut
+
diff --git a/Build/source/texk/texlive/linked_scripts/latexdiff/latexdiff.pl b/Build/source/texk/texlive/linked_scripts/latexdiff/latexdiff.pl
new file mode 100755
index 00000000000..03c70c3ac4e
--- /dev/null
+++ b/Build/source/texk/texlive/linked_scripts/latexdiff/latexdiff.pl
@@ -0,0 +1,3240 @@
+#!/usr/bin/perl -w
+# latexdiff - differences two latex files on the word level
+#             and produces a latex file with the differences marked up.
+#
+#   Copyright (C) 2004-2007  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# Version 0.5  A number of minor improvements based on feedback
+#              Deleted blocks are now shown before added blocks
+#              Package specific processing
+#
+# Version 0.43 unreleased typo in list of styles at the end
+#              Add protect to all \cbstart, \cbend commands
+#              More robust substitution of deleted math commands
+#
+# Version 0.42 November 06  Bug fixes only
+#
+# Version 0.4   March 06 option for fast differencing using UNIX diff command, several minor bug fixes (\par bug, improved highlighting of textcmds)
+#
+# Version 0.3   August 05 improved parsing of displayed math, --allow-spaces 
+#               option, several minor bug fixes
+#
+# Version 0.25  October 04 Fix bug with deleted equations, add math mode commands to safecmd, add | to allowed interpunctuation signs
+# Version 0.2   September 04 extension to utf-8 and variable encodings
+# Version 0.1   August 04    First public release
+
+# Inserted block for stand-alone version replaces
+# use Algorithm::Diff qw(traverse_sequences);
+# in standard version
+# The following BEGIN block contains a verbatim copy of
+# Ned Konz' Algorithm::Diff package version 1.15 except
+# that all POD documentation has been stripped out.
+# I encourage you to download and install the Algorithm::Diff
+# package and use the standard latexdiff version instead
+# (current distribution available from http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15
+#  the most recent version can be found via  http://search.cpan.org/search?module=Algorithm::Diff )
+# Please note that the LICENCSE for Algorithm::Diff :
+#   "Copyright (c) 2000-2002 Ned Konz.  All rights reserved.
+#    This program is free software;
+#    you can redistribute it and/or modify it under the same terms
+#    as Perl itself."
+# The stand-alone version of latexdiff is provided as a convenience
+# for latex users with no knowledge of PERL who do not wish to install
+# additional packages to be able to use latexdiff.  If you believe
+# the inlining of Algorithm::Diff violates its license please contact
+# me and I will modify the latexdiff distribution accordingly.
+# Frederik Tilmann (tilmann@esc.cam.ac.uk)
+BEGIN { 
+package Algorithm::Diff;
+use strict;
+use vars qw($VERSION @EXPORT_OK @ISA @EXPORT);
+use integer;    # see below in _replaceNextLargerWith() for mod to make
+                # if you don't use this
+require Exporter;
+@ISA       = qw(Exporter);
+@EXPORT    = qw();
+@EXPORT_OK = qw(LCS diff traverse_sequences traverse_balanced sdiff);
+$VERSION = sprintf('%d.%02d so', (q$Revision: 1.15 $ =~ /\d+/g));
+
+# McIlroy-Hunt diff algorithm
+# Adapted from the Smalltalk code of Mario I. Wolczko, <mario@wolczko.com>
+# by Ned Konz, perl@bike-nomad.com
+
+
+# Create a hash that maps each element of $aCollection to the set of positions
+# it occupies in $aCollection, restricted to the elements within the range of
+# indexes specified by $start and $end.
+# The fourth parameter is a subroutine reference that will be called to
+# generate a string to use as a key.
+# Additional parameters, if any, will be passed to this subroutine.
+#
+# my $hashRef = _withPositionsOfInInterval( \@array, $start, $end, $keyGen );
+
+sub _withPositionsOfInInterval
+{
+	my $aCollection = shift;    # array ref
+	my $start       = shift;
+	my $end         = shift;
+	my $keyGen      = shift;
+	my %d;
+	my $index;
+	for ( $index = $start ; $index <= $end ; $index++ )
+	{
+		my $element = $aCollection->[$index];
+		my $key = &$keyGen( $element, @_ );
+		if ( exists( $d{$key} ) )
+		{
+			unshift ( @{ $d{$key} }, $index );
+		}
+		else
+		{
+			$d{$key} = [$index];
+		}
+	}
+	return wantarray ? %d : \%d;
+}
+
+# Find the place at which aValue would normally be inserted into the array. If
+# that place is already occupied by aValue, do nothing, and return undef. If
+# the place does not exist (i.e., it is off the end of the array), add it to
+# the end, otherwise replace the element at that point with aValue.
+# It is assumed that the array's values are numeric.
+# This is where the bulk (75%) of the time is spent in this module, so try to
+# make it fast!
+
+sub _replaceNextLargerWith
+{
+	my ( $array, $aValue, $high ) = @_;
+	$high ||= $#$array;
+
+	# off the end?
+	if ( $high == -1 || $aValue > $array->[-1] )
+	{
+		push ( @$array, $aValue );
+		return $high + 1;
+	}
+
+	# binary search for insertion point...
+	my $low = 0;
+	my $index;
+	my $found;
+	while ( $low <= $high )
+	{
+		$index = ( $high + $low ) / 2;
+
+		#		$index = int(( $high + $low ) / 2);		# without 'use integer'
+		$found = $array->[$index];
+
+		if ( $aValue == $found )
+		{
+			return undef;
+		}
+		elsif ( $aValue > $found )
+		{
+			$low = $index + 1;
+		}
+		else
+		{
+			$high = $index - 1;
+		}
+	}
+
+	# now insertion point is in $low.
+	$array->[$low] = $aValue;    # overwrite next larger
+	return $low;
+}
+
+# This method computes the longest common subsequence in $a and $b.
+
+# Result is array or ref, whose contents is such that
+# 	$a->[ $i ] == $b->[ $result[ $i ] ]
+# foreach $i in ( 0 .. $#result ) if $result[ $i ] is defined.
+
+# An additional argument may be passed; this is a hash or key generating
+# function that should return a string that uniquely identifies the given
+# element.  It should be the case that if the key is the same, the elements
+# will compare the same. If this parameter is undef or missing, the key
+# will be the element as a string.
+
+# By default, comparisons will use "eq" and elements will be turned into keys
+# using the default stringizing operator '""'.
+
+# Additional parameters, if any, will be passed to the key generation routine.
+
+sub _longestCommonSubsequence
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $keyGen = shift;    # code ref
+	my $compare;           # code ref
+
+	# set up code refs
+	# Note that these are optimized.
+	if ( !defined($keyGen) )    # optimize for strings
+	{
+		$keyGen = sub { $_[0] };
+		$compare = sub { my ( $a, $b ) = @_; $a eq $b };
+	}
+	else
+	{
+		$compare = sub {
+			my $a = shift;
+			my $b = shift;
+			&$keyGen( $a, @_ ) eq &$keyGen( $b, @_ );
+		};
+	}
+
+	my ( $aStart, $aFinish, $bStart, $bFinish, $matchVector ) =
+	  ( 0, $#$a, 0, $#$b, [] );
+
+	# First we prune off any common elements at the beginning
+	while ( $aStart <= $aFinish
+		and $bStart <= $bFinish
+		and &$compare( $a->[$aStart], $b->[$bStart], @_ ) )
+	{
+		$matchVector->[ $aStart++ ] = $bStart++;
+	}
+
+	# now the end
+	while ( $aStart <= $aFinish
+		and $bStart <= $bFinish
+		and &$compare( $a->[$aFinish], $b->[$bFinish], @_ ) )
+	{
+		$matchVector->[ $aFinish-- ] = $bFinish--;
+	}
+
+	# Now compute the equivalence classes of positions of elements
+	my $bMatches =
+	  _withPositionsOfInInterval( $b, $bStart, $bFinish, $keyGen, @_ );
+	my $thresh = [];
+	my $links  = [];
+
+	my ( $i, $ai, $j, $k );
+	for ( $i = $aStart ; $i <= $aFinish ; $i++ )
+	{
+		$ai = &$keyGen( $a->[$i], @_ );
+		if ( exists( $bMatches->{$ai} ) )
+		{
+			$k = 0;
+			for $j ( @{ $bMatches->{$ai} } )
+			{
+
+				# optimization: most of the time this will be true
+				if ( $k and $thresh->[$k] > $j and $thresh->[ $k - 1 ] < $j )
+				{
+					$thresh->[$k] = $j;
+				}
+				else
+				{
+					$k = _replaceNextLargerWith( $thresh, $j, $k );
+				}
+
+				# oddly, it's faster to always test this (CPU cache?).
+				if ( defined($k) )
+				{
+					$links->[$k] =
+					  [ ( $k ? $links->[ $k - 1 ] : undef ), $i, $j ];
+				}
+			}
+		}
+	}
+
+	if (@$thresh)
+	{
+		for ( my $link = $links->[$#$thresh] ; $link ; $link = $link->[0] )
+		{
+			$matchVector->[ $link->[1] ] = $link->[2];
+		}
+	}
+
+	return wantarray ? @$matchVector : $matchVector;
+}
+
+sub traverse_sequences
+{
+	my $a                 = shift;                                  # array ref
+	my $b                 = shift;                                  # array ref
+	my $callbacks         = shift || {};
+	my $keyGen            = shift;
+	my $matchCallback     = $callbacks->{'MATCH'} || sub { };
+	my $discardACallback  = $callbacks->{'DISCARD_A'} || sub { };
+	my $finishedACallback = $callbacks->{'A_FINISHED'};
+	my $discardBCallback  = $callbacks->{'DISCARD_B'} || sub { };
+	my $finishedBCallback = $callbacks->{'B_FINISHED'};
+	my $matchVector = _longestCommonSubsequence( $a, $b, $keyGen, @_ );
+
+	# Process all the lines in @$matchVector
+	my $lastA = $#$a;
+	my $lastB = $#$b;
+	my $bi    = 0;
+	my $ai;
+
+	for ( $ai = 0 ; $ai <= $#$matchVector ; $ai++ )
+	{
+		my $bLine = $matchVector->[$ai];
+		if ( defined($bLine) )    # matched
+		{
+			&$discardBCallback( $ai, $bi++, @_ ) while $bi < $bLine;
+			&$matchCallback( $ai,    $bi++, @_ );
+		}
+		else
+		{
+			&$discardACallback( $ai, $bi, @_ );
+		}
+	}
+
+	# The last entry (if any) processed was a match.
+	# $ai and $bi point just past the last matching lines in their sequences.
+
+	while ( $ai <= $lastA or $bi <= $lastB )
+	{
+
+		# last A?
+		if ( $ai == $lastA + 1 and $bi <= $lastB )
+		{
+			if ( defined($finishedACallback) )
+			{
+				&$finishedACallback( $lastA, @_ );
+				$finishedACallback = undef;
+			}
+			else
+			{
+				&$discardBCallback( $ai, $bi++, @_ ) while $bi <= $lastB;
+			}
+		}
+
+		# last B?
+		if ( $bi == $lastB + 1 and $ai <= $lastA )
+		{
+			if ( defined($finishedBCallback) )
+			{
+				&$finishedBCallback( $lastB, @_ );
+				$finishedBCallback = undef;
+			}
+			else
+			{
+				&$discardACallback( $ai++, $bi, @_ ) while $ai <= $lastA;
+			}
+		}
+
+		&$discardACallback( $ai++, $bi, @_ ) if $ai <= $lastA;
+		&$discardBCallback( $ai, $bi++, @_ ) if $bi <= $lastB;
+	}
+
+	return 1;
+}
+
+sub traverse_balanced
+{
+	my $a                 = shift;                                  # array ref
+	my $b                 = shift;                                  # array ref
+	my $callbacks         = shift || {};
+	my $keyGen            = shift;
+	my $matchCallback     = $callbacks->{'MATCH'} || sub { };
+	my $discardACallback  = $callbacks->{'DISCARD_A'} || sub { };
+	my $discardBCallback  = $callbacks->{'DISCARD_B'} || sub { };
+	my $changeCallback    = $callbacks->{'CHANGE'};
+	my $matchVector = _longestCommonSubsequence( $a, $b, $keyGen, @_ );
+
+	# Process all the lines in match vector
+	my $lastA = $#$a;
+	my $lastB = $#$b;
+	my $bi    = 0;
+	my $ai    = 0;
+	my $ma    = -1;
+	my $mb;
+
+	while (1)
+	{
+
+		# Find next match indices $ma and $mb
+		do { $ma++ } while ( $ma <= $#$matchVector && !defined $matchVector->[$ma] );
+
+		last if $ma > $#$matchVector;    # end of matchVector?
+		$mb = $matchVector->[$ma];
+
+		# Proceed with discard a/b or change events until
+		# next match
+		while ( $ai < $ma || $bi < $mb )
+		{
+
+			if ( $ai < $ma && $bi < $mb )
+			{
+
+				# Change
+				if ( defined $changeCallback )
+				{
+					&$changeCallback( $ai++, $bi++, @_ );
+				}
+				else
+				{
+					&$discardACallback( $ai++, $bi, @_ );
+					&$discardBCallback( $ai, $bi++, @_ );
+				}
+			}
+			elsif ( $ai < $ma )
+			{
+				&$discardACallback( $ai++, $bi, @_ );
+			}
+			else
+			{
+
+				# $bi < $mb
+				&$discardBCallback( $ai, $bi++, @_ );
+			}
+		}
+
+		# Match
+		&$matchCallback( $ai++, $bi++, @_ );
+	}
+
+	while ( $ai <= $lastA || $bi <= $lastB )
+	{
+		if ( $ai <= $lastA && $bi <= $lastB )
+		{
+
+			# Change
+			if ( defined $changeCallback )
+			{
+				&$changeCallback( $ai++, $bi++, @_ );
+			}
+			else
+			{
+				&$discardACallback( $ai++, $bi, @_ );
+				&$discardBCallback( $ai, $bi++, @_ );
+			}
+		}
+		elsif ( $ai <= $lastA )
+		{
+			&$discardACallback( $ai++, $bi, @_ );
+		}
+		else
+		{
+
+			# $bi <= $lastB
+			&$discardBCallback( $ai, $bi++, @_ );
+		}
+	}
+
+	return 1;
+}
+
+sub LCS
+{
+	my $a = shift;                                           # array ref
+	my $matchVector = _longestCommonSubsequence( $a, @_ );
+	my @retval;
+	my $i;
+	for ( $i = 0 ; $i <= $#$matchVector ; $i++ )
+	{
+		if ( defined( $matchVector->[$i] ) )
+		{
+			push ( @retval, $a->[$i] );
+		}
+	}
+	return wantarray ? @retval : \@retval;
+}
+
+sub diff
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $retval = [];
+	my $hunk   = [];
+	my $discard = sub { push ( @$hunk, [ '-', $_[0], $a->[ $_[0] ] ] ) };
+	my $add = sub { push ( @$hunk, [ '+', $_[1], $b->[ $_[1] ] ] ) };
+	my $match = sub { push ( @$retval, $hunk ) if scalar(@$hunk); $hunk = [] };
+	traverse_sequences( $a, $b,
+		{ MATCH => $match, DISCARD_A => $discard, DISCARD_B => $add }, @_ );
+	&$match();
+	return wantarray ? @$retval : $retval;
+}
+
+sub sdiff
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $retval = [];
+	my $discard = sub { push ( @$retval, [ '-', $a->[ $_[0] ], "" ] ) };
+	my $add = sub { push ( @$retval, [ '+', "", $b->[ $_[1] ] ] ) };
+	my $change = sub {
+		push ( @$retval, [ 'c', $a->[ $_[0] ], $b->[ $_[1] ] ] );
+	};
+	my $match = sub {
+		push ( @$retval, [ 'u', $a->[ $_[0] ], $b->[ $_[1] ] ] );
+	};
+	traverse_balanced(
+		$a,
+		$b,
+		{
+			MATCH     => $match,
+			DISCARD_A => $discard,
+			DISCARD_B => $add,
+			CHANGE    => $change,
+		},
+		@_
+	);
+	return wantarray ? @$retval : $retval;
+}
+
+1;
+}
+import Algorithm::Diff qw(traverse_sequences);
+# End of inserted block for stand-alone version
+
+use Getopt::Long ;
+use strict ;
+use utf8 ;
+
+my ($algodiffversion)=split(/ /,$Algorithm::Diff::VERSION);
+
+
+my ($versionstring)=<<EOF ;
+This is LATEXDIFF 0.5  (Algorithm::Diff $Algorithm::Diff::VERSION)
+  (c) 2004-2007 F J Tilmann
+EOF
+
+# Configuration variables: these have to be visible from the subroutines
+my $MINWORDSBLOCK=3; # minimum number of tokens to form an independent block
+                     # shorter identical blocks will be merged to the previous word
+my $FLOATENV='(?:figure|table|plate)[\w\d*@]*' ;   # Environments in which FL variants of defined commands are used
+my $PICTUREENV='(?:picture|DIFnomarkup)[\w\d*@]*' ;   # Environments in which all change markup is removed
+my $MATHENV='(?:equation|displaymath|DOLLARDOLLAR)' ;           # Environments turning on display math mode (code also knows about \[ and \]
+my $MATHREPL='displaymath';  # Environment introducing deleted maths blocks
+my $MATHARRENV='(?:eqnarray|align|gather|multiline|flalign)[*]?' ;           # Environments turning on eqnarray math mode
+my $MATHARRREPL='eqnarray*';  # Environment introducing deleted maths blocks
+my $ARRENV='(?:array|[pbvBV]matrix)'; # Enviroments making arrays in math mode.  The underlining style does not cope well with those - as a result in-text math environments are surrounded by \mbox{ } if any of these commands is used in an inline math block
+my $COUNTERCMD='(?:footnote|part|section|subsection|subsubsection|paragraph|subparagraph)';  # textcmds which are associated with a counter
+                                        # If any of these commands occur in a deleted block
+                                        # they will be succeeded by an \addtocounter{...}{-1}
+                                        # for the associated counter such that the overall numbers
+                                        # should be the same as in the new file
+
+# Markup strings
+# If at all possible, do not change these as parts of the program
+# depend on the actual name (particularly post-processing)
+# At the very least adapt subroutine postprocess to new tokens.
+my $ADDMARKOPEN='\DIFaddbegin ';   # Token to mark begin of appended text
+my $ADDMARKCLOSE='\DIFaddend ';   # Token to mark end of appended text
+my $ADDOPEN='\DIFadd{';  # To mark begin of added text passage
+my $ADDCLOSE='}';        # To mark end of added text passage
+my $ADDCOMMENT='DIF > ';   # To mark added comment line
+my $DELMARKOPEN='\DIFdelbegin ';   # Token to mark begin of deleted text
+my $DELMARKCLOSE='\DIFdelend ';   # Token to mark end of deleted text
+my $DELOPEN='\DIFdel{';  # To mark begin of deleted text passage
+my $DELCLOSE='}';        # To mark end of deleted text passage
+my $DELCMDOPEN='%DIFDELCMD < ';  # To mark begin of deleted commands (must begin with %, i.e., be a comment
+my $DELCMDCLOSE="%%%\n";    # To mark end of deleted commands (must end with a new line)
+my $AUXCMD='%DIFAUXCMD' ; #  follows auxiliary commands put in by latexdiff to make difference file legal
+                          # auxiliary commands must be on a line of their own
+my $DELCOMMENT='DIF < ';   # To mark deleted comment line
+
+
+# main local variables:
+my @TEXTCMDLIST=();  # array containing patterns of commands with text arguments
+my @TEXTCMDEXCL=();  # array containing patterns of commands without text arguments (if a pattern
+                     # matches both TEXTCMDLIST and TEXTCMDEXCL it is excluded)
+my @CONTEXT1CMDLIST=();  # array containing patterns of commands with text arguments (subset of text commands),
+                         # but which cause confusion if used out of context (e.g. \caption). 
+                         # In deleted passages, the command will be disabled but its argument is marked up
+                         # Otherwise they behave exactly like TEXTCMD's 
+my @CONTEXT1CMDEXCL=();  # exclude list for above, but always empty
+my @CONTEXT2CMDLIST=();  # array containing patterns of commands with text arguments, but which fail cause confusion
+                         # if used out of context (e.g. \title). They and their arguments will be disabled in deleted
+                         # passages
+my @CONTEXT2CMDEXCL=();  # exclude list for above, but always empty
+
+my @SAFECMDLIST=();  # array containing patterns of safe commands (which do not break when in the argument of DIFadd or DIFDEL)
+my @SAFECMDEXCL=();
+
+my ($i,$j,$l);
+my ($old,$new);
+my ($line);
+my ($newpreamble,$oldpreamble);
+my (@newpreamble,@oldpreamble,@diffpreamble,@diffbody);
+my ($latexdiffpreamble);
+my ($oldbody, $newbody, $diffbo);
+my ($oldpost, $newpost);
+my ($diffall);
+# Option names
+my ($type,$subtype,$floattype,$config,$preamblefile,$encoding,
+    $showpreamble,$showsafe,$showtext,$showconfig,$showall,
+    $replacesafe,$appendsafe,$excludesafe,
+    $replacetext,$appendtext,$excludetext,
+    $replacecontext1,$appendcontext1,
+    $replacecontext2,$appendcontext2,
+    $help,$verbose,$version,$ignorewarnings,$allowspaces,$flatten,$debug);
+my (@configlist,
+    @appendsafelist,@excludesafelist,
+    @appendtextlist,@excludetextlist,
+    @appendcontext1list,@appendcontext2list,
+    @packagelist);
+my ($assign,@config);
+# Hash where keys corresponds to the names of  all included packages (including the documentclass as another package
+# the optional arguments to the package are the values of the hash elements
+my ($pkg,%packages);
+# Defaults
+$type='UNDERLINE';
+$subtype='SAFE';
+$floattype='FLOATSAFE';
+
+$verbose=0;
+$debug=1; 
+# define character properties
+sub IsNonAsciiPunct { return <<'END'    # Unicode punctuation but excluding ASCII punctuation
++utf8::IsPunct
+-utf8::IsASCII
+END
+}
+sub IsNonAsciiS { return <<'END'       # Unicode symbol but excluding ASCII
++utf8::IsS
+-utf8::IsASCII
+END
+}
+
+
+
+  my %verbhash;
+
+Getopt::Long::Configure('bundling');
+GetOptions('type|t=s' => \$type, 
+	   'subtype|s=s' => \$subtype, 
+	   'floattype|f=s' => \$floattype, 
+	   'config|c=s' => \@configlist,
+	   'preamble|p=s' => \$preamblefile,
+	   'encoding|e=s' => \$encoding,
+	   'exclude-safecmd|A=s' => \@excludesafelist,
+	   'replace-safecmd=s' => \$replacesafe,
+	   'append-safecmd|a=s' => \@appendsafelist,
+	   'exclude-textcmd|X=s' => \@excludetextlist,
+	   'replace-textcmd=s' => \$replacetext,
+	   'append-textcmd|x=s' => \@appendtextlist,
+	   'replace-context1cmd=s' => \$replacecontext1,
+	   'append-context1cmd=s' => \@appendcontext1list,
+	   'replace-context2cmd=s' => \$replacecontext2,
+	   'append-context2cmd=s' => \@appendcontext2list,
+	   'show-preamble' => \$showpreamble,
+	   'show-safecmd' => \$showsafe,
+	   'show-textcmd' => \$showtext,
+	   'show-config' => \$showconfig,
+	   'show-all' => \$showall,
+           'packages=s' => \@packagelist,
+	   'verbose|V' => \$verbose,
+	   'ignore-warnings' => \$ignorewarnings,
+	   'allow-spaces' => \$allowspaces,
+	   'flatten' => \$flatten,
+	   'version' => \$version,
+	   'help|h|H' => \$help);
+
+if ( $help ) {
+  usage() ;
+}
+
+
+if ( $version ) {
+  die $versionstring ; 
+}
+
+print STDERR $versionstring if $verbose; 
+
+if (defined($showall)){
+  $showpreamble=$showsafe=$showtext=$showconfig=1;
+}
+
+# setting extra preamble commands
+if (defined($preamblefile)) {
+  $latexdiffpreamble=join "\n",(extrapream($preamblefile),"");
+} else {
+  $latexdiffpreamble=join "\n",(extrapream($type,$subtype,$floattype),"");
+}
+
+# setting up @SAFECMDLIST and @SAFECMDEXCL
+if (defined($replacesafe)) {
+  init_regex_arr_ext(\@SAFECMDLIST,$replacesafe);
+} else {
+  init_regex_arr_data(\@SAFECMDLIST, "SAFE COMMANDS");
+}
+foreach $appendsafe ( @appendsafelist ) {
+  init_regex_arr_ext(\@SAFECMDLIST, $appendsafe);
+}
+foreach $excludesafe ( @excludesafelist ) {
+  init_regex_arr_ext(\@SAFECMDEXCL, $excludesafe);
+}
+
+# Special: treat all cite commands as safe except in UNDERLINE and FONTSTRIKE mode
+# (there is a conflict between citation and ulem package, see
+# package documentation)
+if ( uc($type) ne "UNDERLINE" && uc($type) ne "FONTSTRIKE" && uc($type) ne "CULINECHBAR" ) {
+  push (@SAFECMDLIST, qr/^cite.*$/);
+}
+
+# setting up @TEXTCMDLIST and @TEXTCMDEXCL
+if (defined($replacetext)) {
+  init_regex_arr_ext(\@TEXTCMDLIST,$replacetext);
+} else {
+  init_regex_arr_data(\@TEXTCMDLIST, "TEXT COMMANDS");
+}
+foreach $appendtext ( @appendtextlist ) {
+  init_regex_arr_ext(\@TEXTCMDLIST, $appendtext);
+}
+foreach $excludetext ( @excludetextlist ) {
+  init_regex_arr_ext(\@TEXTCMDEXCL, $excludetext);
+}
+
+
+# setting up @CONTEXT1CMDLIST ( @CONTEXT1CMDEXCL exist but is always empty )
+if (defined($replacecontext1)) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST,$replacecontext1);
+} else {
+  init_regex_arr_data(\@CONTEXT1CMDLIST, "CONTEXT1 COMMANDS");
+}
+foreach $appendcontext1 ( @appendcontext1list ) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST, $appendcontext1);
+}
+
+
+# setting up @CONTEXT2CMDLIST ( @CONTEXT2CMDEXCL exist but is always empty )
+if (defined($replacecontext2)) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST,$replacecontext2);
+} else {
+  init_regex_arr_data(\@CONTEXT2CMDLIST, "CONTEXT2 COMMANDS");
+}
+foreach $appendcontext2 ( @appendcontext2list ) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST, $appendcontext2);
+}
+
+
+
+
+# setting configuration variables
+@config=();
+foreach $config ( @configlist ) {
+  if (-f $config ) {
+    open(FILE,$config) or die ("Couldn't open configuration file $config: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@config,$_);
+    }
+    close(FILE);
+  }
+  else {
+#    foreach ( split(",",$config) ) {
+#      push @config,$_;
+#    }
+     push @config,split(",",$config)
+  }
+}
+foreach $assign ( @config ) {
+  $assign=~ m/\s*(\w*)\s*=\s*(\S*)\s*$/ or die "Illegal assignment $assign in configuration list (must be variable=value)";  
+  if ( $1 eq "MINWORDSBLOCK" ) { $MINWORDSBLOCK = $2; }
+  elsif ( $1 eq "FLOATENV" ) { $FLOATENV = $2 ; }
+  elsif ( $1 eq "PICTUREENV" ) { $PICTUREENV = $2 ; }
+  elsif ( $1 eq "MATHENV" ) { $MATHENV = $2 ; }
+  elsif ( $1 eq "MATHREPL" ) { $MATHREPL = $2 ; }
+  elsif ( $1 eq "MATHARRENV" ) { $MATHARRENV = $2 ; }
+  elsif ( $1 eq "MATHARRREPL" ) { $MATHARRREPL = $2 ; }
+  elsif ( $1 eq "ARRENV" ) { $ARRENV = $2 ; }
+  elsif ( $1 eq "COUNTERCMD" ) { $COUNTERCMD = $2 ; }
+  else { die "Unknown variable $1 in assignment.";}
+}
+
+
+foreach $pkg ( @packagelist ) {
+  map { $packages{$_}="" } split(/,/,$pkg) ;
+}
+
+if ($showpreamble) {
+  print "\nPreamble commands:\n";
+  print $latexdiffpreamble ;
+}
+
+if ($showsafe) {
+  print "\nCommands safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE (unless excluded):\n";
+  print_regex_arr(@SAFECMDLIST);
+  print "\nCommands not safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE :\n";
+  print_regex_arr(@SAFECMDEXCL);
+}
+
+if ($showtext) {
+  print "\nCommands with last argument textual (unless excluded) and safe in every context:\n";
+  print_regex_arr(@TEXTCMDLIST);
+  print "\nContext1 commands (last argument textual, command will be disabled in deleted passages, last argument will be shown as plain text):\n";
+  print_regex_arr(@CONTEXT1CMDLIST);
+  print "\nContext2 commands (last argument textual, command ant its argument will be disabled in deleted passages):\n";
+  print_regex_arr(@CONTEXT2CMDLIST);  
+  print "\nExclude list of Commands with last argument not textual (overrides patterns above):\n";
+  print_regex_arr(@TEXTCMDEXCL);
+}
+
+if ($showconfig) {
+  print "Configuration variables:\n";
+  print "MINWORDSBLOCK=$MINWORDSBLOCK\n";
+  print "FLOATENV=$FLOATENV\n";
+  print "PICTUREENV=$PICTUREENV\n";
+  print "MATHENV=$MATHENV\n";
+  print "MATHREPL=$MATHREPL\n";
+  print "MATHARRENV=$MATHARRENV\n";
+  print "MATHARRREPL=$MATHARRREPL\n";
+  print "ARRENV=$ARRENV\n";
+  print "COUNTERCMD=$COUNTERCMD\n";
+}
+if ($showconfig || $showtext || $showsafe || $showpreamble) {
+  exit 0; }
+if ( @ARGV != 2 ) { 
+  print STDERR "2 and only 2 non-option arguments required.  Write latexdiff -h to get help\n";
+  exit(2);
+}
+
+# Are extra spaces between command arguments permissible?
+my $extraspace;
+if ($allowspaces) {
+  $extraspace='\s*'; 
+} else {
+  $extraspace='';
+}
+
+# append context lists to text lists (as text property is implied)
+push @TEXTCMDLIST, @CONTEXT1CMDLIST;
+push @TEXTCMDLIST, @CONTEXT2CMDLIST;
+
+
+# Patterns. These are used by some of the subroutines, too
+# I can only define them down here because value of extraspace depends on an option
+  my $pat0 = '(?:[^{}]|\\\{|\\\})*';
+  my $pat1 = '(?:[^{}]|\\\{|\\\}|\{'.$pat0.'\})*';
+  my $pat2 = '(?:[^{}]|\\\{|\\\}|\{'.$pat1.'\})*'; # 
+  my $pat3 = '(?:[^{}]|\\\{|\\\}|\{'.$pat2.'\})*';
+  my $pat4 = '(?:[^{}]|\\\{|\\\}|\{'.$pat3.'\})*';
+  my $brat0 = '(?:[^\[\]]|\\\[|\\\])*'; 
+
+  my $quotemarks = '(?:\'\')|(?:\`\`)';
+  my $punct='[0.,\/\'\`:;\"\?\(\)\[\]!~\p{IsNonAsciiPunct}\p{IsNonAsciiS}]';
+  my $number='-?\d*\.\d*';
+  my $mathpunct='[+=<>\-\|]';
+  my $and = '&';
+  my $coords= '[\-.,\s\d]*';
+# word: sequence of letters or accents followed by letter
+  my $word='(?:[-\w\d*]|\\\\[\"\'\`~^][A-Za-z\*])+';
+  my $cmdleftright='\\\\(?:left|right)\s*(?:[()\[\]|]|\\\\(?:[|{}]|\w+))';
+
+  my $cmdoptseq='\\\\[\w\d\*]+'.$extraspace.'(?:(?:\['.$brat0.'\]|\{'. $pat4 . '\}|\(' . $coords .'\))'.$extraspace.')*';
+  my $oneletcmd='\\\\.(?:\['.$brat0.'\]|\{'. $pat4 . '\})*';
+  my $math='\$(?:[^$]|\\\$)*?\$|\\\\[(].*?\\\\[)]';
+#  my $math='\$(?:[^$]|\\\$)*\$';
+  my $comment='%.*?\n';
+  my $pat=qr/(?:\A\s*)?(?:${and}|${quotemarks}|${number}|${word}|$cmdleftright|${cmdoptseq}|${math}|${oneletcmd}|${comment}|${punct}|${mathpunct}|\{|\})\s*/ ;
+
+
+
+# now we are done setting up and can start working   
+my ($oldfile, $newfile) = @ARGV;
+
+$encoding=guess_encoding($newfile) unless defined($encoding);
+
+$encoding = "utf8" if $encoding =~ m/^utf8/i ;
+if (lc($encoding) eq "utf8" ) {
+  binmode(STDOUT, ":utf8");
+  binmode(STDERR, ":utf8");
+}
+
+$old=read_file_with_encoding($oldfile,$encoding);
+$new=read_file_with_encoding($newfile,$encoding);
+
+
+
+
+# reset time
+exetime(1);
+($oldpreamble,$oldbody,$oldpost)=splitdoc($old,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+($newpreamble,$newbody,$newpost)=splitdoc($new,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+if ($flatten) {
+  $oldbody=flatten($oldbody,$oldpreamble,$oldfile,$encoding);
+  $newbody=flatten($newbody,$newpreamble,$newfile,$encoding);
+}
+
+if ( length $oldpreamble && length $newpreamble ) {
+  @oldpreamble = split /\n/, $oldpreamble;
+  @newpreamble = split /\n/, $newpreamble;
+  
+  %packages=list_packages(@newpreamble) unless %packages;
+  if (defined $packages{"hyperref"} ) {
+    print STDERR "hyperref package detected.\n" if $verbose ;
+    $latexdiffpreamble =~ s/\{\\DIFadd\}/{\\DIFaddtex}/g;
+    $latexdiffpreamble =~ s/\{\\DIFdel\}/{\\DIFdeltex}/g;
+    $latexdiffpreamble .= join "\n",(extrapream("HYPERREF"),"");
+  }
+  # insert dummy first line such that line count begins with line 1 (rather than perl's line 0) - just so that line numbers inserted by linediff are correct
+  unshift @newpreamble,'';
+  unshift @oldpreamble,'';
+  print STDERR "Differencing preamble.\n" if $verbose;
+  @diffpreamble = linediff(\@oldpreamble, \@newpreamble);
+  # remove dummy line again
+  shift @diffpreamble; 
+  push @diffpreamble,$latexdiffpreamble;
+  push @diffpreamble,'\begin{document}';
+}
+elsif ( !length $oldpreamble && !length $newpreamble ) {
+  @diffpreamble=();
+} else {
+  print STDERR "Either both texts must have preamble or neither text must have the preamble.\n";
+  exit(2);
+}
+
+if (defined $packages{"amsmath"} ) {
+  print STDERR "amsmath package detected.\n" if $verbose ;
+  $MATHARRREPL='align*';
+}
+
+print STDERR "Preprocessing body.  " if $verbose;
+my ($oldleadin,$newleadin)=preprocess($oldbody,$newbody);
+
+
+# run difference algorithm
+@diffbody=bodydiff($oldbody, $newbody);
+$diffbo=join("",@diffbody);
+print STDERR "(",exetime()," s)\n","Postprocessing body. \n " if $verbose;
+postprocess($diffbo);
+$diffall =join("\n",@diffpreamble) ;
+$diffall .= "$newleadin$diffbo" ;
+$diffall .= "\\end{document}$newpost" if length $newpreamble ;
+if ( lc($encoding) ne "utf8" && lc($encoding) ne "ascii" ) {
+  print STDERR "Encoding output file to $encoding\n" if $verbose;
+  $diffall=Encode::encode($encoding,$diffall);
+  binmode STDOUT;
+}
+print $diffall;
+
+
+print STDERR "(",exetime()," s)\n","Done.\n" if $verbose;
+
+
+
+## guess_encoding(filename)
+## reads the first 20 lines of filename and looks for call of inputenc package
+## if found, return the option of this package (encoding), otherwise return ascii
+sub guess_encoding {
+  my ($filename)=@_;
+  my ($i,$enc);
+  open (FH, $filename) or die("Couldn't open $filename: $!");
+  $i=0;
+  while (<FH>) {
+    next if /^\s*%/;    # skip comment lines
+    if (m/\\usepackage\[(\w*?)\]\{inputenc\}/) {
+      close(FH);
+      return($1);
+    }
+    last if (++$i > 20 ); # scan at most 20 non-comment lines
+  }
+  close(FH);
+  return("ascii");
+}
+
+
+sub read_file_with_encoding {
+  my ($output);
+  my ($filename, $encoding) = @_;
+
+  if (lc($encoding) eq "utf8" ) {
+    open (FILE, "<:utf8",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } elsif ( lc($encoding) eq "ascii") {
+    open (FILE, $filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } else {
+    require Encode;
+    open (FILE, "<",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+    print STDERR "Converting $filename from $encoding to utf8\n" if $verbose;
+    $output=Encode::decode($encoding,$output);
+  }
+  close FILE;
+  return $output;
+}
+
+# %packages=list_packages(@preamble)
+# scans the arguments for \documentclass and \usepackage statements and constructs a hash
+# whose keys are the included packages, and whose values are the associated optional arguments
+sub list_packages {
+  my (@preamble)=@_;
+  my %packages=();
+  foreach $line ( @preamble ) {
+    # get rid of comments
+    $line=~s/(?<!\\)%.*$// ;
+    if ( $line =~ m/\\(?:documentclass|usepackage)(?:\[(.+?)\])?\{(.*?)\}/ ) {
+#      print STDERR "Found something: |$line|\n";
+      if (defined($1)) {
+	$packages{$2}=$1;
+      } else {
+	$packages{$2}="";
+      }
+    }
+  }
+  return (%packages);
+}
+
+# flatten($text,$preamble,$filename,$encoding)
+# expands \input and \include commands within text
+# premable is scanned for includeonly commands
+# encoding is the encoding
+sub flatten {
+  my ($text,$preamble,$filename,$encoding)=@_;
+  my ($includeonly,$dirname,$fname,$newpage,$replacement);
+  require File::Basename ; 
+  require File::Spec ; 
+  $dirname = File::Basename::dirname($filename);
+
+  if ( ($includeonly) = ($preamble =~ m/\\includeonly{(.*?)}/ ) ) {
+    $includeonly =~ s/,/|/g;
+  } else {
+    $includeonly = '.*?';
+  }
+
+  print STDERR "DEBUG: includeonly $includeonly\n";
+
+  $text=~s/\\input{(.*?)}|\\include{(${includeonly}(?:\.tex)?)}/{ 
+	    $fname = $1 if defined($1)  ;
+	    $fname = $2 if defined($2) ;       
+            #      # add tex extension unless there is a three letter extension already 
+            $fname .= ".tex" unless $fname =~ m|\.\w{3}|;
+            print STDERR "Include file $fname\n" if $verbose;
+            print STDERR "DEBUG looking for file ",File::Spec->catfile($dirname,$fname), "\n";
+            # content of file becomes replacement value, add \newpage if the command was include
+            $replacement=read_file_with_encoding(File::Spec->catfile($dirname,$fname), $encoding) or die
+                "Couldn't find file ",File::Spec->catfile($dirname,$fname),": $!";
+	    $newpage=(defined($2)? " \\newpage " : "") ;
+	    "$newpage$replacement$newpage";
+          }/exg;
+
+  return($text);
+}
+
+
+# print_regex_arr(@arr)
+# prints regex array without x-ism expansion put in by pearl to stdout
+sub print_regex_arr {
+  my $dumstring;
+  $dumstring = join(" ",@_);     # PERL generates string (?-xism:^ref$) for quoted refex ^ref$
+  $dumstring =~ s/\(\?-xism:\^(.*?)\$\)/$1/g;   # remove string and ^,$ marks before output
+  print $dumstring,"\n";
+}
+
+
+# @lines=extrapream($type)
+# reads line from appendix (end of file after __END__ token)
+sub extrapream {
+  my $type;
+  my @retval=("%DIF PREAMBLE EXTENSION ADDED BY LATEXDIFF") ;
+  my ($copy);
+
+  while (@_) {
+    $copy=0;
+    $type=shift ;
+    if ( -f $type ) {
+      open (FILE,$type) or die "Cannot open preamble file $type: $!";
+      print STDERR "Reading preamble file $type\n" if $verbose ;
+      while (<FILE>) {
+	chomp ;
+	if ( $_ =~ m/%DIF PREAMBLE/ ) {
+	  push (@retval,"$_"); 
+	} else {
+	  push (@retval,"$_ %DIF PREAMBLE"); 
+	}
+      }
+    } 
+    else {    # not (-f $type)
+      $type=uc($type);   # upcase argument
+      print STDERR "Preamble Internal Type $type\n" if $verbose;
+      while (<DATA>) {
+	if ( m/^%DIF $type/ ) {
+	  $copy=1; }
+	elsif ( m/^%DIF END $type/ ) {
+	  last; }
+	chomp;
+	push (@retval,"$_ %DIF PREAMBLE") if $copy;
+      }
+      if ( $copy == 0 ) {
+	print STDERR "\nPreamble style $type not implemented.\n";
+        print STDERR "Write latexdiff -h to get help with available styles\n";
+        exit(2);
+      }
+      seek DATA,0,0;    # rewind DATA handle to file begin
+    }
+  }
+  push (@retval,"%DIF END PREAMBLE EXTENSION ADDED BY LATEXDIFF")  ;
+  return @retval;
+}
+
+
+# ($part1,$part2,$part3)=splitdoc($text,$word1,$word2)
+# splits $text into 3 parts at $word1 and $word2.
+# if neither $word1 nor $word2 exist, $part1 and $part3 are empty, $part2 is $text
+# If only $word1 or $word2 exist but not the other, output an error message.
+
+# NB this version avoids $` and $' for performance reason although it only makes a tiny difference
+# (in one test gain a tenth of a second for a 30s run)
+sub splitdoc {
+  my ($text,$word1,$word2)=@_;
+  my ($part1,$part2,$part3)=("","","");
+  my ($rest,$pos);
+
+  if ( $text =~ m/(^[^%]*)($word1)/mg ) {
+    $pos=pos $text;
+    $part1=substr($text,0,$pos-length($2));
+    $rest=substr($text,$pos);
+    if ( $rest =~ m/(^[^%]*)($word2)/mg ) {
+      $pos=pos $rest;
+      $part2=substr($rest,0,$pos-length($2));
+      $part3=substr($rest,$pos);
+    } 
+    else {
+      die "$word1 and $word2 not in the correct order or not present as a pair." ;
+    }
+  } else {
+    $part2=$text;
+    die "$word2 present but not $word1." if ( $text =~ m/(^[^%]*)$word2/ms );
+  }
+  return ($part1,$part2,$part3);
+}
+
+
+
+
+
+# bodydiff($old,$new)
+sub bodydiff {
+  my ($oldwords, $newwords) = @_;
+  my @retwords;
+
+  print STDERR "(",exetime()," s)\n","Splitting into latex tokens \n" if $verbose;
+  print STDERR "Parsing $oldfile \n" if $verbose;
+  my @oldwords = splitlatex($oldwords);
+  print STDERR "Parsing $newfile \n" if $verbose;
+  my @newwords = splitlatex($newwords);
+  my $token;
+
+  print STDERR "(",exetime()," s)\n","Pass 1: Expanding text commands and merging isolated identities with changed blocks  " if $verbose;
+  pass1(\@oldwords, \@newwords);
+
+
+  print STDERR "(",exetime()," s)\n","Pass 2: inserting DIF tokens and mark up.  " if $verbose;
+
+  @retwords=pass2(\@oldwords, \@newwords);
+
+  return(@retwords);
+}
+
+
+
+
+# @words=splitlatex($string)
+# split string according to latex rules
+# Each element of words is either
+# a word (including trailing spaces and punctuation)
+# a latex command
+sub splitlatex {
+  my ($string) = @_ ;
+  my @retval=($string =~ m/$pat/osg);  
+
+  if (length($string) != length(join("",@retval))) {
+    print STDERR "\nWARNING: Inconsistency in length of input string and parsed string:\n     This often indicates faulty or non-standard latex code.\n     In many cases you can ignore this and the following warning messages.\n Note that character numbers in the following are counted beginning after \\begin{document} and are only approximate." unless $ignorewarnings;
+    print STDERR "DEBUG Original length ",length($string),"  Parsed length ",length(join("",@retval)),"\n" if $debug;
+    print STDERR "DEBUG Input string:  |$string|\n" if (length($string)<500) && $debug;
+    print STDERR "DEBUG Token parsing: |",join("+",@retval),"|\n" if (length($string)<500) && $debug ;
+    @retval=();
+    # slow way only do this if other m//sg method fails
+    my $last = 0;
+    while ( $string =~ m/$pat/osg ) {
+      my $match=$&;
+      if ($last + length $& != pos $string  ) {
+	my $pos=pos($string);
+	my $offset=30<$last ? 30 : $last;
+	my $dum=substr($string,$last-$offset,$pos-$last+2*$offset);
+	my $dum1=$dum;
+	my $cnt=$#retval;
+	my $i;
+	$dum1 =~ s/\n/ /g;
+	unless ($ignorewarnings) {
+	  print STDERR "\n$dum1\n";
+	  print STDERR " " x 30,"^" x ($pos-$last)," " x 30,"\n";
+	  print STDERR "Missing characters near word " . (scalar @retval) . " character index: " . $last . "-" .  pos($string) . " Length: " . length($match) . " Match: |$match| (expected match marked above).\n";
+	}
+	  # put in missing characters `by hand'
+	push (@retval, substr($dum,$offset,$pos-$last-length($match)));
+#       Note: there seems to be a bug in substr with utf8 that made the following line output substr which were too long,
+#             using dum instead appears to work
+#	push (@retval, substr($string,$last, pos($string)-$last-length($match)));
+      }
+      push (@retval, $match);
+      $last=pos $string;
+    }
+
+  }
+  return @retval;
+}
+
+
+# pass1( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.
+# Where an common-subsequence block is flanked by deleted or appended blocks, 
+# and is shorter than $MINWORDSBLOCK words it is appended
+# to the last deleted or appended word.  If the block contains tokens other than words 
+# or punctuation it is not merged.
+# Deleted or appended block consisting of words and safe commands only are
+# also merged, to prevent break-up in pass2 (after previous isolated words have been removed)
+# If there are commands with textual arguments (e.g. \caption) both in corresponding 
+# appended and deleted blocks split them such that the command and opening bracket 
+# are one token, then the rest is split up following standard rules, and the closing 
+# bracket is a separate token, ie. turn
+# "\caption{This is a textual argument}" into 
+# ("\caption{","This ","is ","a ","textual ","argument","}")
+# No return value.  Destructively changes sequences
+sub pass1 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $len1 = scalar @$seq1;
+  my $len2 = scalar @$seq2;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;   #'
+
+  my ($last1,$last2)=(-1,-1) ;
+  my $cnt=0;
+  my $block=[];
+  my $addblock=[];
+  my $delblock=[];
+  my $todo=[];
+  my $instruction=[];
+  my $i;
+  my (@delmid,@addmid,@dummy);
+
+  my ($addcmds,$delcmds,$matchindex);
+  my ($addtextblocks,$deltextblocks);
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $adddiscard = sub {
+                      if ($cnt > 0 ) {
+			$matblkcnt++;
+			# just after an unchanged block 
+#			print STDERR "Unchanged block $cnt, $last1,$last2 \n";
+                        if ($cnt < $MINWORDSBLOCK 
+			    && $cnt==scalar (
+				     grep { /^$wpat/ || ( /^\\([\w\d\*]+)((?:\[$brat0\]|\{$pat4\})*)/o 
+							   && iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+							   && scalar(@dummy=split(" ",$2))<3 ) }
+					     @$block) )  {
+			  # merge identical blocks shorter than $MINWORDSBLOCK 
+			  # and only containing ordinary words
+			  # with preceding different word
+			  # We cannot carry out this merging immediately as this
+			  # would change the index numbers of seq1 and seq2 and confuse
+			  # the algorithm, instead we store in @$todo where we have to merge
+                          push(@$todo, [ $last1,$last2,$cnt,@$block ]);
+			}
+			$block = []; 
+			$cnt=0; $last1=-1; $last2=-1;
+		      }
+		    };
+  my $discard=sub { $deltokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$delblock,[ $seq1->[$_[0]],$_[0] ]);
+		    $last1=$_[0] };		      
+
+  my $add =   sub { $addtokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$addblock,[ $seq2->[$_[1]],$_[1] ]);
+		    $last2=$_[1] };		      
+
+  my $match = sub { $mattokcnt++;
+                    if ($cnt==0) {   # first word of matching sequence after changed sequence or at beginning of word sequence
+		      $deltextblocks = extracttextblocks($delblock); 
+		      $delblkcnt++ if scalar @$delblock;
+		      $addtextblocks = extracttextblocks($addblock);
+		      $addblkcnt++ if scalar @$addblock;
+
+		      $delcmds = extractcommands($delblock);
+      		      $addcmds = extractcommands($addblock);
+		      # keygen(third argument of _longestCommonSubsequence) implies to sort on command (0th elements of $addcmd elements)
+		      # the calling format for longestCommonSubsequence has changed between versions of
+		      # Algorithm::Diff so we need to check which one we are using
+		      if ( $algodiffversion  > 1.15 ) {
+			### Algorithm::Diff 1.19
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, 0, sub { $_[0]->[0] } );
+		      } else {
+			### Algorithm::Diff 1.15	
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, sub { $_[0]->[0] } );
+		      }
+
+		      for ($i=0 ; $i<=$#$matchindex ; $i++) {
+			if (defined($matchindex->[$i])){
+			  $j=$matchindex->[$i];
+			  @delmid=splitlatex($delcmds->[$i][3]);
+			  @addmid=splitlatex($addcmds->[$j][3]);
+			  while (scalar(@$deltextblocks)  && $deltextblocks->[0][0]<$delcmds->[$i][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$deltextblocks) };
+			    push(@$todo, [$index,-1,$cnt,@$block]);
+			  }
+			  push(@$todo, [ $delcmds->[$i][1],-1,-1,$delcmds->[$i][2],@delmid,$delcmds->[$i][4]]);
+
+			  while (scalar(@$addtextblocks) && $addtextblocks->[0][0]<$addcmds->[$j][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			    push(@$todo, [-1,$index,$cnt,@$block]);
+			  }
+			  push(@$todo, [ -1,$addcmds->[$j][1],-1,$addcmds->[$j][2],@addmid,$addcmds->[$j][4]]);
+			}
+		      }
+		      # mop up remaining textblocks
+		      while (scalar(@$deltextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$deltextblocks) } ;
+			push(@$todo, [$index,-1,$cnt,@$block]);
+		      }
+		      while (scalar(@$addtextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			push(@$todo, [-1,$index,$cnt,@$block]);
+		      }
+		      
+		      $addblock=[];
+		      $delblock=[];
+		    }
+		    push(@$block,$seq2->[$_[1]]);  
+		    $cnt++  };
+
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+
+
+  # now carry out the merging/splitting.  Refer to elements relative from 
+  # the end (with negative indices) as these offsets don't change before the instruction is executed
+  # cnt>0: merged small unchanged groups with previous changed blocks
+  # cnt==-1: split textual commands into components
+  foreach $instruction ( @$todo) {
+    ($last1,$last2,$cnt,@$block)=@$instruction ;
+    if ($cnt>=0) {
+      splice(@$seq1,$last1-$len1,1+$cnt,join("",$seq1->[$last1-$len1],@$block)) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1+$cnt,join("",$seq2->[$last2-$len2],@$block)) if $last2>=0;
+    } else {
+      splice(@$seq1,$last1-$len1,1,@$block) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1,@$block) if $last2>=0;
+    }
+  }
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens in $matblkcnt blocks.\n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+}
+
+
+# extracttextblocks(\@blockindex)
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [[ $index, $textblock, $cnt ], ..
+# where $index index of block to be merged
+#       $textblock contains all the words to be merged with the word at $index (but does not contain this word)
+#       $cnt   is length of block
+#
+# requires: iscmd
+#
+sub extracttextblocks { 
+  my $block=shift;
+  my ($i,$token,$index);
+  my $textblock=[];
+  my $last=-1;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;  #'
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # store pure text blocks
+    if ($token =~ /$wpat/ ||  ( $token =~/^\\([\w\d\*]+)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*)/o 
+				&& iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+				&& !iscmd($1,\@TEXTCMDLIST,\@TEXTCMDEXCL))) {
+      # we have text or a command which can be treated as text
+      if ($last<0) {
+	# new pure-text block
+	$last=$index;
+      } else {
+	# add to pure-text block
+	push(@$textblock, $token); 
+      }
+    } else {
+      # it is not text
+      if (scalar(@$textblock)) {
+	push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+      }
+      $textblock=[];
+      $last=-1;
+    }
+  }
+  # finish processing a possibly unfinished block before returning
+  if (scalar(@$textblock)) {
+    push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+  }
+  return($retval)
+}
+
+
+
+# extractcommands( \@blockindex )
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [ [ "\cmd1", index, "\cmd1[optarg]{arg1}{", "arg2" ,"} " ],.. 
+# where index is just taken from input array 
+# command must have a textual argument as last argument 
+# 
+# requires: iscmd 
+# 
+sub extractcommands { 
+  my $block=shift;
+  my ($i,$token,$index,$cmd,$open,$mid,$closing);
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # check if token is an alphanumeric command sequence with at least one non-optional argument
+    # \cmd[...]{...}{last argument}  
+    # Capturing in the following results in these associations
+    # $1: \cmd[...]{...}{
+    # $2: \cmd
+    # $3: last argument
+    # $4: }  + trailing spaces
+    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	 && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL) ) {
+      #      push(@$retval,[ $2,$index,$1,$3,$4 ]);
+      ($cmd,$open,$mid,$closing) = ($2,$1,$3,$4) ;
+      $closing =~ s/\}/\\RIGHTBRACE/ ;
+      push(@$retval,[ $cmd,$index,$open,$mid,$closing ]);
+    }
+  }
+  return $retval;
+}
+
+# iscmd($cmd,\@regexarray,\@regexexcl) checks
+# return 1 if $cmd matches any of the patterns in the 
+# array $@regexarray, and none of the patterns in \@regexexcl, otherwise return 0
+sub iscmd {
+  my ($cmd,$regexar,$regexexcl)=@_;
+  my ($ret)=0;
+  foreach $pat ( @$regexar ) {
+    if ( $cmd =~ m/^${pat}$/ ) {
+      $ret=1 ; 
+      last;
+    }
+  }
+  return 0 unless $ret;
+  foreach $pat ( @$regexexcl ) {
+    return 0 if ( $cmd =~ m/^${pat}$/ );
+  }
+  return 1;
+}
+
+
+# pass2( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.  
+# Mark begin and end of deleted and appended sequences with tags $DELOPEN and $DELCLOSE
+# and $ADDOPEN and $ADDCLOSE, respectively, however exclude { } & and all comands, unless
+# they match an element of the whitelist (SAFECMD)
+# For words in TEXTCMD but not in SAFECMD, enclose interior with $ADDOPEN and $ADDCLOSE brackets
+# Deleted comment lines are marked with %DIF < 
+# Added comment lines are marked with %DIF > 
+sub pass2 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $retval = [];
+  my $delhunk   = [];
+  my $addhunk   = [];
+
+  my $discard = sub { $deltokcnt++;
+                      push ( @$delhunk, $seq1->[$_[0]]) };
+
+  my $add = sub { $addtokcnt++;
+                  push ( @$addhunk, $seq2->[$_[1]]) };
+
+  my $match = sub { $mattokcnt++;
+		    if ( scalar @$delhunk ) {
+                      $delblkcnt++;
+		      # mark up changes, but comment out commands
+                      push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk);
+		      $delhunk = [];
+		    }
+                    if ( scalar @$addhunk ) {
+                      $addblkcnt++;
+                      # we mark up changes, but simply quote commands
+                      push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk);
+		      $addhunk = [];
+		    }
+		    push(@$retval,$seq2->[$_[1]]) };
+ 
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  # clear up unprocessed hunks
+  push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk) if scalar @$delhunk;
+  push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk) if scalar @$addhunk;
+
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens. \n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+
+  return(@$retval);
+}
+
+# marktags($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,\@block)
+# returns ($openmark,$open,$block,$close,$closemark) if @block only contains no commands (except white-listed ones),
+# braces, ampersands, or comments
+# mark comments with $comment
+# exclude all other exceptions from scope of open, close like this
+# ($openmark, $open,...,$close, $opencomd,command, command,$closecmd, $open, ..., $close, $closemark)
+# If $opencmd begins with "%" marktags assumes it is operating on a deleted block, otherwise on an added block
+sub marktags {
+  my ($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,$block)=@_;
+  my $word;
+  my (@argtext);
+  my $retval=[];
+  my $noncomment=0;
+  my $cmd=-1;    # -1 at beginning 0: last token written is a ordinary word 
+                 # 1: last token written is a command
+                # for keeping track whether we are just in a command sequence or in a word sequence
+  my $cmdcomment= ($opencmd =~ m/^%/);  # Flag to indicate whether opencmd is a comment (i.e. if we intend to simply comment out changed commands)
+  my ($command,$commandword,$closingbracket) ; # temporary variables needed below to remember sub-pattern matches
+
+# split this block to flatten out sequences joined in pass1
+  @$block=splitlatex(join "",@$block);
+  foreach (@$block) {
+    $word=$_; 
+    if ( $word =~ s/^%/%$comment/ ) {
+      # a comment
+      if ($cmd==1) {
+	push (@$retval,$closecmd) ;
+	$cmd=-1;
+      }
+      push (@$retval,$word); 
+      next;
+    }
+    if (! $noncomment) {
+      push (@$retval,$openmark); 
+      $noncomment=1;
+    }
+    # negative lookahead pattern (?!) in second clause is put in to avoid mathcing \( .. \) patterns
+    if ( $word =~ /^[&{}\[\]]/ || ( $word =~ /^\\(?!\()([\w*@]*)/ && !iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL)) ) {
+      # word is a command or other significant token (not in SAFECMDLIST)
+	## same conditions as in subroutine extractcommand:
+	# check if token is an alphanumeric command sequence with at least one non-optional argument
+	# \cmd[...]{...}{last argument}  
+	# Capturing in the following results in these associations
+	# $1: \cmd[...]{...}{
+	# $2: \cmd
+	# $3: last argument
+	# $4: }  + trailing spaces
+	### pre-0.3    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:\[$brat0\]|\{$pat4\})*\{)($pat4)(\}\s*)$/so )
+      if ( ( $word =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	   && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL)  && ( !$cmdcomment || !iscmd($2,\@CONTEXT2CMDLIST, \@CONTEXT2CMDEXCL) )  ) {	 
+	# word is a text command - we mark up the interior of the word. But if we are in a deleted block ($cmdcomment=1) and
+        # $2 (the command) is in context2, just treat it as an ordinary command (i.e. comment it open with $opencmd)
+        # Because we do not want to disable this command
+	# here we do not use $opencmd and $closecmd($opencmd is empty) 
+	if ($cmd==1) {
+	  push (@$retval,$closecmd) ;
+	} elsif ($cmd==0) { 
+	  push (@$retval,$close) ;
+	}
+        $command=$1; $commandword=$2; $closingbracket=$4;
+	@argtext=splitlatex($3);   # split textual argument into tokens
+	# and mark it up (but we do not need openmark and closemark)
+        # insert command with initial arguments, marked-up final argument, and closing bracket
+	if ( $cmdcomment && iscmd($commandword,\@CONTEXT1CMDLIST, \@CONTEXT1CMDEXCL) ) {
+	  # context1cmd in a deleted environment; delete command itself but keep last argument, marked up
+	  push (@$retval,$opencmd);
+	  $command =~ s/\n/\n${opencmd}/sg ; # repeat opencmd at the beginning of each line
+	  # argument, note that the additional comment character is included
+          # to suppress linebreak after opening parentheses, which is important
+          # for latexrevise
+          push (@$retval,$command,"%\n{$AUXCMD\n",marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);
+	} else {
+	  # normal textcmd or context1cmd in an added block
+	  push (@$retval,$command,marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);  
+	}
+	push (@$retval,$AUXCMD,"\n") if $cmdcomment ;
+	$cmd=-1 ;
+      } else {
+	# ordinary command
+	push (@$retval,$opencmd) if $cmd==-1 ;
+	push (@$retval,$close,$opencmd) if $cmd==0 ;
+	$word =~ s/\n/\n${opencmd}/sg if $cmdcomment ;   # if opencmd is a comment, repeat this at the beginning of every line
+	push (@$retval,$word);
+	$cmd=1;
+      }
+    } else {
+      # just an ordinary word or word in SAFECMD
+      push (@$retval,$open) if $cmd==-1 ;
+      push (@$retval,$closecmd,$open) if $cmd==1 ;
+      push (@$retval,$word);
+      $cmd=0;
+    }
+  }
+  push (@$retval,$close) if $cmd==0;
+  push (@$retval,$closecmd) if $cmd==1;
+
+  push (@$retval,$closemark) if ($noncomment);
+  return @$retval;
+}
+
+# preprocess($string, ..)
+# carry out the following pre-processing steps for all arguments:
+# 1. Remove leading white-space
+# 2. mark all first empty line (in block of several) with \PAR tokens
+# 3. Convert all '\%' into '\PERCENTAGE ' to make parsing regular expressions easier
+# 4. Convert all \verb|some verbatim text| commands (where | can be an arbitrary character)
+#    into \verb{hash}
+# 5. Convert \begin{verbatim} some verbatim text \end{verbatim} into \verbatim{hash}
+# 6. Convert _n into \SUBSCRIPTNB{n} and _{nnn} into \SUBSCRIPT{nn}
+# 7. Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+# 8. a. Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+#    b. Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+
+# 9. Add final token STOP to the very end.  This is put in because the algorithm works better if the last token is identical.  This is removed again in postprocessing.
+#
+# NB: step 6 and 7 is likely to  convert some "_" inappropriately, e.g. in file
+#     names or labels but it does not matter because they are converted back in the postprocessing step
+# Returns: leading white space removed in step 1
+sub preprocess {
+  my @leadin=() ;
+  for (@_) { 
+    s/^(\s*)//s;
+    push(@leadin,$1);
+    s/\n(\s*?)\n((?:\s*\n)*)/\n$1\\PAR\n$2/g ;
+    s/(?<!\\)\\%/\\PERCENTAGE /g ;  # (?<! is negative lookbehind assertion to prevent \\% from being converted
+    s/(\\verb\*?)(\S)(.*?)\2/"${1}{". tohash(\%verbhash,"${2}${3}${2}") ."}"/esg;
+    s/\\begin\{(verbatim\*?)\}(.*?)\\end\{\1\}/"\\${1}{". tohash(\%verbhash,"${2}") . "}"/esg;
+    # Convert _n or _\cmd into \SUBSCRIPTNB{n} or \SUBSCRIPTNB{\cmd} and _{nnn} into \SUBSCRIPT{nn}
+    s/_([^{\\]|\\\w+)/\\SUBSCRIPTNB{$1}/g ;
+    s/_{($pat4)}/\\SUBSCRIPT{$1}/g ;
+    # Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+    s/\^([^{\\]|\\\w+)/\\SUPERSCRIPTNB{$1}/g ;
+    s/\^{($pat4)}/\\SUPERSCRIPT{$1}/g ;
+    # Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+    s/\$\$(.*?)\$\$/\\begin{DOLLARDOLLAR}$1\\end{DOLLARDOLLAR}/sg;
+    # Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+    s/(?<!\\)\\\[/\\begin{SQUAREBRACKET}/sg;
+    s/\\\]/\\end{SQUAREBRACKET}/sg;
+    # add final token " STOP"
+    $_ .= " STOP"
+  }
+  return(@leadin);
+}
+
+#hashstring=tohash(\%hash,$string)
+# creates a hash value based on string and stores in %hash
+sub tohash {
+  my ($hash,$string)=@_;
+  my (@arr,$val);
+  my ($sum,$i)=(0,1);
+  my ($hstr);
+
+  @arr=unpack('c*',$string);
+
+  foreach $val (@arr) {
+    $sum += $i*$val;
+    $i++;
+  }
+  $hstr= "$sum";
+  if (defined($hash->{$hstr}) && $string ne $hash->{$hstr}) {
+    warn "Repeated hash value for verbatim mode in spite of different content.";
+    $hstr="-$hstr";
+  }
+  $hash->{$hstr}=$string;
+  return($hstr);
+}
+
+#string=fromhash(\%hash,$fromstring)
+# restores string value stored in hash
+#string=fromhash(\%hash,$fromstring,$prependstring)
+# additionally begins each line with prependstring
+sub fromhash {
+  my ($hash,$hstr)=($_[0],$_[1]);
+  my $retstr=$hash->{$hstr};
+  if ( $#_ >= 2) {
+    $retstr =~ s/^/$_[2]/mg;
+  }
+  return $retstr;
+}
+
+
+# postprocess($string, ..)
+# carry out the following post-processing steps for all arguments:
+# * Remove STOP token from the end
+# * Replace \RIGHTBRACE by }
+# 1. Check all deleted blocks: 
+#    a.where a deleted block contains a matching \begin and
+#      \end environment (these will be disabled by a %DIFDELCMD statements), for selected environment enable enable
+#      these commands again (such that for example displayed math in a deleted equation
+#      is properly within math mode.  For math mode environments replace numbered equation
+#      environments with their display only variety (so that equation numbers in new file and
+#      diff file are identical).  Where the correct type of math environment cannot be determined
+#      use a place holder MATHMODE
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+#    Replace all MATHMODE environment commands by the correct environment to achieve matching
+#    pairs
+#    c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+# 2. Remove DIFadd, DIFdel, DIFFaddbegin , ... from picture environments
+# 3. Convert DIFadd, DIFdel, DIFFaddbegin , ... into FL varieties
+#    within floats (currently recognised float environments: plate,table,figure
+#    plus starred varieties).
+# 4. Remove empty %DIFDELCMD < lines 
+# 4. Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+#    Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+# 6. Convert  \SUBSCRIPTNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+# 7. Expand hashes of verb and verbatim environments
+# 8. Convert '\PERCENTAGE ' back into '\%'
+# 9.. remove all \PAR tokens
+# 10.  package specific processing:  endfloat: make sure \begin{figure} and \end{figure} are always
+#      on a line by themselves, similarly for table environment
+#  4, undo renaming of the \begin and \end in comments
+
+#
+# Note have to manually synchronize substitution commands below and 
+# DIF.. command names in the header
+sub postprocess {
+  my ($begin,$len,$cnt,$float,$delblock,$addblock);
+  # second level blocks
+  my ($begin2,$cnt2,$len2,$eqarrayblock,$mathblock);
+
+  for (@_) { 
+
+    # change $'s in comments to something harmless
+    1 while s/(%.*)\$/$1DOLLARDIF/mg ;
+
+    # Remove final STOP token
+    s/ STOP$//;
+    # Replace \RIGHTBRACE by }    
+    s/\\RIGHTBRACE/}/g;
+    # Check all deleted blocks: where a deleted block contains a matching \begin and
+    #    \end environment (these will be disabled by a %DIFDELCMD statements), enable
+    #    these commands again (such that for example displayed math in a deleted equation
+    #    is properly within math mode.  For math mode environments replace numbered equation
+    #    environments with their display only variety (so that equation numbers in new file and
+    #    diff file are identical
+    while ( m/\\DIFdelbegin.*?\\DIFdelend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $delblock=$&;
+
+
+      ### (.*?[^\n]?)\n? construct is necessary to avoid empty lines in math mode, which result in
+      ### an error
+      # displayed math environments
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHREPL}$AUXCMD\n$1$3\n\\end{$MATHREPL}$AUXCMD\n$4/sg;
+      # also transform the opposite pair \end{displaymath} .. \begin{displaymath} but we have to be careful not to interfere with the results of the transformation in the line directly above
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHENV}; if found add \begin{$MATHREPL} and insert \end{$MATHREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+
+      # equation array environment
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHARRREPL}$AUXCMD\n$1$3\n\\end{$MATHARRREPL}$AUXCMD\n$4/sg;
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHARRENV}; if found add \begin{$MATHARRREPL} and insert \end{$MATHARRREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHARRREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHARRREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+      # parse $delblock for deleted and reinstated eqnarray* environments - within those reinstate \\ and & commands
+      while ( $delblock =~ m/\\begin\Q{$MATHARRREPL}$AUXCMD\E\n.*?\n\\end\Q{$MATHARRREPL}$AUXCMD\E\n/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$eqarrayblock=$&;
+	# reinstate deleted & and \\ commands
+	$eqarrayblock=~ s/(\%DIFDELCMD < \s*(\&|\\\\)\s*?(?:$DELCMDCLOSE|\n))/$1$2$AUXCMD\n/sg ;
+
+	substr($delblock,$begin2,$len2)=$eqarrayblock;
+	pos($delblock) = $begin2 + length($eqarrayblock);
+      }
+
+
+
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+      $delblock=~ s/\\($COUNTERCMD)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*\s*${AUXCMD}\n)/\\$1$2\\addtocounter{$1}{-1}${AUXCMD}\n/sg ;
+#     c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+      while ( $delblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($delblock,$begin2,$len2)=$mathblock;
+	pos($delblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified delblock
+      substr($_,$begin,$len)=$delblock;
+      pos = $begin + length($delblock);
+    }
+    # make the array modification in added blocks
+    while ( m/\\DIFaddbegin.*?\\DIFaddend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $addblock=$&;
+      while ( $addblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($addblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($addblock,$begin2,$len2)=$mathblock;
+	pos($addblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified addblock
+      substr($_,$begin,$len)=$addblock;
+      pos = $begin + length($addblock);
+    }
+
+
+    ### old place for BEGINDIF, ENDDIF replacement
+    # change begin and end commands  within comments such that they
+    # don't disturb the pattern matching (if there are several \begin or \end in one line
+    # this substitution is insufficient but that appears unlikely)
+    s/(%.*)\\begin\{(.*)$/$1\\BEGINDIF\{$2/mg ;
+    s/(%.*)\\end\{(.*)$/$1\\ENDDIF\{$2/mg ;
+
+    # Replace MATHMODE environments from step 1a above by the correct Math environment
+
+    # The next line is complicated.  The negative look-ahead insertion makes sure that no \end{$MATHENV} (or other mathematical
+    # environments) are between the \begin{$MATHENV} and \end{MATHMODE} commands. This is necessary as the minimal matching 
+    # is not globally minimal but only 'locally' (matching is beginning from the left side of the string)
+    1 while s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}((?:.(?!(?:\\end{(?:(?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}|\\begin{MATHMODE})))*?)\\end{MATHMODE}/\\begin{$1}$2\\end{$1}/s;
+    1 while s/\\begin{MATHMODE}((?:.(?!\\end{MATHMODE}))*?)\\end{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}/\\begin{$2}$1\\end{$2}/s;
+    # convert remaining \begin{MATHMODE} \end{MATHMODE} (and not containing & or \\ )into MATHREPL environments
+    s/\\begin{MATHMODE}((?:(.(?!(?<!\\)\&|\\\\))*)?)\\end{MATHMODE}/\\begin{$MATHREPL}$1\\end{$MATHREPL}/sg;
+    # others into MATHARRREPL
+    s/\\begin{MATHMODE}(.*?)\\end{MATHMODE}/\\begin{$MATHARRREPL}$1\\end{$MATHARRREPL}/sg;
+
+    # now look for AUXCMD math-mode pairs which have only comments (or empty lines between them), and remove the added commands
+    s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}$AUXCMD\n((?:\s*%.[^\n]*\n)*)\\end{\1}$AUXCMD\n/$2/sg; 
+
+
+    # Remove all mark up within picture environments
+    while ( m/\\begin\{($PICTUREENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin //g;
+      $float =~ s/\\DIFaddend //g;
+      $float =~ s/\\DIFadd\{($pat4)\}/$1/g;
+      $float =~ s/\\DIFdelbegin //g;
+      $float =~ s/\\DIFdelend //g;
+      $float =~ s/\\DIFdel\{($pat4)\}//g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    # Convert DIFadd, DIFdel, DIFFaddbegin , ... into  varieties
+    #    within floats (currently recognised float environments: plate,table,figure
+    #    plus starred varieties).
+    while ( m/\\begin\{($FLOATENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin /\\DIFaddbeginFL /g;
+      $float =~ s/\\DIFaddend /\\DIFaddendFL /g;
+      $float =~ s/\\DIFadd\{/\\DIFaddFL{/g;
+      $float =~ s/\\DIFdelbegin /\\DIFdelbeginFL /g;
+      $float =~ s/\\DIFdelend /\\DIFdelendFL /g;
+      $float =~ s/\\DIFdel\{/\\DIFdelFL{/g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    ### former location of undo renaming of \begin and \end in comments
+
+    # remove empty DIFCMD < lines
+    s/^\Q${DELCMDOPEN}\E\n//msg;
+
+    # Expand hashes of verb and verbatim environments (note negative look behind assertion to not leak out of DIFDELCMD comments
+    s/(\\verb\*?)\{([-\d]*?)\}/"${1}". fromhash(\%verbhash,$2)/esg;
+    s/${DELCMDOPEN}\\(verbatim\*?)\{([-\d]*?)\}/"${DELCMDOPEN}\\begin{${1}}".fromhash(\%verbhash,$2,$DELCMDOPEN)."${DELCMDOPEN}\\end{${1}}"/esg;
+    s/\\(verbatim\*?)\{([-\d]*?)\}/"\\begin{${1}}".fromhash(\%verbhash,$2)."\\end{${1}}"/esg;
+    # Convert '\PERCENTAGE ' back into '\%'			       
+    s/\\PERCENTAGE /\\%/g;
+    # remove all \PAR tokens (taking care to properly keep commented out PAR's
+    # from introducing uncommented newlines - next line)
+    s/(%DIF < )([^\n]*?)\\PAR\n/$1$2\n$1\n/sg;
+    # convert PAR commands which are on a line by themselves
+    s/\n(\s*?)\\PAR\n/\n\n/sg;
+    # convert remaining PAR commands (which are preceded by non-white space characters, usually "}" ($ADDCLOSE)
+    s/\\PAR\n/\n\n/sg;
+
+    #  package specific processing: 
+    if ( defined($packages{"endfloat"})) {
+      #endfloat: make sure \begin{figure} and \end{figure} are always
+      #      on a line by themselves, similarly for table environment
+      print STDERR "endfloat package detected.\n" if $verbose ;
+      # eliminate whitespace before and after
+      s/^(\s*)(\\(?:begin|end)\{(?:figure|table)\})(\s*)$/$2/mg;
+      # split lines with remaining characters before float enviroment conmmand
+      s/^(.+)(\\(?:begin|end)\{(?:figure|table)\})/$1\n$2/mg;
+      # split lines with remaining characters after float enviroment conmmand
+      s/(\\(?:begin|end)\{(?:figure|table)\})(.+)$/$1\n$2/mg;
+    }
+    # undo renaming of the \begin and \end  and dollars in comments 
+    s/(%.*)\\BEGINDIF\{(.*)$/$1\\begin\{$2/mg ;
+    s/(%.*)\\ENDDIF\{(.*)$/$1\\end\{$2/mg ;
+    1 while s/(%.*)DOLLARDIF/$1\$/mg ;
+#   Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+    s/\\end{SQUAREBRACKET}/\\\]/sg;
+    s/\\begin{SQUAREBRACKET}/\\\[/sg;
+# 4. Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+    s/\\begin\{DOLLARDOLLAR\}(.*?)\\end\{DOLLARDOLLAR\}/\$\$$1\$\$/sg;
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+    s/\\SUPERSCRIPTNB{($pat0)}/^$1/g ;
+    s/\\SUPERSCRIPT{($pat4)}/^{$1}/g ;
+    # Convert  \SUBSCRIPNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+    s/\\SUBSCRIPTNB{($pat0)}/_$1/g ;
+    s/\\SUBSCRIPT{($pat4)}/_{$1}/g ;
+
+  return;
+  }
+}
+
+
+# @diffs=linediff(\@seq1, \@seq2)
+# mark up lines like this
+#%DIF mm-mmdnn
+#%< old deleted line(s)
+#%DIF -------
+#%DIF mmann-nn
+#new appended line %< 
+#%DIF -------
+# Future extension: mark change explicitly
+# Assumes: traverse_sequence traverses deletions before insertions in changed sequences
+#          all line numbers relative to line 0 (first line of real file)
+sub linediff {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $block = [];
+  my $retseq = [];
+  my @begin=('','',''); # dummy initialisation
+  my $instring ; 
+
+  my $discard = sub { @begin=('d',$_[0],$_[1]) unless scalar @$block ; 
+                      push(@$block, "%DIF < " . $seq1->[$_[0]]) };
+  my $add = sub { if (! scalar  @$block) {
+		    @begin=('a',$_[0],$_[1]) ;}
+		  elsif ( $begin[0] eq 'd' ) {
+                    $begin[0]='c'; $begin[2]=$_[1];
+		    push(@$block, "%DIF -------") }
+                  push(@$block,  $seq2->[$_[1]] . " %DIF > " ) };
+  my $match = sub { if ( scalar @$block ) {
+                      if ( $begin[0] eq 'd' && $begin[1]!=$_[0]-1) {
+			$instring = sprintf "%%DIF %d-%dd%d",$begin[1],$_[0]-1,$begin[2]; }
+		      elsif ( $begin[0] eq 'a' && $begin[2]!=$_[1]-1) {
+			$instring = sprintf "%%DIF %da%d-%d",$begin[1],$begin[2],$_[1]-1; }
+		      elsif ( $begin[0] eq 'c' ) {
+			$instring = sprintf "%%DIF %sc%s",
+			                     ($begin[1]==$_[0]-1) ? "$begin[1]" : $begin[1]."-".($_[0]-1)  , 
+			                     ($begin[2]==$_[1]-1) ? "$begin[2]" : $begin[2]."-".($_[1]-1)  ; }
+		      else {
+			$instring = sprintf "%%DIF %d%s%d",$begin[1],$begin[0],$begin[2]; }
+		      push @$retseq, $instring,@$block, "%DIF -------" ; 
+		      $block = []; 
+		    }
+		    push @$retseq, $seq2->[$_[1]]
+		  };
+  # key function: remove multiple spaces (such that insertion or deletion of redundant white space is not reported)
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  push @$retseq, @$block if scalar @$block; 
+
+  return wantarray ? @$retseq : $retseq ;
+}
+
+
+
+# init_regex_arr_data(\@array,"TOKEN INIT")
+# scans DATA file handel for line "%% TOKEN INIT" line
+# then appends each line not beginning with % into array (as a quoted regex)
+sub init_regex_arr_data {
+  my ($arr,$token)=@_;
+  my ($copy);
+  while (<DATA>) {
+    if ( m/^%%BEGIN $token\s*$/ ) {
+      $copy=1; }
+    elsif ( m/^%%END $token\s*/ )  {
+      last; }
+    chomp;
+    push (@$arr,qr/^$_$/) if ( $copy && !/^%/ ) ;
+  }
+  seek DATA,0,0;    # rewind DATA handle to file begin
+}
+
+
+# init_regex_arr_ext(\@array,$arg)
+# fills array with regular expressions.
+# if arg is a file name, then read in list of regular expressions from that file
+# (one expression per line)
+# Otherwise treat arg as a comma separated list of regular expressions
+sub init_regex_arr_ext {
+  my ($arr,$arg)=@_;
+  my $regex;
+  if ( -f $ arg ) {
+    open(FILE,"$arg") or die ("Couldn't open $arg: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@$arr,qr/^$_$/);
+    }
+    close(FILE);
+  }
+  else {
+    # assume it is a comma-separated list of reg-ex
+    foreach $regex (split(qr/(?<!\\),/,$arg)) {
+      $regex =~ s/\\,/,/g;
+      push (@$arr,qr/^$regex$/);
+    }
+  }
+}
+
+#exetime() returns time since last execution of this command
+#exetime(1) resets this time
+my $lasttime=-1;   # global variable for persistence
+sub exetime {
+  my $reset=0;
+  my $retval;
+  if ((scalar @_) >=1) {
+    $reset=shift;
+  }
+  if ($reset) {
+    $lasttime=times();
+  }
+  else {
+    $retval=times()-$lasttime;
+    $lasttime=$lasttime+$retval;
+    return($retval);
+  }
+}
+
+
+sub usage {
+  die <<"EOF"; 
+Usage: $0 [options] old.tex new.tex > diff.tex
+
+Compares two latex files and writes tex code to stdout, which has the same
+format as new.tex but has all changes relative to old.tex marked up or commented.
+
+--type=markupstyle
+-t markupstyle         Add code to preamble for selected markup style
+                       Available styles: UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+                                         CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR
+                       [ Default: UNDERLINE ]
+
+--subtype=markstyle
+-s markstyle           Add code to preamble for selected style for bracketing
+                       commands (e.g. to mark changes in  margin)
+                       Available styles: SAFE MARGINAL DVIPSCOL
+                       [ Default: SAFE ]
+
+--floattype=markstyle
+-f markstyle           Add code to preamble for selected style which 
+                       replace standard marking and markup commands within floats
+                       (e.g., marginal remarks cause an error within floats
+                       so marginal marking can be disabled thus)
+                       Available styles: FLOATSAFE IDENTICAL
+                       [ Default: FLOATSAFE ]
+
+--encoding=enc
+-e enc                 Specify encoding of old.tex and new.tex. Typical encodings are
+                       ascii, utf8, latin1, latin9.  A list of available encodings can be 
+                       obtained by executing 
+                       perl -MEncode -e 'print join ("\\n",Encode->encodings( ":all" )) ;'
+                       [Default encoding is utf8 unless the first few lines of the preamble contain
+                       an invocation "\\usepackage[..]{inputenc} in which case the 
+                       encoding chosen by this command is asssumed. Note that ASCII (standard
+                       latex) is a subset of utf8]
+
+--preamble=file
+-p file                Insert file at end of preamble instead of auto-generating
+                       preamble.  The preamble must define the following commands
+                       \\DIFaddbegin,\\DIFaddend,\\DIFadd{..},
+                       \\DIFdelbegin,\\DIFdelend,\\DIFdel{..},
+                       and varieties for use within floats
+                       \\DIFaddbeginFL,\\DIFaddendFL,\\DIFaddFL{..},
+                       \\DIFdelbeginFL,\\DIFdelendFL,\\DIFdelFL{..}
+                       (If this option is set -t, -s, and -f options
+                       are ignored.)
+
+--exclude-safecmd=exclude-file
+--exclude-safecmd="cmd1,cmd2,..."
+-A exclude-file 
+--replace-safecmd=replace-file
+--append-safecmd=append-file
+--append-safecmd="cmd1,cmd2,..."
+-a append-file         Exclude from, replace or append to the list of regex
+                       matching commands which are safe to use within the 
+                       scope of a \\DIFadd or \\DIFdel command.  The file must contain
+                       one Perl-RegEx per line (Comment lines beginning with # or % are
+                       ignored). A literal comma within the comma-separated list must be
+                       escaped thus "\\,",   Note that the RegEx needs to match the whole of 
+                       the token, i.e., /^regex\$/ is implied and that the initial
+                       "\\" of the command is not included. The --exclude-safecmd
+                       and --append-safecmd options can be combined with the --replace-safecmd 
+                       option and can be used repeatedly to add cumulatively to the lists.
+
+--exclude-textcmd=exclude-file 
+--exclude-textcmd="cmd1,cmd2,..."
+-X exclude-file
+--replace-textcmd=replace-file
+--append-textcmd=append-file
+--append-textcmd="cmd1,cmd2,..."
+-x append-file         Exclude from, replace or append to the list of regex
+                       matching commands whose last argument is text.  See
+                       entry for --exclude-safecmd directly above for further details.
+
+--replace-context1cmd=replace-file
+--append-context1cmd=append-file
+--append-context1cmd="cmd1,cmd2,..."
+                       Replace or append to the list of regex matching commands
+                       whose last argument is text but which require a particular
+                       context to work, e.g. \\caption will only work within a figure
+                       or table.  These commands behave like text commands, except when 
+                       they occur in a deleted section, when they are disabled, but their
+                       argument is shown as deleted text.
+
+--replace-context2cmd=replace-file
+--append-context2cmd=append-file
+--append-context2cmd="cmd1,cmd2,..."
+                       As corresponding commands for context1.  The only difference is that
+                       context2 commands are completely disabled in deleted sections, including
+                       their arguments.
+
+
+--config var1=val1,var2=val2,...
+-c var1=val1,..        Set configuration variables.
+-c configfile           Available variables: 
+                          MINWORDSBLOCK (integer)
+                          FLOATENV (RegEx)
+                          PICTUREENV (RegEx)
+                          MATHENV (RegEx)
+                          MATHREPL (String)
+                          MATHARRENV (RegEx)
+                          MATHARRREPL (String)
+                          ARRENV (RegEx)
+                          COUNTERCMD (RegEx)
+                       This option can be repeated.
+
+
+--packages=pkg1,pkg2,..
+                       Tell latexdiff that .tex file is processed with the packages in list 
+                       loaded.  This is normally not necessary if the .tex file includes the
+                       preamble, as the preamble is automatically scanned for \\usepackage commands.
+                       Use of the --packages option disables automatic scanning, so if for any
+                       reason package specific parsing needs to be switched off, use --packages=none.
+                       The following packages trigger special behaviour:
+                       endfloat hyperref amsmath
+                       [ Default: scan the preamble for \\usepackage commands to determine
+                         loaded packages.]
+
+--show-preamble        Print generated or included preamble commands to stdout.
+
+--show-safecmd         Print list of regex matching and excluding safe commands.
+
+--show-textcmd         Print list of regex matching and excluding commands with text argument.
+
+--show-config          Show values of configuration variables
+
+--show-all             Show all of the above
+
+   NB For all --show commands, no old.tex or new.tex file needs to be given, and no 
+      differencing takes place.
+
+--allow-spaces         Allow spaces between bracketed or braced arguments to commands
+                       [Default requires arguments to directly follow each other without 
+                                intervening spaces]
+
+--flatten              Replace \\input and \\include commands within body by the content
+                       of the files in their argument.  If \\includeonly is present in the
+                       preamble, only those files are expanded into the document. However, 
+                       no recursion is done, i.e. \\input and \\include commands within 
+                       included sections are not expanded.  The included files are assumed to 
+                       be located in the same directories as the old and new master files,
+                       respectively, making it possible to organise files into old and new directories.
+
+--help
+-h                     Show this help text.
+
+--ignore-warnings      Suppress warnings about inconsistencies in length between input
+                       and parsed strings and missing characters. 
+
+--verbose
+-V                     Output various status information to stderr during processing.
+                       Default is to work silently.
+
+--version              Show version number.
+EOF
+}
+
+=head1 NAME
+
+latexdiff - determine and markup differences between two latex files
+
+=head1 SYNOPSIS
+
+B<latexdiff> [ B<OPTIONS> ] F<old.tex> F<new.tex> > F<diff.tex>
+
+=head1 DESCRIPTION
+
+Briefly, I<latexdiff> is a utility program to aid in the management of
+revisions of latex documents. It compares two valid latex files, here
+called C<old.tex> and C<new.tex>, finds significant differences
+between them (i.e., ignoring the number of white spaces and position
+of line breaks), and adds special commands to highlight the
+differences.  Where visual highlighting is not possible, e.g. for changes
+in the formatting, the differences are
+nevertheless marked up in the source.
+
+The program treats the preamble differently from the main document.
+Differences between the preambles are found using line-based
+differencing (similarly to the Unix diff command, but ignoring white
+spaces).  A comment, "S<C<%DIF E<gt>>>" is appended to each added line, i.e. a 
+line present in C<new.tex> but not in C<old.tex>.  Discarded lines 
+ are deactivated by prepending "S<C<%DIF E<lt>>>". Changed blocks are preceded  by
+comment lines giving information about line numbers in the original files.  Where there are insignificant
+differences, the resulting file C<diff.tex> will be similar to
+C<new.tex>.  At the end of the preamble, the definitions for I<latexdiff> markup commands are inserted.
+In differencing the main body of the text, I<latexdiff> attempts to
+satisfy the following guidelines (in order of priority):
+
+=over 3
+
+=item 1
+
+If both C<old.tex> and C<new.tex> are valid LaTeX, then the resulting
+C<diff.tex> should also be valid LateX. (NB If a few plain TeX commands
+are used within C<old.tex> or C<new.tex> then C<diff.tex> is not
+guaranteed to work but usually will).
+
+=item 2
+
+Significant differences are determined on the level of
+individual words. All significant differences, including differences
+between comments should be clearly marked in the resulting source code
+C<diff.tex>.
+
+=item 3
+
+If a changed passage contains text or text-producing commands, then
+running C<diff.tex> through LateX should produce output where added
+and discarded passages are highlighted.
+
+=item 4
+
+Where there are insignificant differences, e.g. in the positioning of
+line breaks, C<diff.tex> should follow the formatting of C<new.tex>
+
+=back
+
+For differencing the same algorithm as I<diff> is used but words
+instead of lines are compared.  An attempt is made to recognize
+blocks which are completely changed such that they can be marked up as a unit.
+Comments are differenced line by line
+but the number of spaces within comments is ignored. Commands including
+all their arguments are generally compared as one unit, i.e., no mark-up
+is inserted into the arguments of commands.  However, for a selected
+number of commands (for example, C<\caption> and all sectioning
+commands) the last argument is known to be text. This text is
+split into words and differenced just as ordinary text (use options to
+show and change the list of text commands, see below). As the
+algorithm has no detailed knowledge of LaTeX, it assumes all pairs of
+curly braces immediately following a command (i.e. a sequence of
+letters beginning with a backslash) are arguments for that command.
+As a restriction to condition 1 above it is thus necessary to surround
+all arguments with curly braces, and to not insert
+extraneous spaces.  For example, write 
+
+  \section{\textem{This is an emphasized section title}}
+
+and not
+
+  \section {\textem{This is an emphasized section title}}
+
+or
+
+  \section\textem{This is an emphasized section title}
+
+even though all varieties are the same to LaTeX (but see
+B<--allow-spaces> option which allows the second variety).
+
+For environments whose content does not conform to standard LaTeX or
+where graphical markup does not make sense all markup commands can be
+removed by setting the PICTUREENV configuration variable, set by
+default to C<picture> and C<DIFnomarkup> environments; see B<--config>
+option).  The latter environment (C<DIFnomarkup>) can be used to
+protect parts of the latex file where the markup results in illegal
+markup. You have to surround the offending passage in both the old and
+new file by C<\begin{DIFnomarkup}> and C<\end{DIFnomarkup}>. You must
+define the environment in the preambles of both old and new
+documents. I prefer to define it as a null-environment,
+
+C<\newenvironment{DIFnomarkup}{}{}>
+
+but the choice is yours.  Any markup within the environment will be
+removed, and generally everything within the environment will just be
+taken from the new file.
+
+It is also possible to difference files which do not have a preamble. 
+ In this case, the file is processed in the main document
+mode, but the definitions of the markup commands are not inserted.
+
+All markup commands inserted by I<latexdiff> begin with "C<\DIF>".  Added
+blocks containing words, commands or comments which are in C<new.tex>
+but not in C<old.tex> are marked by C<\DIFaddbegin> and C<\DIFaddend>.
+Discarded blocks are marked by C<\DIFdelbegin> and C<\DIFdelend>.
+Within added blocks all text is highlighted with C<\DIFadd> like this:
+C<\DIFadd{Added text block}>
+Selected `safe' commands can be contained in these text blocks as well
+(use options to show and change the list of safe commands, see below).
+All other commands as well as braces "{" and "}" are never put within
+the scope of C<\DIFadd>.  Added comments are marked by prepending
+"S<C<%DIF E<gt> >>".
+
+Within deleted blocks text is highlighted with C<\DIFdel>.  Deleted
+comments are marked by prepending "S<C<%DIF E<lt> >>".  Non-safe command
+and curly braces within deleted blocks are commented out with 
+"S<C<%DIFDELCMD E<lt> >>".
+
+
+
+=head1 OPTIONS
+
+=head2 Preamble
+
+The following options determine the visual markup style by adding the appropriate
+command definitions to the preamble. See the end of this section for a description of 
+available styles.
+
+=over 4
+
+=item B<--type=markupstyle> or
+B<-t markupstyle>
+
+Add code to preamble for selected markup style. This option defines
+C<\DIFadd> and C<\DIFdel> commands.
+Available styles: 
+
+C<UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR>
+
+[ Default: C<UNDERLINE> ]
+
+=item B<--subtype=markstyle> or
+B<-s markstyle> 
+
+Add code to preamble for selected style for bracketing
+commands (e.g. to mark changes in  margin). This option defines
+C<\DIFaddbegin>, C<\DIFaddend>, C<\DIFdelbegin> and C<\DIFdelend> commands.
+Available styles: C<SAFE MARGINAL DVIPSCOL>
+
+[ Default: C<SAFE> ]
+
+=item B<--floattype=markstyle> or
+B<-f markstyle>
+
+Add code to preamble for selected style which 
+replace standard marking and markup commands within floats
+(e.g., marginal remarks cause an error within floats
+so marginal marking can be disabled thus). This option defines all 
+C<\DIF...FL> commands.
+Available styles: C<FLOATSAFE TRADITIONALSAFE IDENTICAL>
+
+[ Default: C<FLOATSAFE> ]
+
+=item B<--encoding=enc> or 
+B<-e enc>
+
+Specify encoding of old.tex and new.tex. Typical encodings are
+C<ascii>, C<utf8>, C<latin1>, C<latin9>.  A list of available encodings can be 
+obtained by executing 
+
+C<perl -MEncode -e 'print join ("\n",Encode->encodings( ":all" )) ;' >
+
+[Default encoding is utf8 unless the first few lines of the preamble contain
+an invocation C<\usepackage[..]{inputenc}> in which case the 
+encoding chosen by this command is asssumed. Note that ASCII (standard
+latex) is a subset of utf8]
+
+=item B<--preamble=file> or
+B<-p file>
+
+Insert file at end of preamble instead of generating
+preamble.  The preamble must define the following commands
+C<\DIFaddbegin, \DIFaddend, \DIFadd{..},
+\DIFdelbegin,\DIFdelend,\DIFdel{..},>
+and varieties for use within floats
+C<\DIFaddbeginFL, \DIFaddendFL, \DIFaddFL{..},
+\DIFdelbeginFL, \DIFdelendFL, \DIFdelFL{..}>
+(If this option is set B<-t>, B<-s>, and B<-f> options
+are ignored.)
+
+=item B<--packages=pkg1,pkg2,..> 
+
+Tell latexdiff that .tex file is processed with the packages in list
+loaded.  This is normally not necessary if the .tex file includes the
+preamble, as the preamble is automatically scanned for C<\usepackage> commands.
+Use of the B<--packages> option disables automatic scanning, so if for any
+reason package specific parsing needs to be switched off, use B<--packages=none>.
+The following packages trigger special behaviour:
+
+=over 8
+
+=item C<amsmath> 
+
+Configuration variable amsmath is set to C<align*> (Default: C<eqnarray*>)
+
+=item C<endfloat> 
+
+Ensure that C<\begin{figure}> and C<\end{figure}> always appear by themselves on a line.
+
+=item C<hyperref>
+
+Change name of C<\DIFadd> and C<\DIFdel> commands to C<\DIFaddtex> and C<\DIFdeltex> and 
+define new C<\DIFadd> and C<\DIFdel> commands, which provide a wrapper for these commands,
+using them for the text but not for the link defining command (where any markup would cause
+errors).
+
+=back
+
+[ Default: scan the preamble for C<\\usepackage> commands to determine
+  loaded packages.]
+
+
+
+=item B<--show-preamble>
+
+Print generated or included preamble commands to stdout.
+
+=back
+
+=head2 Configuration
+
+=over 4
+
+=item B<--exclude-safecmd=exclude-file> or
+B<-A exclude-file> or  B<--exclude-safecmd="cmd1,cmd2,...">
+
+=item B<--replace-safecmd=replace-file>
+
+=item B<--append-safecmd=append-file> or 
+B<-a append-file> or B<--append-safecmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions (RegEx)
+matching commands which are safe to use within the 
+scope of a C<\DIFadd> or C<\DIFdel> command.  The file must contain
+one Perl-RegEx per line (Comment lines beginning with # or % are
+ignored).  Note that the RegEx needs to match the whole of 
+the token, i.e., /^regex$/ is implied and that the initial
+"\" of the command is not included. 
+The B<--exclude-safecmd> and B<--append-safecmd> options can be combined with the -B<--replace-safecmd> 
+option and can be used repeatedly to add cumulatively to the lists.
+ B<--exclude-safecmd>
+and B<--append-safecmd> can also take a comma separated list as input. If a
+comma for one of the regex is required, escape it thus "\,". In most cases it
+will be necessary to protect the comma-separated list from the shell by putting
+it in quotation marks.
+
+=item B<--exclude-textcmd=exclude-file> or
+B<-X exclude-file> or B<--exclude-textcmd="cmd1,cmd2,...">
+
+=item B<--replace-textcmd=replace-file>
+
+=item B<--append-textcmd=append-file> or 
+B<-x append-file> or B<--append-textcmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions
+matching commands whose last argument is text.  See
+entry for B<--exclude-safecmd> directly above for further details.
+
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context1cmd=append-file> or
+=item B<--append-context1cmd="cmd1,cmd2,...">
+
+Replace or append to the list of regex matching commands
+whose last argument is text but which require a particular
+context to work, e.g. \caption will only work within a figure
+or table.  These commands behave like text commands, except when 
+they occur in a deleted section, when they are disabled, but their
+argument is shown as deleted text.
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context2cmd=append-file> or
+=item B<--append-context2cmd="cmd1,cmd2,...">
+As corresponding commands for context1.  The only difference is that
+context2 commands are completely disabled in deleted sections, including
+their arguments.
+
+
+
+=item B<--config var1=val1,var2=val2,...> or B<-c var1=val1,..>
+
+=item B<-c configfile>
+
+Set configuration variables.  The option can be repeated to set different
+variables (as an alternative to the comma-separated list).
+Available variables (see below for further explanations): 
+
+C<MINWORDSBLOCK> (integer)
+
+C<FLOATENV> (RegEx)
+
+C<PICTUREENV> (RegEx)
+
+C<MATHENV> (RegEx)
+
+C<MATHREPL> (String)
+
+C<MATHARRENV> (RegEx)
+
+C<MATHARRREPL> (String)
+
+C<ARRENV> (RegEx)
+
+C<COUNTERCMD> (RegEx)
+
+=item B<--show-safecmd>
+
+Print list of RegEx matching and excluding safe commands.
+
+=item B<--show-textcmd>
+
+Print list of RegEx matching and excluding commands with text argument.
+
+=item B<--show-config>
+
+Show values of configuration variables.
+
+=item B<--show-all>
+
+Combine all --show commands.
+
+NB For all --show commands, no C<old.tex> or C<new.tex> file needs to be specified, and no 
+differencing takes place.
+
+
+=back
+
+=head2 Miscellaneous
+
+=over 4
+
+=item B<--verbose> or B<-V>
+
+Output various status information to stderr during processing.
+Default is to work silently.
+
+=item B<--ignore-warnings>
+
+Suppress warnings about inconsistencies in length between input and
+parsed strings and missing characters.  These warning messages are
+often related to non-standard latex or latex constructions with a
+syntax unknown to C<latexdiff> but the resulting difference argument
+is often fully functional anyway, particularly if the non-standard
+latex only occurs in parts of the text which have not changed.
+
+=item B<--allow-spaces>
+
+Allow spaces between bracketed or braced arguments to commands.  Note
+that this option might have undesirable side effects (unrelated scope
+might get lumpeded with preceding commands) so should only be used if the
+default produces erroneous results.  (Default requires arguments to
+directly follow each other without intervening spaces).
+
+=item B<--flatten>
+
+Replace C<\input> and C<\include> commands within body by the content
+of the files in their argument.  If C<\includeonly> is present in the
+preamble, only those files are expanded into the document. However, 
+no recursion is done, i.e. C<\input> and C<\include> commands within 
+included sections are not expanded.  The included files are assumed to 
+ be located in the same directories as the old and new master files,
+respectively, making it possible to organise files into old and new directories. 
+
+Use of this option is not recommended
+primarily the processing time for the large documents is prohibitive, and
+the resulting difference document no longer reflects the structure of the 
+input documents. 
+
+=item B<--help> or
+B<-h>
+
+Show help text
+
+=item B<--version>
+
+Show version number
+
+=back
+
+=head2 Predefined styles 
+
+=head2 Major types
+
+The major type determine the markup of plain text and some selected latex commands outside floats by defining the markup commands C<\DIFadd{...}> and C<\DIFdel{...}> .
+
+=over 10
+
+=item C<UNDERLINE>
+
+Added text is wavy-underlined and blue, discarded text is struck out and red
+(Requires color and ulem packages).  Overstriking does not work in displayed math equations such that deleted parts of equation are underlined, not struck out (this is a shortcoming inherent to the ulem package).
+
+=item C<CTRADITIONAL>
+
+Added text is blue and set in sans-serif, and a red footnote is created for each discarded 
+piece of text. (Requires color package)
+
+=item C<TRADITIONAL>
+
+Like C<CTRADITIONAL> but without the use of color.
+
+=item C<CFONT>
+
+Added text is blue and set in sans-serif, and discarded text is red and very small size.
+
+=item C<FONTSTRIKE>
+
+Added tex is set in sans-serif, discarded text small and struck out
+
+=item C<CCHANGEBAR>
+
+Added text is blue, and discarded text is red.  Additionally, the changed text is marked with a bar in the margin (Requires color and changebar packages).
+
+=item C<CFONTCHBAR>
+
+Like C<CFONT> but with additional changebars (Requires color and changebar packages).
+
+=item C<CULINECHBAR>
+
+Like C<UNDERLINE> but with additional changebars (Requires color, ulem and changebar packages).
+
+=item C<CHANGEBAR>
+
+No mark up of text, but mark margins with changebars (Requires changebar package).
+
+=item C<INVISIBLE>
+
+No visible markup (but generic markup commands will still be inserted.
+
+=back
+
+=head2 Subtypes
+
+The subtype defines the commands that are inserted at the begin and end of added or discarded blocks, irrespectively of whether these blocks contain text or commands (Defined commands: C<\DIFaddbegin, \DIFaddend, \DIFdelbegin, \DIFdelend>) 
+
+=over 10
+
+=item C<SAFE>
+
+No additional markup (Recommended choice)
+
+=item C<MARGIN>
+
+Mark beginning and end of changed blocks with symbols in the margin nearby (using
+the standard C<\marginpar> command - note that this sometimes moves somewhat
+from the intended position.
+
+=item C<DVIPSCOL>
+
+An alternative way of marking added passages in blue, and deleted ones in red. Note
+that C<DVIPSCOL> only works with the dvips converter, e.g. not pdflatex.
+(it is recommeneded to use instead the main types to effect colored markup,
+although in some cases coloring with dvipscol can be more complete).
+
+=back
+
+=head2 Float Types
+
+Some of the markup used in the main text might cause problems when used within 
+floats (e.g. figures or tables).  For this reason alternative versions of all
+markup commands are used within floats. The float type defines these alternative commands.
+
+=over 10
+
+=item C<FLOATSAFE>
+
+Use identical markup for text as in the main body, but set all commands marking the begin and end of changed blocks to null-commands.  You have to choose this float type if your subtype is C<MARGIN> as C<\marginpar> does not work properly within floats.
+
+=item C<TRADITIONALSAFE>
+
+Mark additions the same way as in the main text.  Deleted environments are marked by angular brackets \[ and \] and the deleted text is set in scriptscript size. This float type should always be used with the C<TRADITIONAL> and  C<CTRADITIONAL> markup types as the \footnote command does not work properly in floating environments.
+
+=item C<IDENTICAL>
+
+Make no difference between the main text and floats.
+
+=back
+
+
+=head2 Configuration Variables
+
+=over 10
+
+=item C<MINWORDSBLOCK>
+
+Minimum number of tokens required to form an independent block. This value is
+used in the algorithm to detect changes of complete blocks by merging identical text parts of less than C<MINWORDSBLOCK> to the preceding added and discarded parts.
+
+[ Default: 3 ]
+
+=item C<FLOATENV>
+
+Environments whose name matches the regular expression in C<FLOATENV> are 
+considered floats.  Within these environments, the I<latexdiff> markup commands
+are replaced by their FL variaties.
+
+[ Default: S<C<(?:figure|table|plate)[\w\d*@]*> >]
+
+=item C<PICTUREENV>
+
+Within environments whose name matches the regular expression in C<PICTUREENV>
+all latexdiff markup is removed (in pathologic cases this might lead to
+ inconsistent markup but this situation should be rare).
+
+[ Default: S<C<(?:picture|DIFnomarkup)[\w\d*@]*> >]
+
+=item C<MATHENV>,C<MATHREPL>
+
+If both \begin and \end for a math environment (environment name matching C<MATHENV>
+or \[ and \])
+are within the same deleted block, they are replaced by a \begin and \end commands for C<MATHREPL>
+rather than being commented out.
+
+[ Default: C<MATHENV>=S<C<(?:displaymath|equation)> >, C<MATHREPL>=S<C<displaymath> >]
+
+=item C<MATHARRENV>,C<MATHARRREPL>
+
+as C<MATHENV>,C<MATHREPL> but for equation arrays
+
+[ Default: C<MATHARRENV>=S<C<eqnarray\*?> >, C<MATHREPL>=S<C<eqnarray> >]
+
+=item C<ARRENV>
+
+If a match to C<ARRENV> is found within an inline math environment within a deleted or added block, then the inlined math 
+is surrounded by C<\mbox{>...C<}>.  This is necessary as underlining does not work within inlined array environments.
+
+[ Default: C<ARRENV>=S<C<(?:array|[pbvBV]matrix)> >
+
+=item C<COUNTERCMD>
+
+If a command in a deleted block which is also in the textcmd list matches C<COUNTERCMD> then an
+additional command C<\addtocounter{>F<cntcmd>C<}{-1}>, where F<cntcmd> is the matching command, is appended in the diff file such that the numbering in the diff file remains synchronized with the
+numbering in the new file.
+
+[ Default: C<COUNTERCMD>=C<(?:footnote|part|section|subsection> ...
+
+C<|subsubsection|paragraph|subparagraph)>  ]
+
+=back
+
+=head1 BUGS
+
+UTF-8 support requires a relatively new version of perl (5.8.0 is sufficient 
+but 5.6.2 up would work OK, too).
+
+Option allow-spaces not implemented entirely consistently. It breaks
+the rules that number and type of white space does not matter, as
+different numbers of inter-argument spaces are treated as significant.
+
+Please send bug reports
+to I<tilmann@esc.cam.ac.uk>.  Include the serial number of I<latexdiff>
+(from comments at the top of the source or use B<--version>).  If you come across latex
+files that are error-free and conform to the specifications set out
+above, and whose differencing still does not result in error-free
+latex, please send me those files, ideally edited to only contain the
+offending passage as long as that still reproduces the problem. 
+
+=head1 SEE ALSO
+
+L<latexrevise>
+
+=head1 PORTABILITY
+
+I<latexdiff> does not make use of external commands and thus should run
+on any platform  supporting Perl 5.6 or higher.  If files with encodings 
+other than ASCII or UTF-8 are processed, Perl 5.8 or higher is required.
+
+The standard version of I<latexdiff> requires installation of the Perl package
+C<Algorithm::Diff> (available from I<www.cpan.org> - 
+I<http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15>) but a stand-alone
+version, I<latexdiff-so>, which has this package inlined, is available, too.
+I<latexdiff-fast> requires the I<diff> command to be present.
+
+=head1 AUTHOR
+
+Copyright (C) 2004-2007 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+
+Contributors of fixes and additions: V. Kuhlmann, J. Paisley, N. Becker, T. Doerges, K. Huebner
+Thanks to everyone who send in bug reports.
+
+=cut
+
+__END__
+%%BEGIN SAFE COMMANDS
+% Regex matching commands which can safely be in the
+% argument of a \DIFadd or \DIFdel command (leave out the \)
+arabic
+dashbox
+emph
+fbox
+framebox
+hspace
+math.*
+makebox
+mbox
+pageref
+ref
+symbol
+raisebox
+rule
+text.*
+shortstack
+usebox
+dag
+ddag
+copyright
+pounds
+S
+P
+oe
+OE
+ae
+AE
+aa
+AA
+o
+O
+l
+L
+frac
+ss
+sqrt
+ldots
+cdots
+vdots
+ddots
+alpha
+beta
+gamma
+delta
+epsilon
+varepsilon
+zeta
+eta
+theta
+vartheta
+iota
+kappa
+lambda
+mu
+nu
+xi
+pi
+varpi
+rho
+varrho
+sigma
+varsigma
+tau
+upsilon
+phi
+varphi
+chi
+psi
+omega
+Gamma
+Delta
+Theta
+Lambda
+Xi
+Pi
+Sigma
+Upsilon
+Phi
+Psi
+Omega
+ps
+mp
+times
+div
+ast
+star
+circ
+bullet
+cdot
+cap
+cup
+uplus
+sqcap
+vee
+wedge
+setminus
+wr
+diamond
+(?:big)?triangle.*
+lhd
+rhd
+unlhd
+unrhd
+oplus
+ominus
+otimes
+oslash
+odot
+bigcirc
+d?dagger
+amalg
+leq
+prec
+preceq
+ll
+(?:sq)?su[bp]set(?:eq)?
+in
+vdash
+geq
+succ(?:eq)?
+gg
+ni
+dashv
+equiv
+sim(?:eq)?
+asymp
+approx
+cong
+neq
+doteq
+propto
+models
+perp
+mid
+parallel
+bowtie
+Join
+smile
+frown
+.*arrow
+(?:long)?mapsto
+.*harpoon.*
+leadsto
+aleph
+hbar
+imath
+jmath
+ell
+wp
+Re
+Im
+mho
+prime
+emptyset
+nabla
+surd
+top
+bot
+angle
+forall
+exists
+neg
+flat
+natural
+sharp
+backslash
+partial
+infty
+Box
+Diamond
+triangle
+clubsuit
+diamondsuit
+heartsuit
+spadesuit
+sum
+prod
+coprod
+int
+oint
+big(?:sq)?c[au]p
+bigvee
+bigwedge
+bigodot
+bigotimes
+bigoplus
+biguplus
+(?:arc)?(?:cos|sin|tan|cot)h?
+csc
+arg
+deg
+det
+dim
+exp
+gcd
+hom
+inf
+ker
+lg
+lim
+liminf
+limsup
+ln
+log
+max
+min
+Pr
+sec
+sup
+(SUPER|SUB)SCRIPTNB
+(SUPER|SUB)SCRIPT
+%%END SAFE COMMANDS
+
+%%BEGIN TEXT COMMANDS
+% Regex matching commands with a text argument (leave out the \)
+addcontents.*
+cc
+closing
+chapter
+dashbox
+emph
+encl
+fbox
+framebox
+footnote
+footnotetext
+framebox
+part
+(sub){0,2}section\*?
+(sub)?paragraph\*?
+makebox
+mbox
+opening
+parbox
+raisebox
+savebox
+sbox
+shortstack
+signature
+text.*
+value
+underline
+sqrt
+(SUPER|SUB)SCRIPT
+%%END TEXT COMMANDS 
+
+%%BEGIN CONTEXT1 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+caption
+%%END CONTEXT1 COMMANDS 
+
+%%BEGIN CONTEXT2 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+title
+author
+%%END CONTEXT2 COMMANDS 
+
+
+%% TYPES (Commands for highlighting changed blocks)
+
+%DIF UNDERLINE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue}\uwave{#1}}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}\sout{#1}}}                     
+%DIF END UNDERLINE PREAMBLE
+
+%DIF CTRADITIONAL PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} [..\footnote{removed: #1} ]}}
+%DIF END CTRADITIONAL PREAMBLE
+
+%DIF TRADITIONAL PREAMBLE
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{[..\footnote{removed: #1} ]}}
+%DIF END TRADITIONAL PREAMBLE
+
+%DIF CFONT PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} \scriptsize #1}}
+%DIF END CFONT PREAMBLE
+
+%DIF FONTSTRIKE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{\footnotesize \sout{#1}}}
+%DIF END FONTSTRIKE PREAMBLE
+
+%DIF CCHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}#1}\protect\cbdelete}
+%DIF END CCHANGEBAR PREAMBLE
+
+%DIF CFONTCHBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\sf #1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\scriptsize #1}\protect\cbdelete}
+%DIF END CFONTCHBAR PREAMBLE
+
+%DIF CULINECHBAR PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\uwave{#1}}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\sout{#1}}\protect\cbdelete}
+%DIF END CULINECHBAR PREAMBLE
+
+%DIF CHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\providecommand{\DIFadd}[1]{\protect\cbstart{#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete}
+%DIF END CHANGEBAR PREAMBLE
+
+%DIF INVISIBLE PREAMBLE
+\providecommand{\DIFadd}[1]{#1}
+\providecommand{\DIFdel}[1]{}
+%DIF END INVISIBLE PREAMBLE
+
+
+%% SUBTYPES (Markers for beginning and end of changed blocks)
+
+%DIF SAFE PREAMBLE
+\providecommand{\DIFaddbegin}{}
+\providecommand{\DIFaddend}{}
+\providecommand{\DIFdelbegin}{}
+\providecommand{\DIFdelend}{}
+%DIF END SAFE PREAMBLE
+
+%DIF MARGIN PREAMBLE
+\providecommand{\DIFaddbegin}{\protect\marginpar{a[}}
+\providecommand{\DIFaddend}{\protect\marginpar{]}}
+\providecommand{\DIFdelbegin}{\protect\marginpar{d[}}
+\providecommand{\DIFdelend}{\protect\marginpar{]}}
+%DIF END BRACKET PREAMBLE
+
+%DIF DVIPSCOL PREAMBLE
+%Note: only works with dvips converter
+\RequirePackage{color}
+\RequirePackage{dvipscol}
+\providecommand{\DIFaddbegin}{\protect\nogroupcolor{blue}}
+\providecommand{\DIFaddend}{\protect\nogroupcolor{black}}
+\providecommand{\DIFdelbegin}{\protect\nogroupcolor{red}}
+\providecommand{\DIFdelend}{\protect\nogroupcolor{black}}
+%DIF END DVIPSCOL PREAMBLE
+
+
+%% FLOAT TYPES 
+
+%DIF FLOATSAFE PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%DIF IDENTICAL PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{\DIFaddbegin}
+\providecommand{\DIFaddendFL}{\DIFaddend}
+\providecommand{\DIFdelbeginFL}{\DIFdelbegin}
+\providecommand{\DIFdelendFL}{\DIFdelend}
+%DIF END IDENTICAL PREAMBLE
+
+%DIF TRADITIONALSAFE PREAMBLE
+% procidecommand color to make this work for TRADITIONAL and CTRADITIONAL
+\providecommand{\color}[1]{}
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}[..{\scriptsize {removed: #1}} ]}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%% SPECIAL PACKAGE PREAMBLE COMMANDS
+
+% Standard \DIFadd and \DIFdel are redefined as \DIFaddtex and \DIFdeltex
+% when hyperref package is included.
+%DIF HYPERREF PREAMBLE
+\providecommand{\DIFadd}[1]{\texorpdfstring{\DIFaddtex{#1}}{#1}}
+\providecommand{\DIFdel}[1]{\texorpdfstring{\DIFdeltex{#1}}{}}
+%DIF END HYPERREF PACKAGE
diff --git a/Build/source/texk/texlive/linked_scripts/latexdiff/latexrevise b/Build/source/texk/texlive/linked_scripts/latexdiff/latexrevise
new file mode 100755
index 00000000000..279dac1fc6a
--- /dev/null
+++ b/Build/source/texk/texlive/linked_scripts/latexdiff/latexrevise
@@ -0,0 +1,523 @@
+#!/usr/bin/perl -w
+#   latexrevise - takes output file of latexdiff and removes either discarded
+#                 or appended passages, then deletes all other latexdiff markup
+#
+#   Copyright (C) 2004  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# Version 0.1   First public release
+# Version 0.3   Updated for compatibility with latexdiff 0.3 output (DIFAUXCMD removal)
+#
+
+use Getopt::Long ;
+use strict;
+
+# Markup strings (make sure that this are set to the same value as in 
+# latexdiff)
+# If at all possible, do not change these as parts of the program
+# depend on the actual name.
+# At the very least adapt subroutine postprocess to new tokens.
+
+# note: have to use three backslashes to mean one literal one (reason
+# unknown
+my $ADDMARKOPEN='\\\DIFaddbegin(?:FL)? ';   # Token to mark begin of appended text
+my $ADDMARKCLOSE='\\\DIFaddend(?:FL)?(?: |\z)';   # Token to mark end of appended text (|\z only deals with the case of \DIFaddend right before \end{document}
+my $ADDOPEN='\\\DIFadd(?:FL)?{';  # To mark begin of added text passage
+my $ADDCLOSE='}';        # To mark end of added text passage
+my $ADDCOMMENT='DIF > ';   # To mark added comment line
+my $DELMARKOPEN='\\\DIFdelbegin(?:FL)? ';   # Token to mark begin of deleted text
+my $DELMARKCLOSE='\\\DIFdelend(?:FL)?(?: |\z)';   # Token to mark end of deleted text
+my $DELOPEN='\\\DIFdel(?:FL)?{';  # To mark begin of deleted text passage
+my $DELCLOSE='}';        # To mark end of deleted text passage
+my $ALTEXT='FL';         # string which might be appended to above commands
+my $DELCMDOPEN='%DIFDELCMD < ';  # To mark begin of deleted commands (must begin with %, i.e., be a comment
+my $DELCMDCLOSE="%%%\n";    # To mark end of deleted commands (must end with a new line)
+my $AUXCMD='%DIFAUXCMD' ; #  follows auxiliary commands put in by latexdiff to make difference file legal
+my $DELCOMMENT='DIF < ';   # To mark deleted comment line
+
+my $PREAMBLEXTBEG='^%DIF PREAMBLE EXTENSION ADDED BY LATEXDIFF$';
+my $PREAMBLEXTEND='^%DIF END PREAMBLE EXTENSION ADDED BY LATEXDIFF$';
+
+
+my $pat0 = '(?:[^{}]|\\\{|\\\})*';
+my $pat1 = '(?:[^{}]|\\\{|\\\}|\{'.$pat0.'\})*';
+my $pat2 = '(?:[^{}]|\\\{|\\\}|\{'.$pat1.'\})*';
+my $pat3 = '(?:[^{}]|\\\{|\\\}|\{'.$pat2.'\})*';
+my $pat4 = '(?:[^{}]|\\\{|\\\}|\{'.$pat3.'\})*';
+my $brat0 = '(?:[^\[\]]|\\\[|\\\])*'; 
+
+
+my ($input,$preamble,$body,$post);
+my (@matches);
+my ($cnt,$prematch,$postmatch);
+my ($help);
+my ($verbose,$quiet,$accept,$decline,$simplify)=(0,0,0,0,0);
+my ($comment,$comenv,$markup,$markenv);
+
+# A word unlikely ever to be used in a real latex file
+my $someword='gobbledegooksygook';
+
+Getopt::Long::Configure('bundling');
+GetOptions('accept|a' => \$accept,
+	   'decline|d'=> \$decline,
+	   'simplify|s' => \$simplify,
+	   'comment|c=s' => \$comment,
+	   'comment-environment|e=s' => \$comenv,
+	   'markup|m=s' => \$markup,
+	   'markup-environment|n=s' => \$markenv,
+	   'no-warnings|q' => \$verbose,
+	   'verbose|V' => \$verbose,
+	   'help|h|H' => \$help);
+
+if ( $help ) {
+  usage() ;
+}
+
+if ( ($accept &&  $decline) || ($accept && $simplify) || ($decline && $simplify) ) {
+  die '-a,-d and -s options are mutually axclusive. Type latexrevise -h to get more help.';
+}
+
+
+
+print STDERR "ACCEPT mode\n" if $verbose && $accept;
+print STDERR "DECLINE mode\n" if $verbose && $decline;
+print STDERR "SIMPLIFY mode.  WARNING: The output will not normally be valid latex,\n" if $verbose && $simplify;
+
+# Slurp old and new files
+{ 
+  local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+  $input=<>;
+}
+
+# split into parts
+($preamble,$body,$post)=splitdoc($input,'\begin{document}','\end{document}');
+
+if (length $preamble && ( $accept || $decline ) ) {
+  #
+  # WORK ON PREAMBLE
+  #
+  # (compare subroutine linediff in latexdiff to make sure correct strings are used)
+  
+  # remove extra commands added to preamble by latexdiff 
+  $preamble =~ s/${PREAMBLEXTBEG}.*?${PREAMBLEXTEND}\n{0,1}//smg ;
+
+  if ( $accept ) {
+    # delete mark up in appended lines
+    $preamble =~ s/^(.*) %DIF > $/$1/mg ;
+  } elsif ( $decline ) {
+    # delete appended lines
+    #  $preamble =~ s/^(.*) %DIF > $//mg ;
+    $preamble =~ s/^(.*) %DIF > \n//mg ;
+    # delete markup in deleted lines
+    $preamble =~ s/^%DIF < //mg ;
+  }
+  # remove any remaining DIF markups
+  #$preamble =~ s/%DIF.*$//mg ;
+  $preamble =~ s/%DIF.*?\n//sg ;
+}
+#print $preamble ;
+
+#
+# WORK ON BODY
+#
+if ($accept) {
+  # remove ADDMARKOPEN, ADDMARKCLOSE tokens
+  @matches= $body =~ m/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/sg;
+  checkpure(@matches);
+  $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/$1/sg;
+  # remove text flanked by DELMARKOPEN, DELMARKCLOSE tokens
+  @matches= $body =~ m/${DELMARKOPEN}(.*?)${DELMARKCLOSE}/sg;
+  checkpure(@matches);
+  $body =~ s/${DELMARKOPEN}(.*?)${DELMARKCLOSE}//sg;
+  # remove markup of added comments
+  $body =~ s/%${ADDCOMMENT}(.*?)$/%$1/mg ;
+  # remove deleted comments (full line)
+  $body =~ s/^%${DELCOMMENT}.*?\n//mg ;
+  # remove deleted comments (part of line)
+  $body =~ s/%${DELCOMMENT}.*?$//mg ;
+} 
+elsif ( $decline) {
+  # remove DELMARKOPEN, DELMARKCLOSE tokens
+  @matches= $body =~ m/${DELMARKOPEN}(.*?)${DELMARKCLOSE}/sg;
+  checkpure(@matches);
+  $body =~ s/${DELMARKOPEN}(.*?)${DELMARKCLOSE}/$1/sg;
+  # remove text flanked by ADDMARKOPEN, ADDMARKCLOSE tokens
+  # as latexdiff algorithm keeps the formatting and white spaces
+  # of the new text, sometimes whitespace might be inserted or
+  # removed inappropriately.  We try to guess whether this has
+  # happened
+
+  # Mop up tokens. This must be done already now as otherwise 
+  # detection of white-space problems does not work
+  $cnt = $body =~ s/${DELOPEN}($pat4)${DELCLOSE}/$1/sg;
+  # remove markup of deleted commands 
+  $cnt +=   $body =~ s/${DELCMDOPEN}(.*?)${DELCMDCLOSE}/$1/sg ;
+  $cnt +=   $body =~ s/${DELCMDOPEN}//g ;
+  # remove aux commands
+  $cnt +=   $body =~ s/^.*${AUXCMD}$/${someword}/mg; $body =~ s/${someword}\n//g;
+
+  while ( $body =~ m/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/s ) {
+    $prematch=$`;
+    $postmatch=$';
+    checkpure($1);
+    if ( $prematch =~ /\w$/s && $postmatch =~ /^\w/ ) {
+      # apparently no white-space between word=>Insert white space
+      $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/ /s ;
+    }
+    elsif ( $prematch =~ /\s$/s && $postmatch =~ /^[.,;:]/ ) {
+      # space immediately before one of ".,:;" => remove this space
+      $body =~ s/\s${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}//s ;
+    }
+    else {
+      # do not insert or remove any extras
+      $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}//s;
+    }
+  }
+# Alternative without special cases treatment
+#  @matches= $body =~ m/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/sg;
+#  checkpure(@matches);
+#  $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}//sg;
+  # remove markup of deleted comments
+  $body =~ s/%${DELCOMMENT}(.*?)$/%$1/mg ;
+  # remove added comments (full line)
+  $body =~ s/^%${ADDCOMMENT}.*?\n//mg ;
+  # remove added comments (part of line)
+  $body =~ s/%${ADDCOMMENT}.*?$//mg ;
+}
+
+# remove any remaining tokens
+if ( $accept || $decline || $simplify ) {
+  # first substitution command deals with special case of added paragraph
+  $cnt = $body =~ s/${ADDOPEN}($pat4)\n${ADDCLOSE}\n/$1\n/sg;
+  $cnt += $body =~ s/${ADDOPEN}($pat4)${ADDCLOSE}/$1/sg;
+  $cnt==0 || warn 'Remaining $ADDOPEN tokens in DECLINE mode\n' unless ( $quiet || $accept || $simplify );
+}
+if ($accept || $simplify ) {
+  # Note: in decline mode these commands have already been removed above
+  $cnt = $body =~ s/${DELOPEN}($pat4)${DELCLOSE}/$1/sg;
+  #### remove markup of deleted commands 
+  $cnt +=   $body =~ s/${DELCMDOPEN}(.*?)${DELCMDCLOSE}/$1/sg ;
+  $cnt +=   $body =~ s/${DELCMDOPEN}//g ;
+  # remove aux commands
+  # $cnt +=   
+  $body =~ s/^.*${AUXCMD}$/${someword}/mg; $body =~ s/${someword}\n//g;
+
+  #### remove deleted comments 
+  ###$cnt += $body =~ s/${DIFDELCMD}.*?$//mg ;
+  $cnt==0 || warn 'Remaining $DELOPEN or $DIFDELCMD tokens in ACCEPT mode\n' unless ( $quiet || $simplify );
+}
+
+# Remove comment commands
+if (defined($comment)) {
+  print STDERR "Removing \\$comment\{..\} sequences ..." if $verbose;
+  # protect $comments in comments by making them look different
+  $body =~ s/(%.*)${comment}(.*)$/$1${someword}$2/mg ;
+  # carry out the substitution
+  $cnt = 0 + $body =~ s/\\${comment}(?:\[${brat0}\])?\{${pat4}\}//sg ;
+  print STDERR "$cnt matches found and removed.\n" if $verbose;
+  # and undo the protection substitution
+  $body =~ s/(%.*)${someword}(.*)$/$1${comment}$2/mg ;
+}
+if (defined($comenv)) {
+  print STDERR "Removing $comenv environments ..." if $verbose;
+  $body =~ s/(%.*)${comenv}/$1${someword}/mg ;
+##  $cnt = 0 + $body =~ s/\\begin(?:\[${brat0}\])?\{\$comenv\}.*?\\end\{\$comenv\}//sg ;
+    $cnt = 0 + $body =~ s/\\begin(?:\[${brat0}\])?\{${comenv}\}.*?\\end\{${comenv}\}\s*?\n//sg ;
+  print STDERR "$cnt matches found and removed.\n" if $verbose;
+  $body =~ s/(%.*)${someword}/$1${comenv}/mg ;
+}
+
+if (defined($markup)) {
+  print STDERR "Removing \\$markup\{..\} cpmmands ..." if $verbose;
+  # protect $markups in comments by making them look different
+  $body =~ s/(%.*)${markup}(.*)$/$1${someword}$2/mg ;
+  # carry out the substitution
+  $cnt = 0 + $body =~ s/\\${markup}(?:\[${brat0}\])?\{(${pat4})\}/$1/sg ;
+  print STDERR "$cnt matches found and removed.\n" if $verbose;
+  # and undo the protection substitution
+  $body =~ s/(%.*)${someword}(.*)$/$1${markup}$2/mg ;
+}
+if (defined($markenv)) {
+  print STDERR "Removing $markenv environments ..." if $verbose;
+  $body =~ s/(%.*)${markenv}/$1${someword}/mg ;
+  $cnt = 0 + $body =~ s/\\begin(?:\[${brat0}\])?\{${markenv}\}\n?//sg;
+  $cnt += 0 + $body =~ s/\\end\{${markenv}\}\n?//sg;
+  print STDERR $cnt/2, " matches found and removed.\n" if $verbose;
+  $body =~ s/(%.*)${someword}/$1${markenv}/mg ;
+}
+
+
+if ( length $preamble ) {
+  print "$preamble\\begin{document}${body}\\end{document}$post";
+} else {
+  print $body;
+}
+
+# checkpure(@matches)
+# checks whether any of the strings in matches contains
+# $ADDMARKOPEN, $ADDMARKCLOSE,$DELMARKOPEN, or $DELMARKCLOSE
+# If so, die reporting nesting problems, otherwise return to caller
+sub checkpure {
+  while (defined($_=shift)) {
+    if (  /$ADDMARKOPEN/ || /$ADDMARKCLOSE/
+	  || /$DELMARKOPEN/ || /$DELMARKCLOSE/ ) {
+      die <<EOF ;
+There is a problem with nesting of  $ADDMARKOPEN, $ADDMARKCLOSE,
+$DELMARKOPEN, and $DELMARKCLOSE tokens that prevents me from 
+processing the file.  Exiting ...
+EOF
+     }
+  }
+}
+
+# ($part1,$part2,$part3)=splitdoc($text,$word1,$word2)
+# splits $text into 3 parts at $word1 and $word2.
+# if neither $word1 nor $word2 exist, $part1 and $part3 are empty, $part2 is $text
+# If only $word1 or $word2 exist but not the other, output an error message.
+#
+# same subroutine as in latexdiff
+sub splitdoc {
+  my ($text,$word1,$word2)=@_;
+  my $l1 = length $word1 ;
+  my $l2 = length $word2 ;
+
+  my $i = index($text,$word1);
+  my $j = index($text,$word2);
+
+  my ($part1,$part2,$part3)=("","","");
+
+  if ( $i<0 && $j<0) {
+    # no $word1 or $word2
+    print STDERR "Old Document not a complete latex file. Assuming it is a tex file with no preamble.\n";
+    $part2 = $text;
+  } elsif ( $i>=0 && $j>$i ) {
+    $part1 = substr($text,0,$i) ; 
+    $part2 = substr($text,$i+$l1,$j-$i-$l1);
+    $part3 = substr($text,$j+$l2) unless $j+$l2 >= length $text;
+  } else {
+    die "$word1 or $word2 not in the correct order or not present as a pair."
+  }
+  return ($part1,$part2,$part3);
+}
+
+
+
+sub usage {
+  die <<"EOF"; 
+Usage: $0 [OPTIONS] [diff.tex] > revised.tex
+
+Read a file diff.tex (output of latexdiff), and remove its markup. 
+If no filename is given read from standard input. The command can be used
+in ACCEPT, DECLINE, or SIMPLIFY mode, and be used to remove user-defined
+latex commands from the input (see options -c, -e, -m, -n below). 
+In ACCEPT mode, all appended text fragments  (or preamble lines)
+are kept, and all discarded text fragments (or preamble lines) are
+deleted.  
+In DECLINE mode, all discarded text fragments are kept, and all appended 
+text fragments are deleted.  
+If you wish to keep some changes, edit the diff.tex file in
+advance, and manually remove those tokens  which would otherwise be
+deleted.  Note that latexrevise only pays attention to the \\DIFaddbegin,
+\\DIFaddend, \\DIFdelbegin, and \\DIFdelend tokens and corresponding FL
+varieties.  All \\DIFadd and \\DIFdel commands (but not their content) are 
+simply deleted.   The commands added by latexdiff to the preamble are also
+removed.
+In SIMPLIFY mode all latexdiff markup is removed from the body of the text (after
+\\begin{document}) except for \\DIFaddbegin, \\DIFaddend, \\DIFdelbegin, \\DIFdelend
+tokens and the corresponding FL varieties of those commands.  The result
+will not in general be valid latex-code but might be easier to read and edit in 
+preparation for a subsequent run in ACCEPT or DECLINE mode.  
+In SIMPLIFY mode the preamble is left unmodified.
+
+-a
+--accept          Run in ACCEPT mode (delete all blocks marked by \\DIFdelbegin
+                  and \\DIFdelend).
+
+-d
+--decline         Run in DECLINE mode (delete all blocks marked by \\DIFaddbegin
+                  and \\DIFaddend).
+
+-s
+--simplify        Run in SIMPLIFY mode (Keep all \\DIFaddbegin, \\DIFaddend, 
+                  \\DIFdelbegin, \\DIFdelend tokens, but remove all other latexdiff
+                  markup from body.  
+
+Note that the three mode options are mutually exclusive. If no mode option is given,
+latexrevise simply removes user annotations and markup according to the following four
+options.
+
+
+-c cmd
+--comment=cmd     Remove \\cmd{...}.  cmd is supposed to mark some explicit 
+                  anotations which should be removed from the file before 
+                  release.
+
+-e envir
+--comment-environment=envir 
+                  Remove explicit annotation environments from the text, i.e. remove
+                  \\begin{envir}
+                  ...
+                  \\end{envir}
+                  blocks.
+
+-m cmd
+--markup=cmd      Remove the markup command cmd but leave its argument, i.e.
+                  turn \\cmd{abc} into abc.  
+
+-n envir
+--markup-environment=envir  
+                  Similarly, remove \\begin{envir} and \\end{envir} commands,
+                  but leave content of the environment in the text.
+                  
+-q
+--no-warnings     Do not warn users about \\DIDadd{..} or \\DIFdel statements
+                  which should not be there anymore
+
+-V
+--verbose         Verbose output
+
+EOF
+}
+
+=head1 NAME
+
+latexrevise - selectively remove markup and text from latexdiff output
+
+=head1 SYNOPSIS
+
+B<latexrevise> [ B<OPTIONS> ] [ F<diff.tex> ] > F<revised.tex>
+
+=head1 DESCRIPTION
+
+I<latexrevise> reads a file C<diff.tex> (output of I<latexdiff>), and remove the markup commands. 
+If no filename is given the input is read from standard input. The command can be used
+in I<ACCEPT>, I<DECLINE>, or I<SIMPLIFY> mode, or can be used to remove user-defined
+latex commands from the input (see B<-c>, B<-e>, B<-m>, and B<-n> below). 
+In I<ACCEPT> mode, all appended text fragments  (or preamble lines)
+are kept, and all discarded text fragments (or preamble lines) are
+deleted.  
+In I<DECLINE> mode, all discarded text fragments are kept, and all appended 
+text fragments are deleted.  
+If you wish to keep some changes, edit the diff.tex file in
+advance, and manually remove those tokens  which would otherwise be
+deleted.  Note that I<latexrevise> only pays attention to the C<\DIFaddbegin>,
+C<\DIFaddend>, C<\DIFdelbegin>, and C<\DIFdelend> tokens and corresponding FL
+varieties.  All C<\DIFadd> and C<\DIFdel> commands (but not their contents) are 
+simply deleted.   The commands added by latexdiff to the preamble are also
+removed.
+In I<SIMPLIFY> mode, C<\DIFaddbegin, \DIFaddend, \DIFdelbegin, \DIFdelend>
+tokens and their corresponding C<FL> varieties are kept but all other markup (e.g. C<DIFadd> and <\DIFdel>) is removed.  The result
+will not in general be valid latex-code but it will be easier to read and edit in 
+preparation for a subsequent run in I<ACCEPT> or I<DECLINE> mode.  
+In I<SIMPLIFY> mode the preamble is left unmodified.
+
+=head1 OPTIONS
+
+=over 4
+
+=item B<-a> or B<--accept>
+
+Run in I<ACCEPT> mode (delete all blocks marked by C<\DIFdelbegin> and C<\DIFdelend>).
+
+=item B<-d> or B<--decline>
+
+Run in I<DECLINE> mode (delete all blocks marked by C<\DIFaddbegin>
+and C<\DIFaddend>).
+
+=item B<-s> or B<--simplify>
+
+Run in I<SIMPLIFY> mode (Keep all C<\DIFaddbegin>, C<\DIFaddend>, 
+C<\DIFdelbegin>, C<\DIFdelend> tokens, but remove all other latexdiff
+markup from body).  
+
+=back
+
+Note that the three mode options are mutually exclusive.  If no mode option is given,
+I<latexrevise> simply removes user annotations and markup according to the following four
+options.
+
+=over 4
+
+=item B<-c cmd> or B<--comment=cmd>
+
+Remove C<\cmd{...}> sequences.  C<cmd> is supposed to mark some explicit 
+anotations which should be removed from the file before 
+release.
+
+=item B<-e envir> or B<--comment-environment=envir> 
+
+Remove explicit annotation environments from the text, i.e. remove
+
+            \begin{envir}
+            ...
+            \end{envir}
+
+blocks.
+
+=item B<-m cmd> or B<--markup=cmd>
+
+Remove the markup command C<\cmd> but leave its argument, i.e.
+turn C<\cmd{abc}> into C<abc>.  
+
+=item B<-n envir> or B<--markup-environment=envir>
+
+Similarly, remove C<\begin{envir}> and C<\end{envir}> commands but 
+leave content of the environment in the text.
+                  
+
+=item B<-V> or B<--verbose>
+
+Verbose output
+
+=item B<-q> or B<--no-warnings>
+
+Do not warn users about C<\DIDadd{..}> or C<\DIFdel{..}> statements
+which should have been removed already.
+
+=back
+
+=head1 BUGS
+
+The current version is a beta version which has not yet been
+extensively tested, but worked fine locally.  Please send bug reports
+to I<tilmann@esc.cam.ac.uk>.  Include the serial number of I<latexrevise>
+(from comments at the top of the source).  If you come across latexdiff
+output which is not processed correctly by I<latexrevise> please include the
+problem file as well as the old and new files on which it is based,
+ideally edited to only contain the offending passage as long as that still
+reproduces the problem.
+
+I<latexrevise> gets confused by commented C<\begin{document}> or 
+C<\end{document}> statements
+
+=head1 SEE ALSO
+
+L<latexdiff>
+
+=head1 PORTABILITY
+
+I<latexrevise> does not make use of external commands and thus should run
+on any platform  supporting PERL v5 or higher. 
+
+=head1 AUTHOR
+
+Copyright (C) 2004 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+
+=cut
diff --git a/Master/bin/alpha-linux/latexdiff b/Master/bin/alpha-linux/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/alpha-linux/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/alpha-linux/latexdiff-vc b/Master/bin/alpha-linux/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/alpha-linux/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/alpha-linux/latexrevise b/Master/bin/alpha-linux/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/alpha-linux/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/i386-cygwin/latexdiff b/Master/bin/i386-cygwin/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/i386-cygwin/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/i386-cygwin/latexdiff-vc b/Master/bin/i386-cygwin/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/i386-cygwin/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/i386-cygwin/latexrevise b/Master/bin/i386-cygwin/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/i386-cygwin/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/i386-linux/latexdiff b/Master/bin/i386-linux/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/i386-linux/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/i386-linux/latexdiff-vc b/Master/bin/i386-linux/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/i386-linux/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/i386-linux/latexrevise b/Master/bin/i386-linux/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/i386-linux/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/i386-netbsd/latexdiff b/Master/bin/i386-netbsd/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/i386-netbsd/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/i386-netbsd/latexdiff-vc b/Master/bin/i386-netbsd/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/i386-netbsd/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/i386-netbsd/latexrevise b/Master/bin/i386-netbsd/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/i386-netbsd/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/i386-solaris/latexdiff b/Master/bin/i386-solaris/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/i386-solaris/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/i386-solaris/latexdiff-vc b/Master/bin/i386-solaris/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/i386-solaris/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/i386-solaris/latexrevise b/Master/bin/i386-solaris/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/i386-solaris/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/mips-irix/latexdiff b/Master/bin/mips-irix/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/mips-irix/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/mips-irix/latexdiff-vc b/Master/bin/mips-irix/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/mips-irix/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/mips-irix/latexrevise b/Master/bin/mips-irix/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/mips-irix/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/powerpc-aix/latexdiff b/Master/bin/powerpc-aix/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/powerpc-aix/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/powerpc-aix/latexdiff-vc b/Master/bin/powerpc-aix/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/powerpc-aix/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/powerpc-aix/latexrevise b/Master/bin/powerpc-aix/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/powerpc-aix/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/powerpc-linux/latexdiff b/Master/bin/powerpc-linux/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/powerpc-linux/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/powerpc-linux/latexdiff-vc b/Master/bin/powerpc-linux/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/powerpc-linux/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/powerpc-linux/latexrevise b/Master/bin/powerpc-linux/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/powerpc-linux/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/sparc-linux/latexdiff b/Master/bin/sparc-linux/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/sparc-linux/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/sparc-linux/latexdiff-vc b/Master/bin/sparc-linux/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/sparc-linux/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/sparc-linux/latexrevise b/Master/bin/sparc-linux/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/sparc-linux/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/sparc-solaris/latexdiff b/Master/bin/sparc-solaris/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/sparc-solaris/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/sparc-solaris/latexdiff-vc b/Master/bin/sparc-solaris/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/sparc-solaris/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/sparc-solaris/latexrevise b/Master/bin/sparc-solaris/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/sparc-solaris/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/universal-darwin/latexdiff b/Master/bin/universal-darwin/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/universal-darwin/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/universal-darwin/latexdiff-vc b/Master/bin/universal-darwin/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/universal-darwin/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/universal-darwin/latexrevise b/Master/bin/universal-darwin/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/universal-darwin/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/bin/x86_64-linux/latexdiff b/Master/bin/x86_64-linux/latexdiff
new file mode 120000
index 00000000000..8a08889cc78
--- /dev/null
+++ b/Master/bin/x86_64-linux/latexdiff
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff.pl
\ No newline at end of file
diff --git a/Master/bin/x86_64-linux/latexdiff-vc b/Master/bin/x86_64-linux/latexdiff-vc
new file mode 120000
index 00000000000..608d1da907e
--- /dev/null
+++ b/Master/bin/x86_64-linux/latexdiff-vc
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexdiff-vc
\ No newline at end of file
diff --git a/Master/bin/x86_64-linux/latexrevise b/Master/bin/x86_64-linux/latexrevise
new file mode 120000
index 00000000000..36bc5559964
--- /dev/null
+++ b/Master/bin/x86_64-linux/latexrevise
@@ -0,0 +1 @@
+../../texmf-dist/scripts/latexdiff/latexrevise
\ No newline at end of file
diff --git a/Master/texmf-dist/doc/latex/latexdiff/CHANGES b/Master/texmf-dist/doc/latex/latexdiff/CHANGES
new file mode 100644
index 00000000000..18853d35f76
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/CHANGES
@@ -0,0 +1,138 @@
+Version 0.5 
+===========
+
+- add \protect in front of all changebar package commands.  These prevents error messages
+  when changes are made to section titles in any styles making use of changebar package
+
+- For a changed section, the deletion is now reported before the insertion, in common
+  with standard practice for diff programs
+
+- "\begin{equation}%" and similar constructs no longer confuse latexdiff
+
+- deals correctly with some fairly pathological cases of math mode switching - code 
+  should parse but equation numbers and linebreaks might be changed
+
+- \\[..] is now left alone (previously, this got erroneously interpreted as \ \begin{displaymath})
+
+- \(..\) is recognised as a synonym for $...$
+
+- introduce new subclasses of textcmd
+   context1cmd  are text commands which should be disabled in a deleted block, as they
+                are only meaningful in certain contexts (e.g. \caption).  However, their
+                argument is still marked up as deleted (plain) text, surrounded by a pair of braces.
+   context2cmd  behave like text commands except that they are completely disabled in deleted blocks,
+                including their arguments.
+
+- array environments within in-lined maths are now underlined correctly
+
+- if endfloat package is inferred from preamble, then make sure \begin{figure} and \end{figure}
+  are always on a line by themselves, similarly for table enviroment
+
+- if hyperref package is used, make wrapper for \DIFadd and \DIFdel which protects markup from becoming 
+  part of link texts where it causes an error
+
+- if amsmath package is used, then default eqnarray environement (Variable MATHARRREPL) is set to align
+  (Default: eqnarray).  Also, the standard amsmath equation array environments are now recognised as such.
+
+- new option --packages
+
+Version 0.42 November 2006
+==========================
+
+- the auxiliary commands put in to bring latexdiff into and out of 
+  math mode correctly would sometimes not be consistent. This is no longer the 
+  case
+
+- If a comment was put between two commands within a deleted block, the 
+  latter command would not be disabled by a DIFDELCMD
+
+
+
+Version 0.4 January 2006
+========================
+
+- $$ $$ usually accepted for displayed equations (but less robust than \[ \] or displaymath environment)
+
+- For commands which are in textcmd list but not in safecmd list (e.g. \footnote and \section commands) the content is now marked up if they are added or deleted. (Thanks to S. Utcke for alerting me to this shortcoming of previous versions).  The downside of this change is that deleted section heads are now shown, messing up the section numbering
+
+- added RCS and SVN support to latexdiff-vc (previous name latexdiff-cvs)
+
+- a fast version (latexdiff-fast) uses the UNIX diff command to speed up the differencing phases.
+
+Minor bug fixes:
+
+- Improved parsing of textcmd and safecmd lists, some clarification in manual (Thanks to V. Kuhlmann for fix)
+
+- All \color commands now \protect'ed (V. Kuhlmann)
+
+- Picture environment within floats now is cleared up properly (Thanks to V. Kuhlmann for fix)
+
+- non-matching textcommands right before \end{document} are now parsed correctly
+
+- updates to textcmd (emph, text..) and safecmd lists (emph)
+
+- fixed \par bug.  Previously, this bug resulted new paragraphs to be merged with the following paragraph.
+
+- better error checking in latexdiff-vc
+
+- can specify arbitrary number of files in latexdiff-vc
+
+- can choose output directory in latexdiff-vc
+
+Version 0.3 August 2005
+==========================
+
+- fixed bug where a deleted displayed equation would result in math mode commands 
+  being processed in text mode (the "! Missing $ inserted" error). 
+ 
+- Improved parsing in math mode: Superscript and subscript and \left,\right are now parsed correctly
+
+- shell script for providing CVS support
+
+Minor:
+
+- fixed a bug in utf8 mode that resulted in many warning messages and
+  failure to parse properly words with national characters
+
+- Now works with the latest version of Algorithm::Diff (version 1.19)
+
+- new options "--allow-spaces" and "--ignore-warnings"
+
+- Better wording and enhanced context for warning messages 
+
+- '|' character is now recognised as valid math mode character
+
+- Fixed a bug whereby \begin{document} and \end{document} in comments are nevertheless treated as real begin and end points
+
+- add \protect in front of \nogroupcolor command in DVIPSCOL subtype (old version broke sometimes according to bug reports although I could not replicate the problem) 
+
+- replace \uline by \uwave in CUNDERLINE style, such that added and deleted text parts look different even in math mode
+
+- Markup within DIFnomarkup enviroment is removed by latexdiff. This can be used to protect parts
+  for which latexdiff has trouble creating proper latex code. 
+
+- new markup type FONTSTRIKE
+
+
+Version 0.2  September 2004
+===========================
+
+- introduced subtype DVIPSCOL (coloring changed blocks for dvips converter)
+
+- support for utf8 and other encodings 
+
+Minor:
+
+- removed buggy COLOR subtype
+
+- Usage information no longer printed automatically after certain syntactic error messages
+
+- short options -a, -A, -x, -X now really do what is claimed in the manual
+
+- bug in failback splitting of input was fixed
+
+- options --exclude-textcmd, --append-textcmd, --exclude-safecmd, and --append-safecmd
+  can now take comma-separated list as well as a file as argument.
+
+
+
diff --git a/Master/texmf-dist/doc/latex/latexdiff/LICENSE b/Master/texmf-dist/doc/latex/latexdiff/LICENSE
new file mode 100644
index 00000000000..960fe7469fe
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/LICENSE
@@ -0,0 +1,280 @@
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
diff --git a/Master/texmf-dist/doc/latex/latexdiff/Makefile b/Master/texmf-dist/doc/latex/latexdiff/Makefile
new file mode 100644
index 00000000000..45467307879
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/Makefile
@@ -0,0 +1,64 @@
+# Modify these paths to the requirements of your own system
+# For the current setting you will need root permission but 
+# it is perfectly acceptable to choose user directories 
+#
+INSTALLPATH = /usr/local
+INSTALLMANPATH = $(INSTALLPATH)/man
+INSTALLEXECPATH = $(INSTALLPATH)/bin
+
+default:
+	@echo "To install stand-alone version type:    make install"
+	@echo "  (Note the standard version requires prior installation"
+	@echo "   of the PERL package Algorithm::Diff available from "
+	@echo "   the PERL archive www.cpan.org)"
+	@echo " "
+	@echo "To install fast version (using UNIX diff) type: make install fast "
+	@echo " "
+	@echo "To install the version which uses the system Algorithm::Diff package type: make install-ext"
+	@echo " "
+
+install: install-so
+
+install-ext: install-latexdiff install-latexrevise install-latexdiff-vc install-man
+
+install-so: install-latexdiff-so install-latexrevise install-latexdiff-vc install-man
+
+install-fast: install-latexdiff-fast install-latexrevise install-latexdiff-vc install-man
+
+install-man:
+	install latexrevise.1 latexdiff.1 latexdiff-vc.1 $(INSTALLMANPATH)/man1
+
+install-latexdiff:
+	install latexdiff $(INSTALLEXECPATH)
+
+install-latexdiff-so:
+	if [ -e $(INSTALLEXECPATH)/latexdiff ]; then rm $(INSTALLEXECPATH)/latexdiff; fi
+	install latexdiff-so $(INSTALLEXECPATH)
+	cd $(INSTALLEXECPATH); ln -s latexdiff-so latexdiff
+
+install-latexdiff-fast:
+	if [ -e $(INSTALLEXECPATH)/latexdiff ]; then rm $(INSTALLEXECPATH)/latexdiff; fi
+	install latexdiff-fast $(INSTALLEXECPATH)
+	cd $(INSTALLEXECPATH); ln -s latexdiff-fast latexdiff
+
+install-latexrevise:
+	install latexrevise $(INSTALLEXECPATH)
+
+install-latexdiff-vc:
+	install latexdiff-vc $(INSTALLEXECPATH)
+	cd $(INSTALLEXECPATH); for vcs in cvs rcs svn ; do if [ -e latexdiff-$$vcs ]; then rm latexdiff-$$vcs; fi; ln -s latexdiff-vc latexdiff-$$vcs ; done
+
+test-ext: 
+	@echo "latexdiff example/example-draft.tex example/example-rev.tex (system Algorithm::Diff)"
+	./latexdiff -V example/example-draft.tex example/example-rev.tex > example/example-diff.tex
+	@echo "Difference file created: example/example-diff.tex"
+
+test-so: 
+	@echo "latexdiff example/example-draft.tex example/example-rev.tex (stand-alone version)"
+	./latexdiff-so -V example/example-draft.tex example/example-rev.tex > example/example-diff.tex
+	@echo "Difference file created: example/example-diff.tex"
+
+test-fast: 
+	@echo "latexdiff example/example-draft.tex example/example-rev.tex (stand-alone version)"
+	./latexdiff-fast -V example/example-draft.tex example/example-rev.tex > example/example-diff.tex
+	@echo "Difference file created: example/example-diff.tex"
diff --git a/Master/texmf-dist/doc/latex/latexdiff/README b/Master/texmf-dist/doc/latex/latexdiff/README
new file mode 100644
index 00000000000..78adffb533a
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/README
@@ -0,0 +1,98 @@
+
+INTRODUCTION
+
+latexdiff is a Perl script, which compares two latex files and marks
+up significant differences between them (i.e. a diff for latex files).
+  Various options are available for visual markup using standard latex 
+packages such as "color.sty". Changes not directly affecting visible 
+text, for example in formatting commands, are still marked in 
+the latex source.
+ 
+A rudimentary revision facilility is provided by another Perl script,
+latexrevise, which accepts or rejects all changes.  Manual
+editing of the difference file can be used to override this default
+behaviour and accept or reject selected changes only.  
+
+The author is F Tilmann.
+
+
+REQUIREMENTS
+
+Perl 5.8 or higher must be installed.
+  The latexdiff script makes use of the Perl package Algorithm::Diff (available 
+from www.cpan.org, current version 1.19). You can either install this package, or
+use the standalone version of latexdiff, latexdiff-so, which has version 1.15 of 
+this package inlined and does not require external installation of
+the package. Because latexdiff uses internal functions of Algorithm:Diff whose 
+calling format or availability can change without notice, the preferred method is
+now to use the standalone version.
+
+As an alternative, latexdiff-fast has a modified version of Algorithm::Diff inlined,
+which internally uses the UNIX diff command.  This version is much faster but is dependent
+on an external "diff" command.  Subtle differences in the algorithm of Algorithm::Diff and 
+UNIX-diff mean that the resulting set of differences will generally not be the same as
+for the standard latexdiff.  In most practical cases, these differences are minor, though.
+
+INSTALLATION UNIX/LINUX
+
+The basic installation procedure is almost trivial:
+
+1. Copy latexdiff, latexrevise and latexdiff-vc into a directory which
+   is in the search path and make them executable.  If the Algorithm::Diff
+   package is not installed, use latexdiff-so instead of latexdiff. 
+
+2. Copy latexdiff.1 and latexrevise.1 into the correct man directory
+
+3. Optionally create soft links latexdiff-cvs latexdiff-rcs, and
+   latexdiff-svn for latexdiff-vc.
+
+The attached Makefile contains example commands to carry out above 
+steps as root for a typical UNIX installation. Type 
+
+  make install          (for the stand alone version)
+or
+  make install-ext      (for the version using the external Algorithm::Diff)
+or
+  make install-fast     (for the version using the UNIX 'diff' function for fast differencing)
+
+to get it rolling.  You can type
+
+  make test
+or
+  make test-ext
+or
+  make test-fast
+
+to test the respective versions on a brief example before installation
+
+
+DOCUMENTATION:
+
+Usage instructions are in the manual latexdiff-man.pdf as well as the 
+man pages.
+
+CONTRIBUTIONS
+
+The directory contrib contains code written by others relating to latexdiff.  
+Currently this directory contains:
+
+latexdiff-wrap (Author: V. Kuhlmann) An alternative wrapper script which can be used
+  instead of latexdiff-vc.  Its main use is as a template for customised wrapper scripts.
+
+latexdiff.spec (Author: T. Doerges) spec file for RPM generation
+
+The following contributions were incorporated into the latexdiff code, or inspired me to 
+extend latexdiff in a similar way: J. Paisley, N. Becker, K. Huebner
+
+LICENSE
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2 as published by
+the Free Software Foundation.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details (file LICENSE in the
+distribution).
+
diff --git a/Master/texmf-dist/doc/latex/latexdiff/contrib/latexdiff-wrap b/Master/texmf-dist/doc/latex/latexdiff/contrib/latexdiff-wrap
new file mode 100755
index 00000000000..894b424de36
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/contrib/latexdiff-wrap
@@ -0,0 +1,192 @@
+#!/bin/bash
+#
+# latexdiff-wrap
+#
+# Wrapper for latexdiff, to
+#   * provide support for documents consiting of more than 1 latex file
+#   * provide my common arguments
+#
+# Copyright (C) by Volker Kuhlmann <VolkerKuhlmann@gmx.de>
+# Released under the terms of the GNU General Public License (GPL) Version 2.
+# See http://www.gnu.org/ for details.
+#
+# Volker Kuhlmann
+#   5, 6, 7, 12, 16, 17 Oct 2005
+#   31 Jan; 5, 7, 13, 15 Feb 2006
+#
+
+VERSION="0.6, 15 Feb 2006"
+AUTHOR="Volker Kuhlmann <VolkerKuhlmann@gmx.de>"
+COPYRIGHT="Copyright (C) 2005-2006"
+
+
+####
+#### Constants and initialised variables
+#
+diffcmd="latexdiff"
+diffrc="$HOME/texmf/latexdiff"
+#diffargs="-e latin1 --ignore-warnings -p latexdiff-preamble.sty"
+diffargs="-e latin1 --ignore-warnings"
+diffargs="$diffargs --append-safecmd $diffrc/safe-cmds"
+diffargs="$diffargs --append-textcmd $diffrc/text-cmds"
+# Note: Can't use multiple --append-safecmd
+# show current command lists:
+#diffcmd="$diffcmd --show-safecmd --show-textcmd --show-config"
+
+
+####
+#### Version, Usage, Help
+#
+show_version() {
+    echo "${0##*/} version $VERSION
+$COPYRIGHT by $AUTHOR"
+}
+
+show_usage() {
+    echo "
+Usage: ${0##*/} OLDDIR NEWDIR DIFFDIR [DIFFARGS --] FILE.tex [...]
+       ${0##*/} --show [DIFFARGS]
+Version $VERSION
+$COPYRIGHT by $AUTHOR
+"
+}
+
+show_help() {
+    show_usage
+    echo "\
+For each FILE.tex, build a new file DIFFDIR/FILE.tex with markup of the changes
+which were made from OLDDIR/FILE.tex to NEWDIR/FILE.tex.
+Any path given with FILE.tex is stripped off.
+Any DIFFARGS are added to the latexdiff call, if present (remember to follow
+them with a double-hyphen on its own before the FILE arguments).
+
+With --show, shows the settings latexdiff would be running with, including the
+changes applied by the user.
+"
+}
+
+# For scripts not using function library only:
+Version() { show_version; exitwith ErrVersion; }
+Usage() { show_help; exitwith ErrUsage; }
+Help() { test "$1" && exitwith ErrHelp show_help; show_help; exitwith ErrOK; }
+
+
+####
+#### Error/Exit codes
+#
+exitwith() {
+    exec 1>&2  # write stdout on stderr instead
+  case "$1" in
+    ErrOK)
+    	exit 0;;
+    ErrVersion|ErrUsage|ErrHelp)
+	# Output generated by function (program) $2, if given
+	test -n "$2" && "$2"
+	exit 1;;
+ # more codes in here
+ # more codes in here
+    ErrBadoption)
+    	echo "Bad option '$2'."
+	echo "Call with -h for help."
+	exit 9;;
+    ErrMissingParameter)
+	echo "A required parameter for option $2 is missing."
+	echo "Call with -h for help."
+	exit 9;;
+    *)
+	echo "Internal error: exitwith() called with illegal error code '$1'."
+	exit 19;;
+  esac
+}
+
+
+####
+#### Parse command line parameters
+#
+
+# If the next arg starts with a "-", collect additional argument for latexdiff
+# until "--".
+scanextraargs() {
+    addargs=()
+    case "$1" in -*)
+	while [ $# -gt 0 -a "$1" != "--" ]; do
+    	    addargs=( "${addargs[@]}" "$1" )
+	    shift
+	done
+	test "$1" == "--" && shift
+    ;; esac
+    fileargs=( "$@" )
+}
+
+case "$1" in
+    --version)	    	Version;;
+    --usage)	    	Usage;;
+    --help|-h|-help)	Help;;
+    --show)
+        shift
+	scanextraargs "$@"
+	(set -x
+	$diffcmd $diffargs "${addargs[@]}" \
+	    --show-safecmd --show-textcmd --show-config 
+	) | fmt
+    	exit $? ;;
+esac
+
+olddir="${1%/}"
+newdir="${2%/}"
+diffdir="${3%/}"
+
+if ! [ -d "$olddir" -a -d "$newdir" -a -d "$diffdir" ]; then
+    Help 1>&2 err
+fi
+
+shift 3
+
+scanextraargs "$@"
+set -- "${fileargs[@]}"
+
+
+
+####
+#### Functions
+#
+#set -x
+Log() { echo 1>&2 "+ $@"; "$@"; }
+
+
+####
+#### Main
+#
+
+# Create output directory, just in case.
+(set -x
+mkdir -p "$diffdir"
+)
+while [ $# -gt 0 ]; do
+    file="${1##*/}"
+    echo Examining: "$file"
+    # No point running latexdiff if both files are identical,
+    # but run latexdiff on top-level LaTeX file in any case.
+    if cmp --quiet "$olddir/$file" "$newdir/$file" \
+	&& ! grep -lq '\\begin.*{document}' "$newdir/$file"; then
+	(set -x
+	cp -p "$olddir/$file" "$diffdir"
+	)
+    else
+    	# Delete file, to make sure it's not clobbered by redirecting stdout
+	# in case it's a symlink to te original.
+	test -f "$diffdir/$file" && (set -x
+	rm "$diffdir/$file"
+	)
+	# Run latexdiff if both input files are present.
+	run=1
+	test -f "$olddir/$file" || { echo 1>&2 "No file: $olddir/$file"; run=; }
+	test -f "$newdir/$file" || { echo 1>&2 "No file: $newdir/$file"; run=; }
+	test -n "$run" && \
+	(set -x
+	$diffcmd $diffargs "${addargs[@]}" \
+	    "$olddir/$file" "$newdir/$file"  > "$diffdir/$file"
+	)
+    fi
+    shift
+done
diff --git a/Master/texmf-dist/doc/latex/latexdiff/contrib/latexdiff.spec b/Master/texmf-dist/doc/latex/latexdiff/contrib/latexdiff.spec
new file mode 100644
index 00000000000..9255a69fea9
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/contrib/latexdiff.spec
@@ -0,0 +1,58 @@
+Summary: Diff for LaTeX files
+Name: latexdiff
+Version: 0.5
+Release: 1
+License: GPL
+Group: Productivity/Publishing/TeX/Utilities
+URL: http://www.tug.org/tex-archive/help/Catalogue/entries/latexdiff.html
+Source0: %{name}.zip
+BuildArch: noarch
+BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
+# only required for 'make install-ext'
+# Requires: perl-Algorithm-Diff
+
+
+%description
+latexdiff is a Perl script, which compares two latex files and marks
+up significant differences between them (i.e. a diff for latex files).
+  Various options are available for visual markup using standard latex
+packages such as "color.sty". Changes not directly affecting visible
+text, for example in formatting commands, are still marked in
+the latex source.
+
+(C) 2004 Frederik Tilmann <tilmann@esc.cam.ac.uk>
+
+
+%prep
+%setup -n %{name}
+
+
+%build
+# quick had to adapt the Makefile
+%{__mv} Makefile Makefile.old
+%{__sed} \
+  -e "s;INSTALLPATH = /usr/local;INSTALLPATH = \${DESTDIR}%{_prefix};" \
+  -e "s;INSTALLMANPATH = \$(INSTALLPATH)/man;INSTALLMANPATH = \${DESTDIR}%{_mandir};" \
+  Makefile.old > Makefile
+
+
+%install
+%{__mkdir_p} $RPM_BUILD_ROOT%{_bindir}
+%{__mkdir_p} $RPM_BUILD_ROOT%{_mandir}/man1
+
+%makeinstall
+
+
+%clean
+[ "${RPM_BUILD_ROOT}" != "/" ] && [ -d "${RPM_BUILD_ROOT}" ] && %{__rm} -rf "${RPM_BUILD_ROOT}"
+
+
+%files
+%defattr(-,root,root)
+%doc example CHANGES LICENSE README
+%{_bindir}/*
+%{_mandir}/man*/*
+
+%changelog
+* Thu Jan  4 2007 Till Dörges <till@doerges.net> - 0.5-1
+- Initial build.
diff --git a/Master/texmf-dist/doc/latex/latexdiff/example/example-draft.tex b/Master/texmf-dist/doc/latex/latexdiff/example/example-draft.tex
new file mode 100644
index 00000000000..593a1707121
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/example/example-draft.tex
@@ -0,0 +1,59 @@
+\documentclass[12pt,a4paper]{article}
+
+\setlength{\topmargin}{-0.2in}
+\setlength{\textheight}{9.5in}
+\setlength{\oddsidemargin}{0.0in}
+
+\setlength{\textwidth}{6.5in}
+
+\title{latexdiff Example - Draft version}
+\author{F Tilmann}
+
+\begin{document}
+\maketitle
+
+\section*{Introduction}
+
+This is an extremely simple document that showcases some of latexdiff features.
+Type
+\begin{verbatim}
+latexdiff -t UNDERLINE example-draft.tex example-rev.tex > example-diff.tex
+\end{verbatim}
+to create the difference file.  You can inspect this file directly. Then run either 
+\begin{verbatim}
+pdflatex example-diff.tex
+xpdf example-diff.pdf
+\end{verbatim}
+or
+\begin{verbatim}
+latex example-diff.tex
+dvips -o example-diff.ps example-diff.dvi
+gv example-diff.ps
+\end{verbatim}
+to display the markup.
+
+\section*{Another section title}
+
+A paragraph with a line only in the draft document.  More things could be said 
+were it not for the constraints of time and space.
+
+More things could be said were it not for the constraints of time and space.
+
+And here is a tipo. 
+
+Here is a table:
+
+\begin{tabular}{ll}
+Name & Description \\
+\hline
+Gandalf & Grey \\
+Saruman & White
+\end{tabular}
+
+And sometimes a whole paragraph gets completely rewritten. In this
+case latexdiff marks up the whole paragraph even if some words in it
+are identical.
+No change, no markup!
+\end{document}
+
+
diff --git a/Master/texmf-dist/doc/latex/latexdiff/example/example-rev.tex b/Master/texmf-dist/doc/latex/latexdiff/example/example-rev.tex
new file mode 100644
index 00000000000..4bcaf156272
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/example/example-rev.tex
@@ -0,0 +1,60 @@
+\documentclass[12pt,a4paper]{article}
+
+\setlength{\topmargin}{-0.2in}
+\setlength{\textheight}{9.5in}
+\setlength{\oddsidemargin}{0.0in}
+
+\setlength{\textwidth}{6in}
+
+\title{latexdiff Example - Revised version}
+\author{F Tilmann}
+% Note how in the preamble visual markup is never used (even
+% if some preamble might eventually end up as visible text.)
+
+\begin{document}
+\maketitle
+
+\section*{Introduction}
+
+This is an extremely simple document that showcases some of the latexdiff features.
+Type
+\begin{verbatim}
+latexdiff -t UNDERLINE example-draft.tex example-rev.tex > example-diff.tex
+\end{verbatim}
+to create the difference file.  You can inspect this file directly. Then run either 
+\begin{verbatim}
+pdflatex example-diff.tex
+xpdf example-diff.pdf
+\end{verbatim}
+or
+\begin{verbatim}
+latex example-diff.tex
+dvips -o example-diff.ps example-diff.dvi
+gv example-diff.ps
+\end{verbatim}
+to display the markup.
+
+\section*{Yet another section title}
+
+ More things could be said were it not for the constraints of time and space.
+
+A paragraph with a line only in the revised document.  More things could be 
+said were it not for the constraints of time and space.
+
+And here is a typo. 
+
+Here is a table:
+
+\begin{tabular}{ll}
+Name & Description \\
+\hline
+Gandalf & White \\
+Saruman & Evil
+\end{tabular}
+
+And now for something completely different, with not a paragraph in sight.
+No change, 
+no markup!
+\end{document}
+
+
diff --git a/Master/texmf-dist/doc/latex/latexdiff/latexdiff b/Master/texmf-dist/doc/latex/latexdiff/latexdiff
new file mode 100755
index 00000000000..efceea4c2ee
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/latexdiff
@@ -0,0 +1,2783 @@
+#!/usr/bin/perl -w
+# latexdiff - differences two latex files on the word level
+#             and produces a latex file with the differences marked up.
+#
+#   Copyright (C) 2004-2007  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# Version 0.5  A number of minor improvements based on feedback
+#              Deleted blocks are now shown before added blocks
+#              Package specific processing
+#
+# Version 0.43 unreleased typo in list of styles at the end
+#              Add protect to all \cbstart, \cbend commands
+#              More robust substitution of deleted math commands
+#
+# Version 0.42 November 06  Bug fixes only
+#
+# Version 0.4   March 06 option for fast differencing using UNIX diff command, several minor bug fixes (\par bug, improved highlighting of textcmds)
+#
+# Version 0.3   August 05 improved parsing of displayed math, --allow-spaces 
+#               option, several minor bug fixes
+#
+# Version 0.25  October 04 Fix bug with deleted equations, add math mode commands to safecmd, add | to allowed interpunctuation signs
+# Version 0.2   September 04 extension to utf-8 and variable encodings
+# Version 0.1   August 04    First public release
+
+use Algorithm::Diff qw(traverse_sequences);
+
+use Getopt::Long ;
+use strict ;
+use utf8 ;
+
+my ($algodiffversion)=split(/ /,$Algorithm::Diff::VERSION);
+
+
+my ($versionstring)=<<EOF ;
+This is LATEXDIFF 0.5  (Algorithm::Diff $Algorithm::Diff::VERSION)
+  (c) 2004-2007 F J Tilmann
+EOF
+
+# Configuration variables: these have to be visible from the subroutines
+my $MINWORDSBLOCK=3; # minimum number of tokens to form an independent block
+                     # shorter identical blocks will be merged to the previous word
+my $FLOATENV='(?:figure|table|plate)[\w\d*@]*' ;   # Environments in which FL variants of defined commands are used
+my $PICTUREENV='(?:picture|DIFnomarkup)[\w\d*@]*' ;   # Environments in which all change markup is removed
+my $MATHENV='(?:equation|displaymath|DOLLARDOLLAR)' ;           # Environments turning on display math mode (code also knows about \[ and \]
+my $MATHREPL='displaymath';  # Environment introducing deleted maths blocks
+my $MATHARRENV='(?:eqnarray|align|gather|multiline|flalign)[*]?' ;           # Environments turning on eqnarray math mode
+my $MATHARRREPL='eqnarray*';  # Environment introducing deleted maths blocks
+my $ARRENV='(?:array|[pbvBV]matrix)'; # Enviroments making arrays in math mode.  The underlining style does not cope well with those - as a result in-text math environments are surrounded by \mbox{ } if any of these commands is used in an inline math block
+my $COUNTERCMD='(?:footnote|part|section|subsection|subsubsection|paragraph|subparagraph)';  # textcmds which are associated with a counter
+                                        # If any of these commands occur in a deleted block
+                                        # they will be succeeded by an \addtocounter{...}{-1}
+                                        # for the associated counter such that the overall numbers
+                                        # should be the same as in the new file
+
+# Markup strings
+# If at all possible, do not change these as parts of the program
+# depend on the actual name (particularly post-processing)
+# At the very least adapt subroutine postprocess to new tokens.
+my $ADDMARKOPEN='\DIFaddbegin ';   # Token to mark begin of appended text
+my $ADDMARKCLOSE='\DIFaddend ';   # Token to mark end of appended text
+my $ADDOPEN='\DIFadd{';  # To mark begin of added text passage
+my $ADDCLOSE='}';        # To mark end of added text passage
+my $ADDCOMMENT='DIF > ';   # To mark added comment line
+my $DELMARKOPEN='\DIFdelbegin ';   # Token to mark begin of deleted text
+my $DELMARKCLOSE='\DIFdelend ';   # Token to mark end of deleted text
+my $DELOPEN='\DIFdel{';  # To mark begin of deleted text passage
+my $DELCLOSE='}';        # To mark end of deleted text passage
+my $DELCMDOPEN='%DIFDELCMD < ';  # To mark begin of deleted commands (must begin with %, i.e., be a comment
+my $DELCMDCLOSE="%%%\n";    # To mark end of deleted commands (must end with a new line)
+my $AUXCMD='%DIFAUXCMD' ; #  follows auxiliary commands put in by latexdiff to make difference file legal
+                          # auxiliary commands must be on a line of their own
+my $DELCOMMENT='DIF < ';   # To mark deleted comment line
+
+
+# main local variables:
+my @TEXTCMDLIST=();  # array containing patterns of commands with text arguments
+my @TEXTCMDEXCL=();  # array containing patterns of commands without text arguments (if a pattern
+                     # matches both TEXTCMDLIST and TEXTCMDEXCL it is excluded)
+my @CONTEXT1CMDLIST=();  # array containing patterns of commands with text arguments (subset of text commands),
+                         # but which cause confusion if used out of context (e.g. \caption). 
+                         # In deleted passages, the command will be disabled but its argument is marked up
+                         # Otherwise they behave exactly like TEXTCMD's 
+my @CONTEXT1CMDEXCL=();  # exclude list for above, but always empty
+my @CONTEXT2CMDLIST=();  # array containing patterns of commands with text arguments, but which fail cause confusion
+                         # if used out of context (e.g. \title). They and their arguments will be disabled in deleted
+                         # passages
+my @CONTEXT2CMDEXCL=();  # exclude list for above, but always empty
+
+my @SAFECMDLIST=();  # array containing patterns of safe commands (which do not break when in the argument of DIFadd or DIFDEL)
+my @SAFECMDEXCL=();
+
+my ($i,$j,$l);
+my ($old,$new);
+my ($line);
+my ($newpreamble,$oldpreamble);
+my (@newpreamble,@oldpreamble,@diffpreamble,@diffbody);
+my ($latexdiffpreamble);
+my ($oldbody, $newbody, $diffbo);
+my ($oldpost, $newpost);
+my ($diffall);
+# Option names
+my ($type,$subtype,$floattype,$config,$preamblefile,$encoding,
+    $showpreamble,$showsafe,$showtext,$showconfig,$showall,
+    $replacesafe,$appendsafe,$excludesafe,
+    $replacetext,$appendtext,$excludetext,
+    $replacecontext1,$appendcontext1,
+    $replacecontext2,$appendcontext2,
+    $help,$verbose,$version,$ignorewarnings,$allowspaces,$flatten,$debug);
+my (@configlist,
+    @appendsafelist,@excludesafelist,
+    @appendtextlist,@excludetextlist,
+    @appendcontext1list,@appendcontext2list,
+    @packagelist);
+my ($assign,@config);
+# Hash where keys corresponds to the names of  all included packages (including the documentclass as another package
+# the optional arguments to the package are the values of the hash elements
+my ($pkg,%packages);
+# Defaults
+$type='UNDERLINE';
+$subtype='SAFE';
+$floattype='FLOATSAFE';
+
+$verbose=0;
+$debug=1; 
+# define character properties
+sub IsNonAsciiPunct { return <<'END'    # Unicode punctuation but excluding ASCII punctuation
++utf8::IsPunct
+-utf8::IsASCII
+END
+}
+sub IsNonAsciiS { return <<'END'       # Unicode symbol but excluding ASCII
++utf8::IsS
+-utf8::IsASCII
+END
+}
+
+
+
+  my %verbhash;
+
+Getopt::Long::Configure('bundling');
+GetOptions('type|t=s' => \$type, 
+	   'subtype|s=s' => \$subtype, 
+	   'floattype|f=s' => \$floattype, 
+	   'config|c=s' => \@configlist,
+	   'preamble|p=s' => \$preamblefile,
+	   'encoding|e=s' => \$encoding,
+	   'exclude-safecmd|A=s' => \@excludesafelist,
+	   'replace-safecmd=s' => \$replacesafe,
+	   'append-safecmd|a=s' => \@appendsafelist,
+	   'exclude-textcmd|X=s' => \@excludetextlist,
+	   'replace-textcmd=s' => \$replacetext,
+	   'append-textcmd|x=s' => \@appendtextlist,
+	   'replace-context1cmd=s' => \$replacecontext1,
+	   'append-context1cmd=s' => \@appendcontext1list,
+	   'replace-context2cmd=s' => \$replacecontext2,
+	   'append-context2cmd=s' => \@appendcontext2list,
+	   'show-preamble' => \$showpreamble,
+	   'show-safecmd' => \$showsafe,
+	   'show-textcmd' => \$showtext,
+	   'show-config' => \$showconfig,
+	   'show-all' => \$showall,
+           'packages=s' => \@packagelist,
+	   'verbose|V' => \$verbose,
+	   'ignore-warnings' => \$ignorewarnings,
+	   'allow-spaces' => \$allowspaces,
+	   'flatten' => \$flatten,
+	   'version' => \$version,
+	   'help|h|H' => \$help);
+
+if ( $help ) {
+  usage() ;
+}
+
+
+if ( $version ) {
+  die $versionstring ; 
+}
+
+print STDERR $versionstring if $verbose; 
+
+if (defined($showall)){
+  $showpreamble=$showsafe=$showtext=$showconfig=1;
+}
+
+# setting extra preamble commands
+if (defined($preamblefile)) {
+  $latexdiffpreamble=join "\n",(extrapream($preamblefile),"");
+} else {
+  $latexdiffpreamble=join "\n",(extrapream($type,$subtype,$floattype),"");
+}
+
+# setting up @SAFECMDLIST and @SAFECMDEXCL
+if (defined($replacesafe)) {
+  init_regex_arr_ext(\@SAFECMDLIST,$replacesafe);
+} else {
+  init_regex_arr_data(\@SAFECMDLIST, "SAFE COMMANDS");
+}
+foreach $appendsafe ( @appendsafelist ) {
+  init_regex_arr_ext(\@SAFECMDLIST, $appendsafe);
+}
+foreach $excludesafe ( @excludesafelist ) {
+  init_regex_arr_ext(\@SAFECMDEXCL, $excludesafe);
+}
+
+# Special: treat all cite commands as safe except in UNDERLINE and FONTSTRIKE mode
+# (there is a conflict between citation and ulem package, see
+# package documentation)
+if ( uc($type) ne "UNDERLINE" && uc($type) ne "FONTSTRIKE" && uc($type) ne "CULINECHBAR" ) {
+  push (@SAFECMDLIST, qr/^cite.*$/);
+}
+
+# setting up @TEXTCMDLIST and @TEXTCMDEXCL
+if (defined($replacetext)) {
+  init_regex_arr_ext(\@TEXTCMDLIST,$replacetext);
+} else {
+  init_regex_arr_data(\@TEXTCMDLIST, "TEXT COMMANDS");
+}
+foreach $appendtext ( @appendtextlist ) {
+  init_regex_arr_ext(\@TEXTCMDLIST, $appendtext);
+}
+foreach $excludetext ( @excludetextlist ) {
+  init_regex_arr_ext(\@TEXTCMDEXCL, $excludetext);
+}
+
+
+# setting up @CONTEXT1CMDLIST ( @CONTEXT1CMDEXCL exist but is always empty )
+if (defined($replacecontext1)) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST,$replacecontext1);
+} else {
+  init_regex_arr_data(\@CONTEXT1CMDLIST, "CONTEXT1 COMMANDS");
+}
+foreach $appendcontext1 ( @appendcontext1list ) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST, $appendcontext1);
+}
+
+
+# setting up @CONTEXT2CMDLIST ( @CONTEXT2CMDEXCL exist but is always empty )
+if (defined($replacecontext2)) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST,$replacecontext2);
+} else {
+  init_regex_arr_data(\@CONTEXT2CMDLIST, "CONTEXT2 COMMANDS");
+}
+foreach $appendcontext2 ( @appendcontext2list ) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST, $appendcontext2);
+}
+
+
+
+
+# setting configuration variables
+@config=();
+foreach $config ( @configlist ) {
+  if (-f $config ) {
+    open(FILE,$config) or die ("Couldn't open configuration file $config: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@config,$_);
+    }
+    close(FILE);
+  }
+  else {
+#    foreach ( split(",",$config) ) {
+#      push @config,$_;
+#    }
+     push @config,split(",",$config)
+  }
+}
+foreach $assign ( @config ) {
+  $assign=~ m/\s*(\w*)\s*=\s*(\S*)\s*$/ or die "Illegal assignment $assign in configuration list (must be variable=value)";  
+  if ( $1 eq "MINWORDSBLOCK" ) { $MINWORDSBLOCK = $2; }
+  elsif ( $1 eq "FLOATENV" ) { $FLOATENV = $2 ; }
+  elsif ( $1 eq "PICTUREENV" ) { $PICTUREENV = $2 ; }
+  elsif ( $1 eq "MATHENV" ) { $MATHENV = $2 ; }
+  elsif ( $1 eq "MATHREPL" ) { $MATHREPL = $2 ; }
+  elsif ( $1 eq "MATHARRENV" ) { $MATHARRENV = $2 ; }
+  elsif ( $1 eq "MATHARRREPL" ) { $MATHARRREPL = $2 ; }
+  elsif ( $1 eq "ARRENV" ) { $ARRENV = $2 ; }
+  elsif ( $1 eq "COUNTERCMD" ) { $COUNTERCMD = $2 ; }
+  else { die "Unknown variable $1 in assignment.";}
+}
+
+
+foreach $pkg ( @packagelist ) {
+  map { $packages{$_}="" } split(/,/,$pkg) ;
+}
+
+if ($showpreamble) {
+  print "\nPreamble commands:\n";
+  print $latexdiffpreamble ;
+}
+
+if ($showsafe) {
+  print "\nCommands safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE (unless excluded):\n";
+  print_regex_arr(@SAFECMDLIST);
+  print "\nCommands not safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE :\n";
+  print_regex_arr(@SAFECMDEXCL);
+}
+
+if ($showtext) {
+  print "\nCommands with last argument textual (unless excluded) and safe in every context:\n";
+  print_regex_arr(@TEXTCMDLIST);
+  print "\nContext1 commands (last argument textual, command will be disabled in deleted passages, last argument will be shown as plain text):\n";
+  print_regex_arr(@CONTEXT1CMDLIST);
+  print "\nContext2 commands (last argument textual, command ant its argument will be disabled in deleted passages):\n";
+  print_regex_arr(@CONTEXT2CMDLIST);  
+  print "\nExclude list of Commands with last argument not textual (overrides patterns above):\n";
+  print_regex_arr(@TEXTCMDEXCL);
+}
+
+if ($showconfig) {
+  print "Configuration variables:\n";
+  print "MINWORDSBLOCK=$MINWORDSBLOCK\n";
+  print "FLOATENV=$FLOATENV\n";
+  print "PICTUREENV=$PICTUREENV\n";
+  print "MATHENV=$MATHENV\n";
+  print "MATHREPL=$MATHREPL\n";
+  print "MATHARRENV=$MATHARRENV\n";
+  print "MATHARRREPL=$MATHARRREPL\n";
+  print "ARRENV=$ARRENV\n";
+  print "COUNTERCMD=$COUNTERCMD\n";
+}
+if ($showconfig || $showtext || $showsafe || $showpreamble) {
+  exit 0; }
+if ( @ARGV != 2 ) { 
+  print STDERR "2 and only 2 non-option arguments required.  Write latexdiff -h to get help\n";
+  exit(2);
+}
+
+# Are extra spaces between command arguments permissible?
+my $extraspace;
+if ($allowspaces) {
+  $extraspace='\s*'; 
+} else {
+  $extraspace='';
+}
+
+# append context lists to text lists (as text property is implied)
+push @TEXTCMDLIST, @CONTEXT1CMDLIST;
+push @TEXTCMDLIST, @CONTEXT2CMDLIST;
+
+
+# Patterns. These are used by some of the subroutines, too
+# I can only define them down here because value of extraspace depends on an option
+  my $pat0 = '(?:[^{}]|\\\{|\\\})*';
+  my $pat1 = '(?:[^{}]|\\\{|\\\}|\{'.$pat0.'\})*';
+  my $pat2 = '(?:[^{}]|\\\{|\\\}|\{'.$pat1.'\})*'; # 
+  my $pat3 = '(?:[^{}]|\\\{|\\\}|\{'.$pat2.'\})*';
+  my $pat4 = '(?:[^{}]|\\\{|\\\}|\{'.$pat3.'\})*';
+  my $brat0 = '(?:[^\[\]]|\\\[|\\\])*'; 
+
+  my $quotemarks = '(?:\'\')|(?:\`\`)';
+  my $punct='[0.,\/\'\`:;\"\?\(\)\[\]!~\p{IsNonAsciiPunct}\p{IsNonAsciiS}]';
+  my $number='-?\d*\.\d*';
+  my $mathpunct='[+=<>\-\|]';
+  my $and = '&';
+  my $coords= '[\-.,\s\d]*';
+# word: sequence of letters or accents followed by letter
+  my $word='(?:[-\w\d*]|\\\\[\"\'\`~^][A-Za-z\*])+';
+  my $cmdleftright='\\\\(?:left|right)\s*(?:[()\[\]|]|\\\\(?:[|{}]|\w+))';
+
+  my $cmdoptseq='\\\\[\w\d\*]+'.$extraspace.'(?:(?:\['.$brat0.'\]|\{'. $pat4 . '\}|\(' . $coords .'\))'.$extraspace.')*';
+  my $oneletcmd='\\\\.(?:\['.$brat0.'\]|\{'. $pat4 . '\})*';
+  my $math='\$(?:[^$]|\\\$)*?\$|\\\\[(].*?\\\\[)]';
+#  my $math='\$(?:[^$]|\\\$)*\$';
+  my $comment='%.*?\n';
+  my $pat=qr/(?:\A\s*)?(?:${and}|${quotemarks}|${number}|${word}|$cmdleftright|${cmdoptseq}|${math}|${oneletcmd}|${comment}|${punct}|${mathpunct}|\{|\})\s*/ ;
+
+
+
+# now we are done setting up and can start working   
+my ($oldfile, $newfile) = @ARGV;
+
+$encoding=guess_encoding($newfile) unless defined($encoding);
+
+$encoding = "utf8" if $encoding =~ m/^utf8/i ;
+if (lc($encoding) eq "utf8" ) {
+  binmode(STDOUT, ":utf8");
+  binmode(STDERR, ":utf8");
+}
+
+$old=read_file_with_encoding($oldfile,$encoding);
+$new=read_file_with_encoding($newfile,$encoding);
+
+
+
+
+# reset time
+exetime(1);
+($oldpreamble,$oldbody,$oldpost)=splitdoc($old,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+($newpreamble,$newbody,$newpost)=splitdoc($new,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+if ($flatten) {
+  $oldbody=flatten($oldbody,$oldpreamble,$oldfile,$encoding);
+  $newbody=flatten($newbody,$newpreamble,$newfile,$encoding);
+}
+
+if ( length $oldpreamble && length $newpreamble ) {
+  @oldpreamble = split /\n/, $oldpreamble;
+  @newpreamble = split /\n/, $newpreamble;
+  
+  %packages=list_packages(@newpreamble) unless %packages;
+  if (defined $packages{"hyperref"} ) {
+    print STDERR "hyperref package detected.\n" if $verbose ;
+    $latexdiffpreamble =~ s/\{\\DIFadd\}/{\\DIFaddtex}/g;
+    $latexdiffpreamble =~ s/\{\\DIFdel\}/{\\DIFdeltex}/g;
+    $latexdiffpreamble .= join "\n",(extrapream("HYPERREF"),"");
+  }
+  # insert dummy first line such that line count begins with line 1 (rather than perl's line 0) - just so that line numbers inserted by linediff are correct
+  unshift @newpreamble,'';
+  unshift @oldpreamble,'';
+  print STDERR "Differencing preamble.\n" if $verbose;
+  @diffpreamble = linediff(\@oldpreamble, \@newpreamble);
+  # remove dummy line again
+  shift @diffpreamble; 
+  push @diffpreamble,$latexdiffpreamble;
+  push @diffpreamble,'\begin{document}';
+}
+elsif ( !length $oldpreamble && !length $newpreamble ) {
+  @diffpreamble=();
+} else {
+  print STDERR "Either both texts must have preamble or neither text must have the preamble.\n";
+  exit(2);
+}
+
+if (defined $packages{"amsmath"} ) {
+  print STDERR "amsmath package detected.\n" if $verbose ;
+  $MATHARRREPL='align*';
+}
+
+print STDERR "Preprocessing body.  " if $verbose;
+my ($oldleadin,$newleadin)=preprocess($oldbody,$newbody);
+
+
+# run difference algorithm
+@diffbody=bodydiff($oldbody, $newbody);
+$diffbo=join("",@diffbody);
+print STDERR "(",exetime()," s)\n","Postprocessing body. \n " if $verbose;
+postprocess($diffbo);
+$diffall =join("\n",@diffpreamble) ;
+$diffall .= "$newleadin$diffbo" ;
+$diffall .= "\\end{document}$newpost" if length $newpreamble ;
+if ( lc($encoding) ne "utf8" && lc($encoding) ne "ascii" ) {
+  print STDERR "Encoding output file to $encoding\n" if $verbose;
+  $diffall=Encode::encode($encoding,$diffall);
+  binmode STDOUT;
+}
+print $diffall;
+
+
+print STDERR "(",exetime()," s)\n","Done.\n" if $verbose;
+
+
+
+## guess_encoding(filename)
+## reads the first 20 lines of filename and looks for call of inputenc package
+## if found, return the option of this package (encoding), otherwise return ascii
+sub guess_encoding {
+  my ($filename)=@_;
+  my ($i,$enc);
+  open (FH, $filename) or die("Couldn't open $filename: $!");
+  $i=0;
+  while (<FH>) {
+    next if /^\s*%/;    # skip comment lines
+    if (m/\\usepackage\[(\w*?)\]\{inputenc\}/) {
+      close(FH);
+      return($1);
+    }
+    last if (++$i > 20 ); # scan at most 20 non-comment lines
+  }
+  close(FH);
+  return("ascii");
+}
+
+
+sub read_file_with_encoding {
+  my ($output);
+  my ($filename, $encoding) = @_;
+
+  if (lc($encoding) eq "utf8" ) {
+    open (FILE, "<:utf8",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } elsif ( lc($encoding) eq "ascii") {
+    open (FILE, $filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } else {
+    require Encode;
+    open (FILE, "<",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+    print STDERR "Converting $filename from $encoding to utf8\n" if $verbose;
+    $output=Encode::decode($encoding,$output);
+  }
+  close FILE;
+  return $output;
+}
+
+# %packages=list_packages(@preamble)
+# scans the arguments for \documentclass and \usepackage statements and constructs a hash
+# whose keys are the included packages, and whose values are the associated optional arguments
+sub list_packages {
+  my (@preamble)=@_;
+  my %packages=();
+  foreach $line ( @preamble ) {
+    # get rid of comments
+    $line=~s/(?<!\\)%.*$// ;
+    if ( $line =~ m/\\(?:documentclass|usepackage)(?:\[(.+?)\])?\{(.*?)\}/ ) {
+#      print STDERR "Found something: |$line|\n";
+      if (defined($1)) {
+	$packages{$2}=$1;
+      } else {
+	$packages{$2}="";
+      }
+    }
+  }
+  return (%packages);
+}
+
+# flatten($text,$preamble,$filename,$encoding)
+# expands \input and \include commands within text
+# premable is scanned for includeonly commands
+# encoding is the encoding
+sub flatten {
+  my ($text,$preamble,$filename,$encoding)=@_;
+  my ($includeonly,$dirname,$fname,$newpage,$replacement);
+  require File::Basename ; 
+  require File::Spec ; 
+  $dirname = File::Basename::dirname($filename);
+
+  if ( ($includeonly) = ($preamble =~ m/\\includeonly{(.*?)}/ ) ) {
+    $includeonly =~ s/,/|/g;
+  } else {
+    $includeonly = '.*?';
+  }
+
+  print STDERR "DEBUG: includeonly $includeonly\n";
+
+  $text=~s/\\input{(.*?)}|\\include{(${includeonly}(?:\.tex)?)}/{ 
+	    $fname = $1 if defined($1)  ;
+	    $fname = $2 if defined($2) ;       
+            #      # add tex extension unless there is a three letter extension already 
+            $fname .= ".tex" unless $fname =~ m|\.\w{3}|;
+            print STDERR "Include file $fname\n" if $verbose;
+            print STDERR "DEBUG looking for file ",File::Spec->catfile($dirname,$fname), "\n";
+            # content of file becomes replacement value, add \newpage if the command was include
+            $replacement=read_file_with_encoding(File::Spec->catfile($dirname,$fname), $encoding) or die
+                "Couldn't find file ",File::Spec->catfile($dirname,$fname),": $!";
+	    $newpage=(defined($2)? " \\newpage " : "") ;
+	    "$newpage$replacement$newpage";
+          }/exg;
+
+  return($text);
+}
+
+
+# print_regex_arr(@arr)
+# prints regex array without x-ism expansion put in by pearl to stdout
+sub print_regex_arr {
+  my $dumstring;
+  $dumstring = join(" ",@_);     # PERL generates string (?-xism:^ref$) for quoted refex ^ref$
+  $dumstring =~ s/\(\?-xism:\^(.*?)\$\)/$1/g;   # remove string and ^,$ marks before output
+  print $dumstring,"\n";
+}
+
+
+# @lines=extrapream($type)
+# reads line from appendix (end of file after __END__ token)
+sub extrapream {
+  my $type;
+  my @retval=("%DIF PREAMBLE EXTENSION ADDED BY LATEXDIFF") ;
+  my ($copy);
+
+  while (@_) {
+    $copy=0;
+    $type=shift ;
+    if ( -f $type ) {
+      open (FILE,$type) or die "Cannot open preamble file $type: $!";
+      print STDERR "Reading preamble file $type\n" if $verbose ;
+      while (<FILE>) {
+	chomp ;
+	if ( $_ =~ m/%DIF PREAMBLE/ ) {
+	  push (@retval,"$_"); 
+	} else {
+	  push (@retval,"$_ %DIF PREAMBLE"); 
+	}
+      }
+    } 
+    else {    # not (-f $type)
+      $type=uc($type);   # upcase argument
+      print STDERR "Preamble Internal Type $type\n" if $verbose;
+      while (<DATA>) {
+	if ( m/^%DIF $type/ ) {
+	  $copy=1; }
+	elsif ( m/^%DIF END $type/ ) {
+	  last; }
+	chomp;
+	push (@retval,"$_ %DIF PREAMBLE") if $copy;
+      }
+      if ( $copy == 0 ) {
+	print STDERR "\nPreamble style $type not implemented.\n";
+        print STDERR "Write latexdiff -h to get help with available styles\n";
+        exit(2);
+      }
+      seek DATA,0,0;    # rewind DATA handle to file begin
+    }
+  }
+  push (@retval,"%DIF END PREAMBLE EXTENSION ADDED BY LATEXDIFF")  ;
+  return @retval;
+}
+
+
+# ($part1,$part2,$part3)=splitdoc($text,$word1,$word2)
+# splits $text into 3 parts at $word1 and $word2.
+# if neither $word1 nor $word2 exist, $part1 and $part3 are empty, $part2 is $text
+# If only $word1 or $word2 exist but not the other, output an error message.
+
+# NB this version avoids $` and $' for performance reason although it only makes a tiny difference
+# (in one test gain a tenth of a second for a 30s run)
+sub splitdoc {
+  my ($text,$word1,$word2)=@_;
+  my ($part1,$part2,$part3)=("","","");
+  my ($rest,$pos);
+
+  if ( $text =~ m/(^[^%]*)($word1)/mg ) {
+    $pos=pos $text;
+    $part1=substr($text,0,$pos-length($2));
+    $rest=substr($text,$pos);
+    if ( $rest =~ m/(^[^%]*)($word2)/mg ) {
+      $pos=pos $rest;
+      $part2=substr($rest,0,$pos-length($2));
+      $part3=substr($rest,$pos);
+    } 
+    else {
+      die "$word1 and $word2 not in the correct order or not present as a pair." ;
+    }
+  } else {
+    $part2=$text;
+    die "$word2 present but not $word1." if ( $text =~ m/(^[^%]*)$word2/ms );
+  }
+  return ($part1,$part2,$part3);
+}
+
+
+
+
+
+# bodydiff($old,$new)
+sub bodydiff {
+  my ($oldwords, $newwords) = @_;
+  my @retwords;
+
+  print STDERR "(",exetime()," s)\n","Splitting into latex tokens \n" if $verbose;
+  print STDERR "Parsing $oldfile \n" if $verbose;
+  my @oldwords = splitlatex($oldwords);
+  print STDERR "Parsing $newfile \n" if $verbose;
+  my @newwords = splitlatex($newwords);
+  my $token;
+
+  print STDERR "(",exetime()," s)\n","Pass 1: Expanding text commands and merging isolated identities with changed blocks  " if $verbose;
+  pass1(\@oldwords, \@newwords);
+
+
+  print STDERR "(",exetime()," s)\n","Pass 2: inserting DIF tokens and mark up.  " if $verbose;
+
+  @retwords=pass2(\@oldwords, \@newwords);
+
+  return(@retwords);
+}
+
+
+
+
+# @words=splitlatex($string)
+# split string according to latex rules
+# Each element of words is either
+# a word (including trailing spaces and punctuation)
+# a latex command
+sub splitlatex {
+  my ($string) = @_ ;
+  my @retval=($string =~ m/$pat/osg);  
+
+  if (length($string) != length(join("",@retval))) {
+    print STDERR "\nWARNING: Inconsistency in length of input string and parsed string:\n     This often indicates faulty or non-standard latex code.\n     In many cases you can ignore this and the following warning messages.\n Note that character numbers in the following are counted beginning after \\begin{document} and are only approximate." unless $ignorewarnings;
+    print STDERR "DEBUG Original length ",length($string),"  Parsed length ",length(join("",@retval)),"\n" if $debug;
+    print STDERR "DEBUG Input string:  |$string|\n" if (length($string)<500) && $debug;
+    print STDERR "DEBUG Token parsing: |",join("+",@retval),"|\n" if (length($string)<500) && $debug ;
+    @retval=();
+    # slow way only do this if other m//sg method fails
+    my $last = 0;
+    while ( $string =~ m/$pat/osg ) {
+      my $match=$&;
+      if ($last + length $& != pos $string  ) {
+	my $pos=pos($string);
+	my $offset=30<$last ? 30 : $last;
+	my $dum=substr($string,$last-$offset,$pos-$last+2*$offset);
+	my $dum1=$dum;
+	my $cnt=$#retval;
+	my $i;
+	$dum1 =~ s/\n/ /g;
+	unless ($ignorewarnings) {
+	  print STDERR "\n$dum1\n";
+	  print STDERR " " x 30,"^" x ($pos-$last)," " x 30,"\n";
+	  print STDERR "Missing characters near word " . (scalar @retval) . " character index: " . $last . "-" .  pos($string) . " Length: " . length($match) . " Match: |$match| (expected match marked above).\n";
+	}
+	  # put in missing characters `by hand'
+	push (@retval, substr($dum,$offset,$pos-$last-length($match)));
+#       Note: there seems to be a bug in substr with utf8 that made the following line output substr which were too long,
+#             using dum instead appears to work
+#	push (@retval, substr($string,$last, pos($string)-$last-length($match)));
+      }
+      push (@retval, $match);
+      $last=pos $string;
+    }
+
+  }
+  return @retval;
+}
+
+
+# pass1( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.
+# Where an common-subsequence block is flanked by deleted or appended blocks, 
+# and is shorter than $MINWORDSBLOCK words it is appended
+# to the last deleted or appended word.  If the block contains tokens other than words 
+# or punctuation it is not merged.
+# Deleted or appended block consisting of words and safe commands only are
+# also merged, to prevent break-up in pass2 (after previous isolated words have been removed)
+# If there are commands with textual arguments (e.g. \caption) both in corresponding 
+# appended and deleted blocks split them such that the command and opening bracket 
+# are one token, then the rest is split up following standard rules, and the closing 
+# bracket is a separate token, ie. turn
+# "\caption{This is a textual argument}" into 
+# ("\caption{","This ","is ","a ","textual ","argument","}")
+# No return value.  Destructively changes sequences
+sub pass1 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $len1 = scalar @$seq1;
+  my $len2 = scalar @$seq2;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;   #'
+
+  my ($last1,$last2)=(-1,-1) ;
+  my $cnt=0;
+  my $block=[];
+  my $addblock=[];
+  my $delblock=[];
+  my $todo=[];
+  my $instruction=[];
+  my $i;
+  my (@delmid,@addmid,@dummy);
+
+  my ($addcmds,$delcmds,$matchindex);
+  my ($addtextblocks,$deltextblocks);
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $adddiscard = sub {
+                      if ($cnt > 0 ) {
+			$matblkcnt++;
+			# just after an unchanged block 
+#			print STDERR "Unchanged block $cnt, $last1,$last2 \n";
+                        if ($cnt < $MINWORDSBLOCK 
+			    && $cnt==scalar (
+				     grep { /^$wpat/ || ( /^\\([\w\d\*]+)((?:\[$brat0\]|\{$pat4\})*)/o 
+							   && iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+							   && scalar(@dummy=split(" ",$2))<3 ) }
+					     @$block) )  {
+			  # merge identical blocks shorter than $MINWORDSBLOCK 
+			  # and only containing ordinary words
+			  # with preceding different word
+			  # We cannot carry out this merging immediately as this
+			  # would change the index numbers of seq1 and seq2 and confuse
+			  # the algorithm, instead we store in @$todo where we have to merge
+                          push(@$todo, [ $last1,$last2,$cnt,@$block ]);
+			}
+			$block = []; 
+			$cnt=0; $last1=-1; $last2=-1;
+		      }
+		    };
+  my $discard=sub { $deltokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$delblock,[ $seq1->[$_[0]],$_[0] ]);
+		    $last1=$_[0] };		      
+
+  my $add =   sub { $addtokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$addblock,[ $seq2->[$_[1]],$_[1] ]);
+		    $last2=$_[1] };		      
+
+  my $match = sub { $mattokcnt++;
+                    if ($cnt==0) {   # first word of matching sequence after changed sequence or at beginning of word sequence
+		      $deltextblocks = extracttextblocks($delblock); 
+		      $delblkcnt++ if scalar @$delblock;
+		      $addtextblocks = extracttextblocks($addblock);
+		      $addblkcnt++ if scalar @$addblock;
+
+		      $delcmds = extractcommands($delblock);
+      		      $addcmds = extractcommands($addblock);
+		      # keygen(third argument of _longestCommonSubsequence) implies to sort on command (0th elements of $addcmd elements)
+		      # the calling format for longestCommonSubsequence has changed between versions of
+		      # Algorithm::Diff so we need to check which one we are using
+		      if ( $algodiffversion  > 1.15 ) {
+			### Algorithm::Diff 1.19
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, 0, sub { $_[0]->[0] } );
+		      } else {
+			### Algorithm::Diff 1.15	
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, sub { $_[0]->[0] } );
+		      }
+
+		      for ($i=0 ; $i<=$#$matchindex ; $i++) {
+			if (defined($matchindex->[$i])){
+			  $j=$matchindex->[$i];
+			  @delmid=splitlatex($delcmds->[$i][3]);
+			  @addmid=splitlatex($addcmds->[$j][3]);
+			  while (scalar(@$deltextblocks)  && $deltextblocks->[0][0]<$delcmds->[$i][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$deltextblocks) };
+			    push(@$todo, [$index,-1,$cnt,@$block]);
+			  }
+			  push(@$todo, [ $delcmds->[$i][1],-1,-1,$delcmds->[$i][2],@delmid,$delcmds->[$i][4]]);
+
+			  while (scalar(@$addtextblocks) && $addtextblocks->[0][0]<$addcmds->[$j][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			    push(@$todo, [-1,$index,$cnt,@$block]);
+			  }
+			  push(@$todo, [ -1,$addcmds->[$j][1],-1,$addcmds->[$j][2],@addmid,$addcmds->[$j][4]]);
+			}
+		      }
+		      # mop up remaining textblocks
+		      while (scalar(@$deltextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$deltextblocks) } ;
+			push(@$todo, [$index,-1,$cnt,@$block]);
+		      }
+		      while (scalar(@$addtextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			push(@$todo, [-1,$index,$cnt,@$block]);
+		      }
+		      
+		      $addblock=[];
+		      $delblock=[];
+		    }
+		    push(@$block,$seq2->[$_[1]]);  
+		    $cnt++  };
+
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+
+
+  # now carry out the merging/splitting.  Refer to elements relative from 
+  # the end (with negative indices) as these offsets don't change before the instruction is executed
+  # cnt>0: merged small unchanged groups with previous changed blocks
+  # cnt==-1: split textual commands into components
+  foreach $instruction ( @$todo) {
+    ($last1,$last2,$cnt,@$block)=@$instruction ;
+    if ($cnt>=0) {
+      splice(@$seq1,$last1-$len1,1+$cnt,join("",$seq1->[$last1-$len1],@$block)) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1+$cnt,join("",$seq2->[$last2-$len2],@$block)) if $last2>=0;
+    } else {
+      splice(@$seq1,$last1-$len1,1,@$block) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1,@$block) if $last2>=0;
+    }
+  }
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens in $matblkcnt blocks.\n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+}
+
+
+# extracttextblocks(\@blockindex)
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [[ $index, $textblock, $cnt ], ..
+# where $index index of block to be merged
+#       $textblock contains all the words to be merged with the word at $index (but does not contain this word)
+#       $cnt   is length of block
+#
+# requires: iscmd
+#
+sub extracttextblocks { 
+  my $block=shift;
+  my ($i,$token,$index);
+  my $textblock=[];
+  my $last=-1;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;  #'
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # store pure text blocks
+    if ($token =~ /$wpat/ ||  ( $token =~/^\\([\w\d\*]+)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*)/o 
+				&& iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+				&& !iscmd($1,\@TEXTCMDLIST,\@TEXTCMDEXCL))) {
+      # we have text or a command which can be treated as text
+      if ($last<0) {
+	# new pure-text block
+	$last=$index;
+      } else {
+	# add to pure-text block
+	push(@$textblock, $token); 
+      }
+    } else {
+      # it is not text
+      if (scalar(@$textblock)) {
+	push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+      }
+      $textblock=[];
+      $last=-1;
+    }
+  }
+  # finish processing a possibly unfinished block before returning
+  if (scalar(@$textblock)) {
+    push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+  }
+  return($retval)
+}
+
+
+
+# extractcommands( \@blockindex )
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [ [ "\cmd1", index, "\cmd1[optarg]{arg1}{", "arg2" ,"} " ],.. 
+# where index is just taken from input array 
+# command must have a textual argument as last argument 
+# 
+# requires: iscmd 
+# 
+sub extractcommands { 
+  my $block=shift;
+  my ($i,$token,$index,$cmd,$open,$mid,$closing);
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # check if token is an alphanumeric command sequence with at least one non-optional argument
+    # \cmd[...]{...}{last argument}  
+    # Capturing in the following results in these associations
+    # $1: \cmd[...]{...}{
+    # $2: \cmd
+    # $3: last argument
+    # $4: }  + trailing spaces
+    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	 && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL) ) {
+      #      push(@$retval,[ $2,$index,$1,$3,$4 ]);
+      ($cmd,$open,$mid,$closing) = ($2,$1,$3,$4) ;
+      $closing =~ s/\}/\\RIGHTBRACE/ ;
+      push(@$retval,[ $cmd,$index,$open,$mid,$closing ]);
+    }
+  }
+  return $retval;
+}
+
+# iscmd($cmd,\@regexarray,\@regexexcl) checks
+# return 1 if $cmd matches any of the patterns in the 
+# array $@regexarray, and none of the patterns in \@regexexcl, otherwise return 0
+sub iscmd {
+  my ($cmd,$regexar,$regexexcl)=@_;
+  my ($ret)=0;
+  foreach $pat ( @$regexar ) {
+    if ( $cmd =~ m/^${pat}$/ ) {
+      $ret=1 ; 
+      last;
+    }
+  }
+  return 0 unless $ret;
+  foreach $pat ( @$regexexcl ) {
+    return 0 if ( $cmd =~ m/^${pat}$/ );
+  }
+  return 1;
+}
+
+
+# pass2( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.  
+# Mark begin and end of deleted and appended sequences with tags $DELOPEN and $DELCLOSE
+# and $ADDOPEN and $ADDCLOSE, respectively, however exclude { } & and all comands, unless
+# they match an element of the whitelist (SAFECMD)
+# For words in TEXTCMD but not in SAFECMD, enclose interior with $ADDOPEN and $ADDCLOSE brackets
+# Deleted comment lines are marked with %DIF < 
+# Added comment lines are marked with %DIF > 
+sub pass2 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $retval = [];
+  my $delhunk   = [];
+  my $addhunk   = [];
+
+  my $discard = sub { $deltokcnt++;
+                      push ( @$delhunk, $seq1->[$_[0]]) };
+
+  my $add = sub { $addtokcnt++;
+                  push ( @$addhunk, $seq2->[$_[1]]) };
+
+  my $match = sub { $mattokcnt++;
+		    if ( scalar @$delhunk ) {
+                      $delblkcnt++;
+		      # mark up changes, but comment out commands
+                      push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk);
+		      $delhunk = [];
+		    }
+                    if ( scalar @$addhunk ) {
+                      $addblkcnt++;
+                      # we mark up changes, but simply quote commands
+                      push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk);
+		      $addhunk = [];
+		    }
+		    push(@$retval,$seq2->[$_[1]]) };
+ 
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  # clear up unprocessed hunks
+  push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk) if scalar @$delhunk;
+  push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk) if scalar @$addhunk;
+
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens. \n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+
+  return(@$retval);
+}
+
+# marktags($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,\@block)
+# returns ($openmark,$open,$block,$close,$closemark) if @block only contains no commands (except white-listed ones),
+# braces, ampersands, or comments
+# mark comments with $comment
+# exclude all other exceptions from scope of open, close like this
+# ($openmark, $open,...,$close, $opencomd,command, command,$closecmd, $open, ..., $close, $closemark)
+# If $opencmd begins with "%" marktags assumes it is operating on a deleted block, otherwise on an added block
+sub marktags {
+  my ($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,$block)=@_;
+  my $word;
+  my (@argtext);
+  my $retval=[];
+  my $noncomment=0;
+  my $cmd=-1;    # -1 at beginning 0: last token written is a ordinary word 
+                 # 1: last token written is a command
+                # for keeping track whether we are just in a command sequence or in a word sequence
+  my $cmdcomment= ($opencmd =~ m/^%/);  # Flag to indicate whether opencmd is a comment (i.e. if we intend to simply comment out changed commands)
+  my ($command,$commandword,$closingbracket) ; # temporary variables needed below to remember sub-pattern matches
+
+# split this block to flatten out sequences joined in pass1
+  @$block=splitlatex(join "",@$block);
+  foreach (@$block) {
+    $word=$_; 
+    if ( $word =~ s/^%/%$comment/ ) {
+      # a comment
+      if ($cmd==1) {
+	push (@$retval,$closecmd) ;
+	$cmd=-1;
+      }
+      push (@$retval,$word); 
+      next;
+    }
+    if (! $noncomment) {
+      push (@$retval,$openmark); 
+      $noncomment=1;
+    }
+    # negative lookahead pattern (?!) in second clause is put in to avoid mathcing \( .. \) patterns
+    if ( $word =~ /^[&{}\[\]]/ || ( $word =~ /^\\(?!\()([\w*@]*)/ && !iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL)) ) {
+      # word is a command or other significant token (not in SAFECMDLIST)
+	## same conditions as in subroutine extractcommand:
+	# check if token is an alphanumeric command sequence with at least one non-optional argument
+	# \cmd[...]{...}{last argument}  
+	# Capturing in the following results in these associations
+	# $1: \cmd[...]{...}{
+	# $2: \cmd
+	# $3: last argument
+	# $4: }  + trailing spaces
+	### pre-0.3    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:\[$brat0\]|\{$pat4\})*\{)($pat4)(\}\s*)$/so )
+      if ( ( $word =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	   && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL)  && ( !$cmdcomment || !iscmd($2,\@CONTEXT2CMDLIST, \@CONTEXT2CMDEXCL) )  ) {	 
+	# word is a text command - we mark up the interior of the word. But if we are in a deleted block ($cmdcomment=1) and
+        # $2 (the command) is in context2, just treat it as an ordinary command (i.e. comment it open with $opencmd)
+        # Because we do not want to disable this command
+	# here we do not use $opencmd and $closecmd($opencmd is empty) 
+	if ($cmd==1) {
+	  push (@$retval,$closecmd) ;
+	} elsif ($cmd==0) { 
+	  push (@$retval,$close) ;
+	}
+        $command=$1; $commandword=$2; $closingbracket=$4;
+	@argtext=splitlatex($3);   # split textual argument into tokens
+	# and mark it up (but we do not need openmark and closemark)
+        # insert command with initial arguments, marked-up final argument, and closing bracket
+	if ( $cmdcomment && iscmd($commandword,\@CONTEXT1CMDLIST, \@CONTEXT1CMDEXCL) ) {
+	  # context1cmd in a deleted environment; delete command itself but keep last argument, marked up
+	  push (@$retval,$opencmd);
+	  $command =~ s/\n/\n${opencmd}/sg ; # repeat opencmd at the beginning of each line
+	  # argument, note that the additional comment character is included
+          # to suppress linebreak after opening parentheses, which is important
+          # for latexrevise
+          push (@$retval,$command,"%\n{$AUXCMD\n",marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);
+	} else {
+	  # normal textcmd or context1cmd in an added block
+	  push (@$retval,$command,marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);  
+	}
+	push (@$retval,$AUXCMD,"\n") if $cmdcomment ;
+	$cmd=-1 ;
+      } else {
+	# ordinary command
+	push (@$retval,$opencmd) if $cmd==-1 ;
+	push (@$retval,$close,$opencmd) if $cmd==0 ;
+	$word =~ s/\n/\n${opencmd}/sg if $cmdcomment ;   # if opencmd is a comment, repeat this at the beginning of every line
+	push (@$retval,$word);
+	$cmd=1;
+      }
+    } else {
+      # just an ordinary word or word in SAFECMD
+      push (@$retval,$open) if $cmd==-1 ;
+      push (@$retval,$closecmd,$open) if $cmd==1 ;
+      push (@$retval,$word);
+      $cmd=0;
+    }
+  }
+  push (@$retval,$close) if $cmd==0;
+  push (@$retval,$closecmd) if $cmd==1;
+
+  push (@$retval,$closemark) if ($noncomment);
+  return @$retval;
+}
+
+# preprocess($string, ..)
+# carry out the following pre-processing steps for all arguments:
+# 1. Remove leading white-space
+# 2. mark all first empty line (in block of several) with \PAR tokens
+# 3. Convert all '\%' into '\PERCENTAGE ' to make parsing regular expressions easier
+# 4. Convert all \verb|some verbatim text| commands (where | can be an arbitrary character)
+#    into \verb{hash}
+# 5. Convert \begin{verbatim} some verbatim text \end{verbatim} into \verbatim{hash}
+# 6. Convert _n into \SUBSCRIPTNB{n} and _{nnn} into \SUBSCRIPT{nn}
+# 7. Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+# 8. a. Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+#    b. Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+
+# 9. Add final token STOP to the very end.  This is put in because the algorithm works better if the last token is identical.  This is removed again in postprocessing.
+#
+# NB: step 6 and 7 is likely to  convert some "_" inappropriately, e.g. in file
+#     names or labels but it does not matter because they are converted back in the postprocessing step
+# Returns: leading white space removed in step 1
+sub preprocess {
+  my @leadin=() ;
+  for (@_) { 
+    s/^(\s*)//s;
+    push(@leadin,$1);
+    s/\n(\s*?)\n((?:\s*\n)*)/\n$1\\PAR\n$2/g ;
+    s/(?<!\\)\\%/\\PERCENTAGE /g ;  # (?<! is negative lookbehind assertion to prevent \\% from being converted
+    s/(\\verb\*?)(\S)(.*?)\2/"${1}{". tohash(\%verbhash,"${2}${3}${2}") ."}"/esg;
+    s/\\begin\{(verbatim\*?)\}(.*?)\\end\{\1\}/"\\${1}{". tohash(\%verbhash,"${2}") . "}"/esg;
+    # Convert _n or _\cmd into \SUBSCRIPTNB{n} or \SUBSCRIPTNB{\cmd} and _{nnn} into \SUBSCRIPT{nn}
+    s/_([^{\\]|\\\w+)/\\SUBSCRIPTNB{$1}/g ;
+    s/_{($pat4)}/\\SUBSCRIPT{$1}/g ;
+    # Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+    s/\^([^{\\]|\\\w+)/\\SUPERSCRIPTNB{$1}/g ;
+    s/\^{($pat4)}/\\SUPERSCRIPT{$1}/g ;
+    # Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+    s/\$\$(.*?)\$\$/\\begin{DOLLARDOLLAR}$1\\end{DOLLARDOLLAR}/sg;
+    # Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+    s/(?<!\\)\\\[/\\begin{SQUAREBRACKET}/sg;
+    s/\\\]/\\end{SQUAREBRACKET}/sg;
+    # add final token " STOP"
+    $_ .= " STOP"
+  }
+  return(@leadin);
+}
+
+#hashstring=tohash(\%hash,$string)
+# creates a hash value based on string and stores in %hash
+sub tohash {
+  my ($hash,$string)=@_;
+  my (@arr,$val);
+  my ($sum,$i)=(0,1);
+  my ($hstr);
+
+  @arr=unpack('c*',$string);
+
+  foreach $val (@arr) {
+    $sum += $i*$val;
+    $i++;
+  }
+  $hstr= "$sum";
+  if (defined($hash->{$hstr}) && $string ne $hash->{$hstr}) {
+    warn "Repeated hash value for verbatim mode in spite of different content.";
+    $hstr="-$hstr";
+  }
+  $hash->{$hstr}=$string;
+  return($hstr);
+}
+
+#string=fromhash(\%hash,$fromstring)
+# restores string value stored in hash
+#string=fromhash(\%hash,$fromstring,$prependstring)
+# additionally begins each line with prependstring
+sub fromhash {
+  my ($hash,$hstr)=($_[0],$_[1]);
+  my $retstr=$hash->{$hstr};
+  if ( $#_ >= 2) {
+    $retstr =~ s/^/$_[2]/mg;
+  }
+  return $retstr;
+}
+
+
+# postprocess($string, ..)
+# carry out the following post-processing steps for all arguments:
+# * Remove STOP token from the end
+# * Replace \RIGHTBRACE by }
+# 1. Check all deleted blocks: 
+#    a.where a deleted block contains a matching \begin and
+#      \end environment (these will be disabled by a %DIFDELCMD statements), for selected environment enable enable
+#      these commands again (such that for example displayed math in a deleted equation
+#      is properly within math mode.  For math mode environments replace numbered equation
+#      environments with their display only variety (so that equation numbers in new file and
+#      diff file are identical).  Where the correct type of math environment cannot be determined
+#      use a place holder MATHMODE
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+#    Replace all MATHMODE environment commands by the correct environment to achieve matching
+#    pairs
+#    c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+# 2. Remove DIFadd, DIFdel, DIFFaddbegin , ... from picture environments
+# 3. Convert DIFadd, DIFdel, DIFFaddbegin , ... into FL varieties
+#    within floats (currently recognised float environments: plate,table,figure
+#    plus starred varieties).
+# 4. Remove empty %DIFDELCMD < lines 
+# 4. Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+#    Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+# 6. Convert  \SUBSCRIPTNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+# 7. Expand hashes of verb and verbatim environments
+# 8. Convert '\PERCENTAGE ' back into '\%'
+# 9.. remove all \PAR tokens
+# 10.  package specific processing:  endfloat: make sure \begin{figure} and \end{figure} are always
+#      on a line by themselves, similarly for table environment
+#  4, undo renaming of the \begin and \end in comments
+
+#
+# Note have to manually synchronize substitution commands below and 
+# DIF.. command names in the header
+sub postprocess {
+  my ($begin,$len,$cnt,$float,$delblock,$addblock);
+  # second level blocks
+  my ($begin2,$cnt2,$len2,$eqarrayblock,$mathblock);
+
+  for (@_) { 
+
+    # change $'s in comments to something harmless
+    1 while s/(%.*)\$/$1DOLLARDIF/mg ;
+
+    # Remove final STOP token
+    s/ STOP$//;
+    # Replace \RIGHTBRACE by }    
+    s/\\RIGHTBRACE/}/g;
+    # Check all deleted blocks: where a deleted block contains a matching \begin and
+    #    \end environment (these will be disabled by a %DIFDELCMD statements), enable
+    #    these commands again (such that for example displayed math in a deleted equation
+    #    is properly within math mode.  For math mode environments replace numbered equation
+    #    environments with their display only variety (so that equation numbers in new file and
+    #    diff file are identical
+    while ( m/\\DIFdelbegin.*?\\DIFdelend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $delblock=$&;
+
+
+      ### (.*?[^\n]?)\n? construct is necessary to avoid empty lines in math mode, which result in
+      ### an error
+      # displayed math environments
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHREPL}$AUXCMD\n$1$3\n\\end{$MATHREPL}$AUXCMD\n$4/sg;
+      # also transform the opposite pair \end{displaymath} .. \begin{displaymath} but we have to be careful not to interfere with the results of the transformation in the line directly above
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHENV}; if found add \begin{$MATHREPL} and insert \end{$MATHREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+
+      # equation array environment
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHARRREPL}$AUXCMD\n$1$3\n\\end{$MATHARRREPL}$AUXCMD\n$4/sg;
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHARRENV}; if found add \begin{$MATHARRREPL} and insert \end{$MATHARRREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHARRREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHARRREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+      # parse $delblock for deleted and reinstated eqnarray* environments - within those reinstate \\ and & commands
+      while ( $delblock =~ m/\\begin\Q{$MATHARRREPL}$AUXCMD\E\n.*?\n\\end\Q{$MATHARRREPL}$AUXCMD\E\n/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$eqarrayblock=$&;
+	# reinstate deleted & and \\ commands
+	$eqarrayblock=~ s/(\%DIFDELCMD < \s*(\&|\\\\)\s*?(?:$DELCMDCLOSE|\n))/$1$2$AUXCMD\n/sg ;
+
+	substr($delblock,$begin2,$len2)=$eqarrayblock;
+	pos($delblock) = $begin2 + length($eqarrayblock);
+      }
+
+
+
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+      $delblock=~ s/\\($COUNTERCMD)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*\s*${AUXCMD}\n)/\\$1$2\\addtocounter{$1}{-1}${AUXCMD}\n/sg ;
+#     c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+      while ( $delblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($delblock,$begin2,$len2)=$mathblock;
+	pos($delblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified delblock
+      substr($_,$begin,$len)=$delblock;
+      pos = $begin + length($delblock);
+    }
+    # make the array modification in added blocks
+    while ( m/\\DIFaddbegin.*?\\DIFaddend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $addblock=$&;
+      while ( $addblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($addblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($addblock,$begin2,$len2)=$mathblock;
+	pos($addblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified addblock
+      substr($_,$begin,$len)=$addblock;
+      pos = $begin + length($addblock);
+    }
+
+
+    ### old place for BEGINDIF, ENDDIF replacement
+    # change begin and end commands  within comments such that they
+    # don't disturb the pattern matching (if there are several \begin or \end in one line
+    # this substitution is insufficient but that appears unlikely)
+    s/(%.*)\\begin\{(.*)$/$1\\BEGINDIF\{$2/mg ;
+    s/(%.*)\\end\{(.*)$/$1\\ENDDIF\{$2/mg ;
+
+    # Replace MATHMODE environments from step 1a above by the correct Math environment
+
+    # The next line is complicated.  The negative look-ahead insertion makes sure that no \end{$MATHENV} (or other mathematical
+    # environments) are between the \begin{$MATHENV} and \end{MATHMODE} commands. This is necessary as the minimal matching 
+    # is not globally minimal but only 'locally' (matching is beginning from the left side of the string)
+    1 while s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}((?:.(?!(?:\\end{(?:(?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}|\\begin{MATHMODE})))*?)\\end{MATHMODE}/\\begin{$1}$2\\end{$1}/s;
+    1 while s/\\begin{MATHMODE}((?:.(?!\\end{MATHMODE}))*?)\\end{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}/\\begin{$2}$1\\end{$2}/s;
+    # convert remaining \begin{MATHMODE} \end{MATHMODE} (and not containing & or \\ )into MATHREPL environments
+    s/\\begin{MATHMODE}((?:(.(?!(?<!\\)\&|\\\\))*)?)\\end{MATHMODE}/\\begin{$MATHREPL}$1\\end{$MATHREPL}/sg;
+    # others into MATHARRREPL
+    s/\\begin{MATHMODE}(.*?)\\end{MATHMODE}/\\begin{$MATHARRREPL}$1\\end{$MATHARRREPL}/sg;
+
+    # now look for AUXCMD math-mode pairs which have only comments (or empty lines between them), and remove the added commands
+    s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}$AUXCMD\n((?:\s*%.[^\n]*\n)*)\\end{\1}$AUXCMD\n/$2/sg; 
+
+
+    # Remove all mark up within picture environments
+    while ( m/\\begin\{($PICTUREENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin //g;
+      $float =~ s/\\DIFaddend //g;
+      $float =~ s/\\DIFadd\{($pat4)\}/$1/g;
+      $float =~ s/\\DIFdelbegin //g;
+      $float =~ s/\\DIFdelend //g;
+      $float =~ s/\\DIFdel\{($pat4)\}//g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    # Convert DIFadd, DIFdel, DIFFaddbegin , ... into  varieties
+    #    within floats (currently recognised float environments: plate,table,figure
+    #    plus starred varieties).
+    while ( m/\\begin\{($FLOATENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin /\\DIFaddbeginFL /g;
+      $float =~ s/\\DIFaddend /\\DIFaddendFL /g;
+      $float =~ s/\\DIFadd\{/\\DIFaddFL{/g;
+      $float =~ s/\\DIFdelbegin /\\DIFdelbeginFL /g;
+      $float =~ s/\\DIFdelend /\\DIFdelendFL /g;
+      $float =~ s/\\DIFdel\{/\\DIFdelFL{/g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    ### former location of undo renaming of \begin and \end in comments
+
+    # remove empty DIFCMD < lines
+    s/^\Q${DELCMDOPEN}\E\n//msg;
+
+    # Expand hashes of verb and verbatim environments (note negative look behind assertion to not leak out of DIFDELCMD comments
+    s/(\\verb\*?)\{([-\d]*?)\}/"${1}". fromhash(\%verbhash,$2)/esg;
+    s/${DELCMDOPEN}\\(verbatim\*?)\{([-\d]*?)\}/"${DELCMDOPEN}\\begin{${1}}".fromhash(\%verbhash,$2,$DELCMDOPEN)."${DELCMDOPEN}\\end{${1}}"/esg;
+    s/\\(verbatim\*?)\{([-\d]*?)\}/"\\begin{${1}}".fromhash(\%verbhash,$2)."\\end{${1}}"/esg;
+    # Convert '\PERCENTAGE ' back into '\%'			       
+    s/\\PERCENTAGE /\\%/g;
+    # remove all \PAR tokens (taking care to properly keep commented out PAR's
+    # from introducing uncommented newlines - next line)
+    s/(%DIF < )([^\n]*?)\\PAR\n/$1$2\n$1\n/sg;
+    # convert PAR commands which are on a line by themselves
+    s/\n(\s*?)\\PAR\n/\n\n/sg;
+    # convert remaining PAR commands (which are preceded by non-white space characters, usually "}" ($ADDCLOSE)
+    s/\\PAR\n/\n\n/sg;
+
+    #  package specific processing: 
+    if ( defined($packages{"endfloat"})) {
+      #endfloat: make sure \begin{figure} and \end{figure} are always
+      #      on a line by themselves, similarly for table environment
+      print STDERR "endfloat package detected.\n" if $verbose ;
+      # eliminate whitespace before and after
+      s/^(\s*)(\\(?:begin|end)\{(?:figure|table)\})(\s*)$/$2/mg;
+      # split lines with remaining characters before float enviroment conmmand
+      s/^(.+)(\\(?:begin|end)\{(?:figure|table)\})/$1\n$2/mg;
+      # split lines with remaining characters after float enviroment conmmand
+      s/(\\(?:begin|end)\{(?:figure|table)\})(.+)$/$1\n$2/mg;
+    }
+    # undo renaming of the \begin and \end  and dollars in comments 
+    s/(%.*)\\BEGINDIF\{(.*)$/$1\\begin\{$2/mg ;
+    s/(%.*)\\ENDDIF\{(.*)$/$1\\end\{$2/mg ;
+    1 while s/(%.*)DOLLARDIF/$1\$/mg ;
+#   Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+    s/\\end{SQUAREBRACKET}/\\\]/sg;
+    s/\\begin{SQUAREBRACKET}/\\\[/sg;
+# 4. Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+    s/\\begin\{DOLLARDOLLAR\}(.*?)\\end\{DOLLARDOLLAR\}/\$\$$1\$\$/sg;
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+    s/\\SUPERSCRIPTNB{($pat0)}/^$1/g ;
+    s/\\SUPERSCRIPT{($pat4)}/^{$1}/g ;
+    # Convert  \SUBSCRIPNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+    s/\\SUBSCRIPTNB{($pat0)}/_$1/g ;
+    s/\\SUBSCRIPT{($pat4)}/_{$1}/g ;
+
+  return;
+  }
+}
+
+
+# @diffs=linediff(\@seq1, \@seq2)
+# mark up lines like this
+#%DIF mm-mmdnn
+#%< old deleted line(s)
+#%DIF -------
+#%DIF mmann-nn
+#new appended line %< 
+#%DIF -------
+# Future extension: mark change explicitly
+# Assumes: traverse_sequence traverses deletions before insertions in changed sequences
+#          all line numbers relative to line 0 (first line of real file)
+sub linediff {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $block = [];
+  my $retseq = [];
+  my @begin=('','',''); # dummy initialisation
+  my $instring ; 
+
+  my $discard = sub { @begin=('d',$_[0],$_[1]) unless scalar @$block ; 
+                      push(@$block, "%DIF < " . $seq1->[$_[0]]) };
+  my $add = sub { if (! scalar  @$block) {
+		    @begin=('a',$_[0],$_[1]) ;}
+		  elsif ( $begin[0] eq 'd' ) {
+                    $begin[0]='c'; $begin[2]=$_[1];
+		    push(@$block, "%DIF -------") }
+                  push(@$block,  $seq2->[$_[1]] . " %DIF > " ) };
+  my $match = sub { if ( scalar @$block ) {
+                      if ( $begin[0] eq 'd' && $begin[1]!=$_[0]-1) {
+			$instring = sprintf "%%DIF %d-%dd%d",$begin[1],$_[0]-1,$begin[2]; }
+		      elsif ( $begin[0] eq 'a' && $begin[2]!=$_[1]-1) {
+			$instring = sprintf "%%DIF %da%d-%d",$begin[1],$begin[2],$_[1]-1; }
+		      elsif ( $begin[0] eq 'c' ) {
+			$instring = sprintf "%%DIF %sc%s",
+			                     ($begin[1]==$_[0]-1) ? "$begin[1]" : $begin[1]."-".($_[0]-1)  , 
+			                     ($begin[2]==$_[1]-1) ? "$begin[2]" : $begin[2]."-".($_[1]-1)  ; }
+		      else {
+			$instring = sprintf "%%DIF %d%s%d",$begin[1],$begin[0],$begin[2]; }
+		      push @$retseq, $instring,@$block, "%DIF -------" ; 
+		      $block = []; 
+		    }
+		    push @$retseq, $seq2->[$_[1]]
+		  };
+  # key function: remove multiple spaces (such that insertion or deletion of redundant white space is not reported)
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  push @$retseq, @$block if scalar @$block; 
+
+  return wantarray ? @$retseq : $retseq ;
+}
+
+
+
+# init_regex_arr_data(\@array,"TOKEN INIT")
+# scans DATA file handel for line "%% TOKEN INIT" line
+# then appends each line not beginning with % into array (as a quoted regex)
+sub init_regex_arr_data {
+  my ($arr,$token)=@_;
+  my ($copy);
+  while (<DATA>) {
+    if ( m/^%%BEGIN $token\s*$/ ) {
+      $copy=1; }
+    elsif ( m/^%%END $token\s*/ )  {
+      last; }
+    chomp;
+    push (@$arr,qr/^$_$/) if ( $copy && !/^%/ ) ;
+  }
+  seek DATA,0,0;    # rewind DATA handle to file begin
+}
+
+
+# init_regex_arr_ext(\@array,$arg)
+# fills array with regular expressions.
+# if arg is a file name, then read in list of regular expressions from that file
+# (one expression per line)
+# Otherwise treat arg as a comma separated list of regular expressions
+sub init_regex_arr_ext {
+  my ($arr,$arg)=@_;
+  my $regex;
+  if ( -f $ arg ) {
+    open(FILE,"$arg") or die ("Couldn't open $arg: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@$arr,qr/^$_$/);
+    }
+    close(FILE);
+  }
+  else {
+    # assume it is a comma-separated list of reg-ex
+    foreach $regex (split(qr/(?<!\\),/,$arg)) {
+      $regex =~ s/\\,/,/g;
+      push (@$arr,qr/^$regex$/);
+    }
+  }
+}
+
+#exetime() returns time since last execution of this command
+#exetime(1) resets this time
+my $lasttime=-1;   # global variable for persistence
+sub exetime {
+  my $reset=0;
+  my $retval;
+  if ((scalar @_) >=1) {
+    $reset=shift;
+  }
+  if ($reset) {
+    $lasttime=times();
+  }
+  else {
+    $retval=times()-$lasttime;
+    $lasttime=$lasttime+$retval;
+    return($retval);
+  }
+}
+
+
+sub usage {
+  die <<"EOF"; 
+Usage: $0 [options] old.tex new.tex > diff.tex
+
+Compares two latex files and writes tex code to stdout, which has the same
+format as new.tex but has all changes relative to old.tex marked up or commented.
+
+--type=markupstyle
+-t markupstyle         Add code to preamble for selected markup style
+                       Available styles: UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+                                         CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR
+                       [ Default: UNDERLINE ]
+
+--subtype=markstyle
+-s markstyle           Add code to preamble for selected style for bracketing
+                       commands (e.g. to mark changes in  margin)
+                       Available styles: SAFE MARGINAL DVIPSCOL
+                       [ Default: SAFE ]
+
+--floattype=markstyle
+-f markstyle           Add code to preamble for selected style which 
+                       replace standard marking and markup commands within floats
+                       (e.g., marginal remarks cause an error within floats
+                       so marginal marking can be disabled thus)
+                       Available styles: FLOATSAFE IDENTICAL
+                       [ Default: FLOATSAFE ]
+
+--encoding=enc
+-e enc                 Specify encoding of old.tex and new.tex. Typical encodings are
+                       ascii, utf8, latin1, latin9.  A list of available encodings can be 
+                       obtained by executing 
+                       perl -MEncode -e 'print join ("\\n",Encode->encodings( ":all" )) ;'
+                       [Default encoding is utf8 unless the first few lines of the preamble contain
+                       an invocation "\\usepackage[..]{inputenc} in which case the 
+                       encoding chosen by this command is asssumed. Note that ASCII (standard
+                       latex) is a subset of utf8]
+
+--preamble=file
+-p file                Insert file at end of preamble instead of auto-generating
+                       preamble.  The preamble must define the following commands
+                       \\DIFaddbegin,\\DIFaddend,\\DIFadd{..},
+                       \\DIFdelbegin,\\DIFdelend,\\DIFdel{..},
+                       and varieties for use within floats
+                       \\DIFaddbeginFL,\\DIFaddendFL,\\DIFaddFL{..},
+                       \\DIFdelbeginFL,\\DIFdelendFL,\\DIFdelFL{..}
+                       (If this option is set -t, -s, and -f options
+                       are ignored.)
+
+--exclude-safecmd=exclude-file
+--exclude-safecmd="cmd1,cmd2,..."
+-A exclude-file 
+--replace-safecmd=replace-file
+--append-safecmd=append-file
+--append-safecmd="cmd1,cmd2,..."
+-a append-file         Exclude from, replace or append to the list of regex
+                       matching commands which are safe to use within the 
+                       scope of a \\DIFadd or \\DIFdel command.  The file must contain
+                       one Perl-RegEx per line (Comment lines beginning with # or % are
+                       ignored). A literal comma within the comma-separated list must be
+                       escaped thus "\\,",   Note that the RegEx needs to match the whole of 
+                       the token, i.e., /^regex\$/ is implied and that the initial
+                       "\\" of the command is not included. The --exclude-safecmd
+                       and --append-safecmd options can be combined with the --replace-safecmd 
+                       option and can be used repeatedly to add cumulatively to the lists.
+
+--exclude-textcmd=exclude-file 
+--exclude-textcmd="cmd1,cmd2,..."
+-X exclude-file
+--replace-textcmd=replace-file
+--append-textcmd=append-file
+--append-textcmd="cmd1,cmd2,..."
+-x append-file         Exclude from, replace or append to the list of regex
+                       matching commands whose last argument is text.  See
+                       entry for --exclude-safecmd directly above for further details.
+
+--replace-context1cmd=replace-file
+--append-context1cmd=append-file
+--append-context1cmd="cmd1,cmd2,..."
+                       Replace or append to the list of regex matching commands
+                       whose last argument is text but which require a particular
+                       context to work, e.g. \\caption will only work within a figure
+                       or table.  These commands behave like text commands, except when 
+                       they occur in a deleted section, when they are disabled, but their
+                       argument is shown as deleted text.
+
+--replace-context2cmd=replace-file
+--append-context2cmd=append-file
+--append-context2cmd="cmd1,cmd2,..."
+                       As corresponding commands for context1.  The only difference is that
+                       context2 commands are completely disabled in deleted sections, including
+                       their arguments.
+
+
+--config var1=val1,var2=val2,...
+-c var1=val1,..        Set configuration variables.
+-c configfile           Available variables: 
+                          MINWORDSBLOCK (integer)
+                          FLOATENV (RegEx)
+                          PICTUREENV (RegEx)
+                          MATHENV (RegEx)
+                          MATHREPL (String)
+                          MATHARRENV (RegEx)
+                          MATHARRREPL (String)
+                          ARRENV (RegEx)
+                          COUNTERCMD (RegEx)
+                       This option can be repeated.
+
+
+--packages=pkg1,pkg2,..
+                       Tell latexdiff that .tex file is processed with the packages in list 
+                       loaded.  This is normally not necessary if the .tex file includes the
+                       preamble, as the preamble is automatically scanned for \\usepackage commands.
+                       Use of the --packages option disables automatic scanning, so if for any
+                       reason package specific parsing needs to be switched off, use --packages=none.
+                       The following packages trigger special behaviour:
+                       endfloat hyperref amsmath
+                       [ Default: scan the preamble for \\usepackage commands to determine
+                         loaded packages.]
+
+--show-preamble        Print generated or included preamble commands to stdout.
+
+--show-safecmd         Print list of regex matching and excluding safe commands.
+
+--show-textcmd         Print list of regex matching and excluding commands with text argument.
+
+--show-config          Show values of configuration variables
+
+--show-all             Show all of the above
+
+   NB For all --show commands, no old.tex or new.tex file needs to be given, and no 
+      differencing takes place.
+
+--allow-spaces         Allow spaces between bracketed or braced arguments to commands
+                       [Default requires arguments to directly follow each other without 
+                                intervening spaces]
+
+--flatten              Replace \\input and \\include commands within body by the content
+                       of the files in their argument.  If \\includeonly is present in the
+                       preamble, only those files are expanded into the document. However, 
+                       no recursion is done, i.e. \\input and \\include commands within 
+                       included sections are not expanded.  The included files are assumed to 
+                       be located in the same directories as the old and new master files,
+                       respectively, making it possible to organise files into old and new directories.
+
+--help
+-h                     Show this help text.
+
+--ignore-warnings      Suppress warnings about inconsistencies in length between input
+                       and parsed strings and missing characters. 
+
+--verbose
+-V                     Output various status information to stderr during processing.
+                       Default is to work silently.
+
+--version              Show version number.
+EOF
+}
+
+=head1 NAME
+
+latexdiff - determine and markup differences between two latex files
+
+=head1 SYNOPSIS
+
+B<latexdiff> [ B<OPTIONS> ] F<old.tex> F<new.tex> > F<diff.tex>
+
+=head1 DESCRIPTION
+
+Briefly, I<latexdiff> is a utility program to aid in the management of
+revisions of latex documents. It compares two valid latex files, here
+called C<old.tex> and C<new.tex>, finds significant differences
+between them (i.e., ignoring the number of white spaces and position
+of line breaks), and adds special commands to highlight the
+differences.  Where visual highlighting is not possible, e.g. for changes
+in the formatting, the differences are
+nevertheless marked up in the source.
+
+The program treats the preamble differently from the main document.
+Differences between the preambles are found using line-based
+differencing (similarly to the Unix diff command, but ignoring white
+spaces).  A comment, "S<C<%DIF E<gt>>>" is appended to each added line, i.e. a 
+line present in C<new.tex> but not in C<old.tex>.  Discarded lines 
+ are deactivated by prepending "S<C<%DIF E<lt>>>". Changed blocks are preceded  by
+comment lines giving information about line numbers in the original files.  Where there are insignificant
+differences, the resulting file C<diff.tex> will be similar to
+C<new.tex>.  At the end of the preamble, the definitions for I<latexdiff> markup commands are inserted.
+In differencing the main body of the text, I<latexdiff> attempts to
+satisfy the following guidelines (in order of priority):
+
+=over 3
+
+=item 1
+
+If both C<old.tex> and C<new.tex> are valid LaTeX, then the resulting
+C<diff.tex> should also be valid LateX. (NB If a few plain TeX commands
+are used within C<old.tex> or C<new.tex> then C<diff.tex> is not
+guaranteed to work but usually will).
+
+=item 2
+
+Significant differences are determined on the level of
+individual words. All significant differences, including differences
+between comments should be clearly marked in the resulting source code
+C<diff.tex>.
+
+=item 3
+
+If a changed passage contains text or text-producing commands, then
+running C<diff.tex> through LateX should produce output where added
+and discarded passages are highlighted.
+
+=item 4
+
+Where there are insignificant differences, e.g. in the positioning of
+line breaks, C<diff.tex> should follow the formatting of C<new.tex>
+
+=back
+
+For differencing the same algorithm as I<diff> is used but words
+instead of lines are compared.  An attempt is made to recognize
+blocks which are completely changed such that they can be marked up as a unit.
+Comments are differenced line by line
+but the number of spaces within comments is ignored. Commands including
+all their arguments are generally compared as one unit, i.e., no mark-up
+is inserted into the arguments of commands.  However, for a selected
+number of commands (for example, C<\caption> and all sectioning
+commands) the last argument is known to be text. This text is
+split into words and differenced just as ordinary text (use options to
+show and change the list of text commands, see below). As the
+algorithm has no detailed knowledge of LaTeX, it assumes all pairs of
+curly braces immediately following a command (i.e. a sequence of
+letters beginning with a backslash) are arguments for that command.
+As a restriction to condition 1 above it is thus necessary to surround
+all arguments with curly braces, and to not insert
+extraneous spaces.  For example, write 
+
+  \section{\textem{This is an emphasized section title}}
+
+and not
+
+  \section {\textem{This is an emphasized section title}}
+
+or
+
+  \section\textem{This is an emphasized section title}
+
+even though all varieties are the same to LaTeX (but see
+B<--allow-spaces> option which allows the second variety).
+
+For environments whose content does not conform to standard LaTeX or
+where graphical markup does not make sense all markup commands can be
+removed by setting the PICTUREENV configuration variable, set by
+default to C<picture> and C<DIFnomarkup> environments; see B<--config>
+option).  The latter environment (C<DIFnomarkup>) can be used to
+protect parts of the latex file where the markup results in illegal
+markup. You have to surround the offending passage in both the old and
+new file by C<\begin{DIFnomarkup}> and C<\end{DIFnomarkup}>. You must
+define the environment in the preambles of both old and new
+documents. I prefer to define it as a null-environment,
+
+C<\newenvironment{DIFnomarkup}{}{}>
+
+but the choice is yours.  Any markup within the environment will be
+removed, and generally everything within the environment will just be
+taken from the new file.
+
+It is also possible to difference files which do not have a preamble. 
+ In this case, the file is processed in the main document
+mode, but the definitions of the markup commands are not inserted.
+
+All markup commands inserted by I<latexdiff> begin with "C<\DIF>".  Added
+blocks containing words, commands or comments which are in C<new.tex>
+but not in C<old.tex> are marked by C<\DIFaddbegin> and C<\DIFaddend>.
+Discarded blocks are marked by C<\DIFdelbegin> and C<\DIFdelend>.
+Within added blocks all text is highlighted with C<\DIFadd> like this:
+C<\DIFadd{Added text block}>
+Selected `safe' commands can be contained in these text blocks as well
+(use options to show and change the list of safe commands, see below).
+All other commands as well as braces "{" and "}" are never put within
+the scope of C<\DIFadd>.  Added comments are marked by prepending
+"S<C<%DIF E<gt> >>".
+
+Within deleted blocks text is highlighted with C<\DIFdel>.  Deleted
+comments are marked by prepending "S<C<%DIF E<lt> >>".  Non-safe command
+and curly braces within deleted blocks are commented out with 
+"S<C<%DIFDELCMD E<lt> >>".
+
+
+
+=head1 OPTIONS
+
+=head2 Preamble
+
+The following options determine the visual markup style by adding the appropriate
+command definitions to the preamble. See the end of this section for a description of 
+available styles.
+
+=over 4
+
+=item B<--type=markupstyle> or
+B<-t markupstyle>
+
+Add code to preamble for selected markup style. This option defines
+C<\DIFadd> and C<\DIFdel> commands.
+Available styles: 
+
+C<UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR>
+
+[ Default: C<UNDERLINE> ]
+
+=item B<--subtype=markstyle> or
+B<-s markstyle> 
+
+Add code to preamble for selected style for bracketing
+commands (e.g. to mark changes in  margin). This option defines
+C<\DIFaddbegin>, C<\DIFaddend>, C<\DIFdelbegin> and C<\DIFdelend> commands.
+Available styles: C<SAFE MARGINAL DVIPSCOL>
+
+[ Default: C<SAFE> ]
+
+=item B<--floattype=markstyle> or
+B<-f markstyle>
+
+Add code to preamble for selected style which 
+replace standard marking and markup commands within floats
+(e.g., marginal remarks cause an error within floats
+so marginal marking can be disabled thus). This option defines all 
+C<\DIF...FL> commands.
+Available styles: C<FLOATSAFE TRADITIONALSAFE IDENTICAL>
+
+[ Default: C<FLOATSAFE> ]
+
+=item B<--encoding=enc> or 
+B<-e enc>
+
+Specify encoding of old.tex and new.tex. Typical encodings are
+C<ascii>, C<utf8>, C<latin1>, C<latin9>.  A list of available encodings can be 
+obtained by executing 
+
+C<perl -MEncode -e 'print join ("\n",Encode->encodings( ":all" )) ;' >
+
+[Default encoding is utf8 unless the first few lines of the preamble contain
+an invocation C<\usepackage[..]{inputenc}> in which case the 
+encoding chosen by this command is asssumed. Note that ASCII (standard
+latex) is a subset of utf8]
+
+=item B<--preamble=file> or
+B<-p file>
+
+Insert file at end of preamble instead of generating
+preamble.  The preamble must define the following commands
+C<\DIFaddbegin, \DIFaddend, \DIFadd{..},
+\DIFdelbegin,\DIFdelend,\DIFdel{..},>
+and varieties for use within floats
+C<\DIFaddbeginFL, \DIFaddendFL, \DIFaddFL{..},
+\DIFdelbeginFL, \DIFdelendFL, \DIFdelFL{..}>
+(If this option is set B<-t>, B<-s>, and B<-f> options
+are ignored.)
+
+=item B<--packages=pkg1,pkg2,..> 
+
+Tell latexdiff that .tex file is processed with the packages in list
+loaded.  This is normally not necessary if the .tex file includes the
+preamble, as the preamble is automatically scanned for C<\usepackage> commands.
+Use of the B<--packages> option disables automatic scanning, so if for any
+reason package specific parsing needs to be switched off, use B<--packages=none>.
+The following packages trigger special behaviour:
+
+=over 8
+
+=item C<amsmath> 
+
+Configuration variable amsmath is set to C<align*> (Default: C<eqnarray*>)
+
+=item C<endfloat> 
+
+Ensure that C<\begin{figure}> and C<\end{figure}> always appear by themselves on a line.
+
+=item C<hyperref>
+
+Change name of C<\DIFadd> and C<\DIFdel> commands to C<\DIFaddtex> and C<\DIFdeltex> and 
+define new C<\DIFadd> and C<\DIFdel> commands, which provide a wrapper for these commands,
+using them for the text but not for the link defining command (where any markup would cause
+errors).
+
+=back
+
+[ Default: scan the preamble for C<\\usepackage> commands to determine
+  loaded packages.]
+
+
+
+=item B<--show-preamble>
+
+Print generated or included preamble commands to stdout.
+
+=back
+
+=head2 Configuration
+
+=over 4
+
+=item B<--exclude-safecmd=exclude-file> or
+B<-A exclude-file> or  B<--exclude-safecmd="cmd1,cmd2,...">
+
+=item B<--replace-safecmd=replace-file>
+
+=item B<--append-safecmd=append-file> or 
+B<-a append-file> or B<--append-safecmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions (RegEx)
+matching commands which are safe to use within the 
+scope of a C<\DIFadd> or C<\DIFdel> command.  The file must contain
+one Perl-RegEx per line (Comment lines beginning with # or % are
+ignored).  Note that the RegEx needs to match the whole of 
+the token, i.e., /^regex$/ is implied and that the initial
+"\" of the command is not included. 
+The B<--exclude-safecmd> and B<--append-safecmd> options can be combined with the -B<--replace-safecmd> 
+option and can be used repeatedly to add cumulatively to the lists.
+ B<--exclude-safecmd>
+and B<--append-safecmd> can also take a comma separated list as input. If a
+comma for one of the regex is required, escape it thus "\,". In most cases it
+will be necessary to protect the comma-separated list from the shell by putting
+it in quotation marks.
+
+=item B<--exclude-textcmd=exclude-file> or
+B<-X exclude-file> or B<--exclude-textcmd="cmd1,cmd2,...">
+
+=item B<--replace-textcmd=replace-file>
+
+=item B<--append-textcmd=append-file> or 
+B<-x append-file> or B<--append-textcmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions
+matching commands whose last argument is text.  See
+entry for B<--exclude-safecmd> directly above for further details.
+
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context1cmd=append-file> or
+=item B<--append-context1cmd="cmd1,cmd2,...">
+
+Replace or append to the list of regex matching commands
+whose last argument is text but which require a particular
+context to work, e.g. \caption will only work within a figure
+or table.  These commands behave like text commands, except when 
+they occur in a deleted section, when they are disabled, but their
+argument is shown as deleted text.
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context2cmd=append-file> or
+=item B<--append-context2cmd="cmd1,cmd2,...">
+As corresponding commands for context1.  The only difference is that
+context2 commands are completely disabled in deleted sections, including
+their arguments.
+
+
+
+=item B<--config var1=val1,var2=val2,...> or B<-c var1=val1,..>
+
+=item B<-c configfile>
+
+Set configuration variables.  The option can be repeated to set different
+variables (as an alternative to the comma-separated list).
+Available variables (see below for further explanations): 
+
+C<MINWORDSBLOCK> (integer)
+
+C<FLOATENV> (RegEx)
+
+C<PICTUREENV> (RegEx)
+
+C<MATHENV> (RegEx)
+
+C<MATHREPL> (String)
+
+C<MATHARRENV> (RegEx)
+
+C<MATHARRREPL> (String)
+
+C<ARRENV> (RegEx)
+
+C<COUNTERCMD> (RegEx)
+
+=item B<--show-safecmd>
+
+Print list of RegEx matching and excluding safe commands.
+
+=item B<--show-textcmd>
+
+Print list of RegEx matching and excluding commands with text argument.
+
+=item B<--show-config>
+
+Show values of configuration variables.
+
+=item B<--show-all>
+
+Combine all --show commands.
+
+NB For all --show commands, no C<old.tex> or C<new.tex> file needs to be specified, and no 
+differencing takes place.
+
+
+=back
+
+=head2 Miscellaneous
+
+=over 4
+
+=item B<--verbose> or B<-V>
+
+Output various status information to stderr during processing.
+Default is to work silently.
+
+=item B<--ignore-warnings>
+
+Suppress warnings about inconsistencies in length between input and
+parsed strings and missing characters.  These warning messages are
+often related to non-standard latex or latex constructions with a
+syntax unknown to C<latexdiff> but the resulting difference argument
+is often fully functional anyway, particularly if the non-standard
+latex only occurs in parts of the text which have not changed.
+
+=item B<--allow-spaces>
+
+Allow spaces between bracketed or braced arguments to commands.  Note
+that this option might have undesirable side effects (unrelated scope
+might get lumpeded with preceding commands) so should only be used if the
+default produces erroneous results.  (Default requires arguments to
+directly follow each other without intervening spaces).
+
+=item B<--flatten>
+
+Replace C<\input> and C<\include> commands within body by the content
+of the files in their argument.  If C<\includeonly> is present in the
+preamble, only those files are expanded into the document. However, 
+no recursion is done, i.e. C<\input> and C<\include> commands within 
+included sections are not expanded.  The included files are assumed to 
+ be located in the same directories as the old and new master files,
+respectively, making it possible to organise files into old and new directories. 
+
+Use of this option is not recommended
+primarily the processing time for the large documents is prohibitive, and
+the resulting difference document no longer reflects the structure of the 
+input documents. 
+
+=item B<--help> or
+B<-h>
+
+Show help text
+
+=item B<--version>
+
+Show version number
+
+=back
+
+=head2 Predefined styles 
+
+=head2 Major types
+
+The major type determine the markup of plain text and some selected latex commands outside floats by defining the markup commands C<\DIFadd{...}> and C<\DIFdel{...}> .
+
+=over 10
+
+=item C<UNDERLINE>
+
+Added text is wavy-underlined and blue, discarded text is struck out and red
+(Requires color and ulem packages).  Overstriking does not work in displayed math equations such that deleted parts of equation are underlined, not struck out (this is a shortcoming inherent to the ulem package).
+
+=item C<CTRADITIONAL>
+
+Added text is blue and set in sans-serif, and a red footnote is created for each discarded 
+piece of text. (Requires color package)
+
+=item C<TRADITIONAL>
+
+Like C<CTRADITIONAL> but without the use of color.
+
+=item C<CFONT>
+
+Added text is blue and set in sans-serif, and discarded text is red and very small size.
+
+=item C<FONTSTRIKE>
+
+Added tex is set in sans-serif, discarded text small and struck out
+
+=item C<CCHANGEBAR>
+
+Added text is blue, and discarded text is red.  Additionally, the changed text is marked with a bar in the margin (Requires color and changebar packages).
+
+=item C<CFONTCHBAR>
+
+Like C<CFONT> but with additional changebars (Requires color and changebar packages).
+
+=item C<CULINECHBAR>
+
+Like C<UNDERLINE> but with additional changebars (Requires color, ulem and changebar packages).
+
+=item C<CHANGEBAR>
+
+No mark up of text, but mark margins with changebars (Requires changebar package).
+
+=item C<INVISIBLE>
+
+No visible markup (but generic markup commands will still be inserted.
+
+=back
+
+=head2 Subtypes
+
+The subtype defines the commands that are inserted at the begin and end of added or discarded blocks, irrespectively of whether these blocks contain text or commands (Defined commands: C<\DIFaddbegin, \DIFaddend, \DIFdelbegin, \DIFdelend>) 
+
+=over 10
+
+=item C<SAFE>
+
+No additional markup (Recommended choice)
+
+=item C<MARGIN>
+
+Mark beginning and end of changed blocks with symbols in the margin nearby (using
+the standard C<\marginpar> command - note that this sometimes moves somewhat
+from the intended position.
+
+=item C<DVIPSCOL>
+
+An alternative way of marking added passages in blue, and deleted ones in red. Note
+that C<DVIPSCOL> only works with the dvips converter, e.g. not pdflatex.
+(it is recommeneded to use instead the main types to effect colored markup,
+although in some cases coloring with dvipscol can be more complete).
+
+=back
+
+=head2 Float Types
+
+Some of the markup used in the main text might cause problems when used within 
+floats (e.g. figures or tables).  For this reason alternative versions of all
+markup commands are used within floats. The float type defines these alternative commands.
+
+=over 10
+
+=item C<FLOATSAFE>
+
+Use identical markup for text as in the main body, but set all commands marking the begin and end of changed blocks to null-commands.  You have to choose this float type if your subtype is C<MARGIN> as C<\marginpar> does not work properly within floats.
+
+=item C<TRADITIONALSAFE>
+
+Mark additions the same way as in the main text.  Deleted environments are marked by angular brackets \[ and \] and the deleted text is set in scriptscript size. This float type should always be used with the C<TRADITIONAL> and  C<CTRADITIONAL> markup types as the \footnote command does not work properly in floating environments.
+
+=item C<IDENTICAL>
+
+Make no difference between the main text and floats.
+
+=back
+
+
+=head2 Configuration Variables
+
+=over 10
+
+=item C<MINWORDSBLOCK>
+
+Minimum number of tokens required to form an independent block. This value is
+used in the algorithm to detect changes of complete blocks by merging identical text parts of less than C<MINWORDSBLOCK> to the preceding added and discarded parts.
+
+[ Default: 3 ]
+
+=item C<FLOATENV>
+
+Environments whose name matches the regular expression in C<FLOATENV> are 
+considered floats.  Within these environments, the I<latexdiff> markup commands
+are replaced by their FL variaties.
+
+[ Default: S<C<(?:figure|table|plate)[\w\d*@]*> >]
+
+=item C<PICTUREENV>
+
+Within environments whose name matches the regular expression in C<PICTUREENV>
+all latexdiff markup is removed (in pathologic cases this might lead to
+ inconsistent markup but this situation should be rare).
+
+[ Default: S<C<(?:picture|DIFnomarkup)[\w\d*@]*> >]
+
+=item C<MATHENV>,C<MATHREPL>
+
+If both \begin and \end for a math environment (environment name matching C<MATHENV>
+or \[ and \])
+are within the same deleted block, they are replaced by a \begin and \end commands for C<MATHREPL>
+rather than being commented out.
+
+[ Default: C<MATHENV>=S<C<(?:displaymath|equation)> >, C<MATHREPL>=S<C<displaymath> >]
+
+=item C<MATHARRENV>,C<MATHARRREPL>
+
+as C<MATHENV>,C<MATHREPL> but for equation arrays
+
+[ Default: C<MATHARRENV>=S<C<eqnarray\*?> >, C<MATHREPL>=S<C<eqnarray> >]
+
+=item C<ARRENV>
+
+If a match to C<ARRENV> is found within an inline math environment within a deleted or added block, then the inlined math 
+is surrounded by C<\mbox{>...C<}>.  This is necessary as underlining does not work within inlined array environments.
+
+[ Default: C<ARRENV>=S<C<(?:array|[pbvBV]matrix)> >
+
+=item C<COUNTERCMD>
+
+If a command in a deleted block which is also in the textcmd list matches C<COUNTERCMD> then an
+additional command C<\addtocounter{>F<cntcmd>C<}{-1}>, where F<cntcmd> is the matching command, is appended in the diff file such that the numbering in the diff file remains synchronized with the
+numbering in the new file.
+
+[ Default: C<COUNTERCMD>=C<(?:footnote|part|section|subsection> ...
+
+C<|subsubsection|paragraph|subparagraph)>  ]
+
+=back
+
+=head1 BUGS
+
+UTF-8 support requires a relatively new version of perl (5.8.0 is sufficient 
+but 5.6.2 up would work OK, too).
+
+Option allow-spaces not implemented entirely consistently. It breaks
+the rules that number and type of white space does not matter, as
+different numbers of inter-argument spaces are treated as significant.
+
+Please send bug reports
+to I<tilmann@esc.cam.ac.uk>.  Include the serial number of I<latexdiff>
+(from comments at the top of the source or use B<--version>).  If you come across latex
+files that are error-free and conform to the specifications set out
+above, and whose differencing still does not result in error-free
+latex, please send me those files, ideally edited to only contain the
+offending passage as long as that still reproduces the problem. 
+
+=head1 SEE ALSO
+
+L<latexrevise>
+
+=head1 PORTABILITY
+
+I<latexdiff> does not make use of external commands and thus should run
+on any platform  supporting Perl 5.6 or higher.  If files with encodings 
+other than ASCII or UTF-8 are processed, Perl 5.8 or higher is required.
+
+The standard version of I<latexdiff> requires installation of the Perl package
+C<Algorithm::Diff> (available from I<www.cpan.org> - 
+I<http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15>) but a stand-alone
+version, I<latexdiff-so>, which has this package inlined, is available, too.
+I<latexdiff-fast> requires the I<diff> command to be present.
+
+=head1 AUTHOR
+
+Copyright (C) 2004-2007 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+
+Contributors of fixes and additions: V. Kuhlmann, J. Paisley, N. Becker, T. Doerges, K. Huebner
+Thanks to everyone who send in bug reports.
+
+=cut
+
+__END__
+%%BEGIN SAFE COMMANDS
+% Regex matching commands which can safely be in the
+% argument of a \DIFadd or \DIFdel command (leave out the \)
+arabic
+dashbox
+emph
+fbox
+framebox
+hspace
+math.*
+makebox
+mbox
+pageref
+ref
+symbol
+raisebox
+rule
+text.*
+shortstack
+usebox
+dag
+ddag
+copyright
+pounds
+S
+P
+oe
+OE
+ae
+AE
+aa
+AA
+o
+O
+l
+L
+frac
+ss
+sqrt
+ldots
+cdots
+vdots
+ddots
+alpha
+beta
+gamma
+delta
+epsilon
+varepsilon
+zeta
+eta
+theta
+vartheta
+iota
+kappa
+lambda
+mu
+nu
+xi
+pi
+varpi
+rho
+varrho
+sigma
+varsigma
+tau
+upsilon
+phi
+varphi
+chi
+psi
+omega
+Gamma
+Delta
+Theta
+Lambda
+Xi
+Pi
+Sigma
+Upsilon
+Phi
+Psi
+Omega
+ps
+mp
+times
+div
+ast
+star
+circ
+bullet
+cdot
+cap
+cup
+uplus
+sqcap
+vee
+wedge
+setminus
+wr
+diamond
+(?:big)?triangle.*
+lhd
+rhd
+unlhd
+unrhd
+oplus
+ominus
+otimes
+oslash
+odot
+bigcirc
+d?dagger
+amalg
+leq
+prec
+preceq
+ll
+(?:sq)?su[bp]set(?:eq)?
+in
+vdash
+geq
+succ(?:eq)?
+gg
+ni
+dashv
+equiv
+sim(?:eq)?
+asymp
+approx
+cong
+neq
+doteq
+propto
+models
+perp
+mid
+parallel
+bowtie
+Join
+smile
+frown
+.*arrow
+(?:long)?mapsto
+.*harpoon.*
+leadsto
+aleph
+hbar
+imath
+jmath
+ell
+wp
+Re
+Im
+mho
+prime
+emptyset
+nabla
+surd
+top
+bot
+angle
+forall
+exists
+neg
+flat
+natural
+sharp
+backslash
+partial
+infty
+Box
+Diamond
+triangle
+clubsuit
+diamondsuit
+heartsuit
+spadesuit
+sum
+prod
+coprod
+int
+oint
+big(?:sq)?c[au]p
+bigvee
+bigwedge
+bigodot
+bigotimes
+bigoplus
+biguplus
+(?:arc)?(?:cos|sin|tan|cot)h?
+csc
+arg
+deg
+det
+dim
+exp
+gcd
+hom
+inf
+ker
+lg
+lim
+liminf
+limsup
+ln
+log
+max
+min
+Pr
+sec
+sup
+(SUPER|SUB)SCRIPTNB
+(SUPER|SUB)SCRIPT
+%%END SAFE COMMANDS
+
+%%BEGIN TEXT COMMANDS
+% Regex matching commands with a text argument (leave out the \)
+addcontents.*
+cc
+closing
+chapter
+dashbox
+emph
+encl
+fbox
+framebox
+footnote
+footnotetext
+framebox
+part
+(sub){0,2}section\*?
+(sub)?paragraph\*?
+makebox
+mbox
+opening
+parbox
+raisebox
+savebox
+sbox
+shortstack
+signature
+text.*
+value
+underline
+sqrt
+(SUPER|SUB)SCRIPT
+%%END TEXT COMMANDS 
+
+%%BEGIN CONTEXT1 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+caption
+%%END CONTEXT1 COMMANDS 
+
+%%BEGIN CONTEXT2 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+title
+author
+%%END CONTEXT2 COMMANDS 
+
+
+%% TYPES (Commands for highlighting changed blocks)
+
+%DIF UNDERLINE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue}\uwave{#1}}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}\sout{#1}}}                     
+%DIF END UNDERLINE PREAMBLE
+
+%DIF CTRADITIONAL PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} [..\footnote{removed: #1} ]}}
+%DIF END CTRADITIONAL PREAMBLE
+
+%DIF TRADITIONAL PREAMBLE
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{[..\footnote{removed: #1} ]}}
+%DIF END TRADITIONAL PREAMBLE
+
+%DIF CFONT PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} \scriptsize #1}}
+%DIF END CFONT PREAMBLE
+
+%DIF FONTSTRIKE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{\footnotesize \sout{#1}}}
+%DIF END FONTSTRIKE PREAMBLE
+
+%DIF CCHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}#1}\protect\cbdelete}
+%DIF END CCHANGEBAR PREAMBLE
+
+%DIF CFONTCHBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\sf #1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\scriptsize #1}\protect\cbdelete}
+%DIF END CFONTCHBAR PREAMBLE
+
+%DIF CULINECHBAR PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\uwave{#1}}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\sout{#1}}\protect\cbdelete}
+%DIF END CULINECHBAR PREAMBLE
+
+%DIF CHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\providecommand{\DIFadd}[1]{\protect\cbstart{#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete}
+%DIF END CHANGEBAR PREAMBLE
+
+%DIF INVISIBLE PREAMBLE
+\providecommand{\DIFadd}[1]{#1}
+\providecommand{\DIFdel}[1]{}
+%DIF END INVISIBLE PREAMBLE
+
+
+%% SUBTYPES (Markers for beginning and end of changed blocks)
+
+%DIF SAFE PREAMBLE
+\providecommand{\DIFaddbegin}{}
+\providecommand{\DIFaddend}{}
+\providecommand{\DIFdelbegin}{}
+\providecommand{\DIFdelend}{}
+%DIF END SAFE PREAMBLE
+
+%DIF MARGIN PREAMBLE
+\providecommand{\DIFaddbegin}{\protect\marginpar{a[}}
+\providecommand{\DIFaddend}{\protect\marginpar{]}}
+\providecommand{\DIFdelbegin}{\protect\marginpar{d[}}
+\providecommand{\DIFdelend}{\protect\marginpar{]}}
+%DIF END BRACKET PREAMBLE
+
+%DIF DVIPSCOL PREAMBLE
+%Note: only works with dvips converter
+\RequirePackage{color}
+\RequirePackage{dvipscol}
+\providecommand{\DIFaddbegin}{\protect\nogroupcolor{blue}}
+\providecommand{\DIFaddend}{\protect\nogroupcolor{black}}
+\providecommand{\DIFdelbegin}{\protect\nogroupcolor{red}}
+\providecommand{\DIFdelend}{\protect\nogroupcolor{black}}
+%DIF END DVIPSCOL PREAMBLE
+
+
+%% FLOAT TYPES 
+
+%DIF FLOATSAFE PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%DIF IDENTICAL PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{\DIFaddbegin}
+\providecommand{\DIFaddendFL}{\DIFaddend}
+\providecommand{\DIFdelbeginFL}{\DIFdelbegin}
+\providecommand{\DIFdelendFL}{\DIFdelend}
+%DIF END IDENTICAL PREAMBLE
+
+%DIF TRADITIONALSAFE PREAMBLE
+% procidecommand color to make this work for TRADITIONAL and CTRADITIONAL
+\providecommand{\color}[1]{}
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}[..{\scriptsize {removed: #1}} ]}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%% SPECIAL PACKAGE PREAMBLE COMMANDS
+
+% Standard \DIFadd and \DIFdel are redefined as \DIFaddtex and \DIFdeltex
+% when hyperref package is included.
+%DIF HYPERREF PREAMBLE
+\providecommand{\DIFadd}[1]{\texorpdfstring{\DIFaddtex{#1}}{#1}}
+\providecommand{\DIFdel}[1]{\texorpdfstring{\DIFdeltex{#1}}{}}
+%DIF END HYPERREF PACKAGE
diff --git a/Master/texmf-dist/doc/latex/latexdiff/latexdiff-fast b/Master/texmf-dist/doc/latex/latexdiff/latexdiff-fast
new file mode 100755
index 00000000000..ee6c7419ac9
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/latexdiff-fast
@@ -0,0 +1,3344 @@
+#!/usr/bin/perl -w
+# latexdiff - differences two latex files on the word level
+#             and produces a latex file with the differences marked up.
+#
+#   Copyright (C) 2004-2007  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# Version 0.5  A number of minor improvements based on feedback
+#              Deleted blocks are now shown before added blocks
+#              Package specific processing
+#
+# Version 0.43 unreleased typo in list of styles at the end
+#              Add protect to all \cbstart, \cbend commands
+#              More robust substitution of deleted math commands
+#
+# Version 0.42 November 06  Bug fixes only
+#
+# Version 0.4   March 06 option for fast differencing using UNIX diff command, several minor bug fixes (\par bug, improved highlighting of textcmds)
+#
+# Version 0.3   August 05 improved parsing of displayed math, --allow-spaces 
+#               option, several minor bug fixes
+#
+# Version 0.25  October 04 Fix bug with deleted equations, add math mode commands to safecmd, add | to allowed interpunctuation signs
+# Version 0.2   September 04 extension to utf-8 and variable encodings
+# Version 0.1   August 04    First public release
+
+# Inserted block for differenceing 
+# use Algorithm::Diff qw(traverse_sequences);
+# in standard version
+# The following BEGIN block contains a verbatim copy of
+# Ned Konz' Algorithm::Diff package version 1.15 except
+# that subroutine _longestCommonSubsequence has been replace by 
+# a routine which internally uses the UNIX diff command for
+# the differencing rather than the Perl routines if the 
+# length of the sequences exceeds some threshold.
+# Also, all POD documentation has been stripped out.
+#
+# (the distribution on which this modification is based is available
+#  from http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15
+#  the most recent version can be found via  http://search.cpan.org/search?module=Algorithm::Diff )
+# Please note that the LICENCSE for Algorithm::Diff :
+#   "Copyright (c) 2000-2002 Ned Konz.  All rights reserved.
+#    This program is free software;
+#    you can redistribute it and/or modify it under the same terms
+#    as Perl itself."
+# The fast-differencing version of latexdiff is provided as a convenience
+# for latex users under Unix-like systems which have a 'diff' command.
+# If you believe
+# the inlining of Algorithm::Diff violates its license please contact
+# me and I will modify the latexdiff distribution accordingly.
+# Frederik Tilmann (tilmann@esc.cam.ac.uk)
+# Jonathan Paisley is acknowledged for the idea of using the system diff
+# command to achieve shorter running times
+BEGIN { 
+package Algorithm::Diff;
+use strict;
+use vars qw($VERSION @EXPORT_OK @ISA @EXPORT);
+use integer;    # see below in _replaceNextLargerWith() for mod to make
+                # if you don't use this
+require Exporter;
+@ISA       = qw(Exporter);
+@EXPORT    = qw();
+@EXPORT_OK = qw(LCS diff traverse_sequences traverse_balanced sdiff);
+$VERSION = sprintf('%d.%02d fast', (q$Revision: 1.15 $ =~ /\d+/g));
+
+# Global parameters
+
+use File::Temp qw/tempfile/;
+# if larger number of elements in longestCommonSubsequence smaller than
+# this number, then use internal algorithm, otherwise use UNIX diff
+use constant THRESHOLD => 100 ; 
+# Detect whether diff --minimal option is available
+# if yes we use it
+use constant MINIMAL => ( system('diff','--minimal','/dev/null','/dev/null') >> 8 ==0 ? "--minimal" : "" ) ;
+
+
+
+# McIlroy-Hunt diff algorithm
+# Adapted from the Smalltalk code of Mario I. Wolczko, <mario@wolczko.com>
+# by Ned Konz, perl@bike-nomad.com
+
+
+# Create a hash that maps each element of $aCollection to the set of positions
+# it occupies in $aCollection, restricted to the elements within the range of
+# indexes specified by $start and $end.
+# The fourth parameter is a subroutine reference that will be called to
+# generate a string to use as a key.
+# Additional parameters, if any, will be passed to this subroutine.
+#
+# my $hashRef = _withPositionsOfInInterval( \@array, $start, $end, $keyGen );
+
+sub _withPositionsOfInInterval
+{
+	my $aCollection = shift;    # array ref
+	my $start       = shift;
+	my $end         = shift;
+	my $keyGen      = shift;
+	my %d;
+	my $index;
+	for ( $index = $start ; $index <= $end ; $index++ )
+	{
+		my $element = $aCollection->[$index];
+		my $key = &$keyGen( $element, @_ );
+		if ( exists( $d{$key} ) )
+		{
+			unshift ( @{ $d{$key} }, $index );
+		}
+		else
+		{
+			$d{$key} = [$index];
+		}
+	}
+	return wantarray ? %d : \%d;
+}
+
+# Find the place at which aValue would normally be inserted into the array. If
+# that place is already occupied by aValue, do nothing, and return undef. If
+# the place does not exist (i.e., it is off the end of the array), add it to
+# the end, otherwise replace the element at that point with aValue.
+# It is assumed that the array's values are numeric.
+# This is where the bulk (75%) of the time is spent in this module, so try to
+# make it fast!
+
+sub _replaceNextLargerWith
+{
+	my ( $array, $aValue, $high ) = @_;
+	$high ||= $#$array;
+
+	# off the end?
+	if ( $high == -1 || $aValue > $array->[-1] )
+	{
+		push ( @$array, $aValue );
+		return $high + 1;
+	}
+
+	# binary search for insertion point...
+	my $low = 0;
+	my $index;
+	my $found;
+	while ( $low <= $high )
+	{
+		$index = ( $high + $low ) / 2;
+
+		#		$index = int(( $high + $low ) / 2);		# without 'use integer'
+		$found = $array->[$index];
+
+		if ( $aValue == $found )
+		{
+			return undef;
+		}
+		elsif ( $aValue > $found )
+		{
+			$low = $index + 1;
+		}
+		else
+		{
+			$high = $index - 1;
+		}
+	}
+
+	# now insertion point is in $low.
+	$array->[$low] = $aValue;    # overwrite next larger
+	return $low;
+}
+
+# This method computes the longest common subsequence in $a and $b.
+
+# Result is array or ref, whose contents is such that
+# 	$a->[ $i ] == $b->[ $result[ $i ] ]
+# foreach $i in ( 0 .. $#result ) if $result[ $i ] is defined.
+
+# An additional argument may be passed; this is a hash or key generating
+# function that should return a string that uniquely identifies the given
+# element.  It should be the case that if the key is the same, the elements
+# will compare the same. If this parameter is undef or missing, the key
+# will be the element as a string.
+
+# By default, comparisons will use "eq" and elements will be turned into keys
+# using the default stringizing operator '""'.
+
+# Additional parameters, if any, will be passed to the key generation routine.
+
+sub _longestCommonSubsequence
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $keyGen = shift;    # code ref
+	my $compare;           # code ref
+
+	# set up code refs
+	# Note that these are optimized.
+	if ( !defined($keyGen) )    # optimize for strings
+	{
+		$keyGen = sub { $_[0] };
+		$compare = sub { my ( $a, $b ) = @_; $a eq $b };
+	}
+	else
+	{
+		$compare = sub {
+			my $a = shift;
+			my $b = shift;
+			&$keyGen( $a, @_ ) eq &$keyGen( $b, @_ );
+		};
+	}
+
+	my ( $aStart, $aFinish, $bStart, $bFinish, $matchVector ) =
+	  ( 0, $#$a, 0, $#$b, [] );
+
+	# Check whether to use internal routine (small number of elements)
+	# or use it as a wrapper for UNIX diff
+	if ( ( $#$a > $#$b ?  $#$a : $#$b) < THRESHOLD ) {
+	  ###	  print STDERR "DEBUG: regular longestCommonSubsequence\n";
+	  # First we prune off any common elements at the beginning
+	  while ( $aStart <= $aFinish
+		  and $bStart <= $bFinish
+		  and &$compare( $a->[$aStart], $b->[$bStart], @_ ) )
+	    {
+	      $matchVector->[ $aStart++ ] = $bStart++;
+	    }
+
+	  # now the end
+	  while ( $aStart <= $aFinish
+		and $bStart <= $bFinish
+		and &$compare( $a->[$aFinish], $b->[$bFinish], @_ ) )
+	    {
+	      $matchVector->[ $aFinish-- ] = $bFinish--;
+	    }
+
+	  # Now compute the equivalence classes of positions of elements
+	  my $bMatches =
+	    _withPositionsOfInInterval( $b, $bStart, $bFinish, $keyGen, @_ );
+	  my $thresh = [];
+	  my $links  = [];
+	  
+	  my ( $i, $ai, $j, $k );
+	  for ( $i = $aStart ; $i <= $aFinish ; $i++ )
+	    {
+	      $ai = &$keyGen( $a->[$i], @_ );
+	      if ( exists( $bMatches->{$ai} ) )
+		{
+		  $k = 0;
+		  for $j ( @{ $bMatches->{$ai} } )
+		    {
+		      
+		      # optimization: most of the time this will be true
+		      if ( $k and $thresh->[$k] > $j and $thresh->[ $k - 1 ] < $j )
+			{
+			  $thresh->[$k] = $j;
+			}
+		      else
+			{
+			  $k = _replaceNextLargerWith( $thresh, $j, $k );
+			}
+		      
+		      # oddly, it's faster to always test this (CPU cache?).
+		      if ( defined($k) )
+			{
+			  $links->[$k] =
+			    [ ( $k ? $links->[ $k - 1 ] : undef ), $i, $j ];
+			}
+		    }
+		}
+	    }
+
+	  if (@$thresh)
+	    {
+	      for ( my $link = $links->[$#$thresh] ; $link ; $link = $link->[0] )
+		{
+		  $matchVector->[ $link->[1] ] = $link->[2];
+		}
+	    }
+	}
+	else {
+	  my ($fha,$fhb,$fna,$fnb,$ele,$key);
+	  my ($alines,$blines,$alb,$alf,$blb,$blf);
+	  my ($minimal)=MINIMAL;
+	  # large number of elements, use system diff
+	  ###	  print STDERR "DEBUG: fast (diff) longestCommonSubsequence\n";
+
+	  ($fha,$fna)=tempfile("DiffA-XXXX") or die "_longestCommonSubsequence: Cannot open tempfile for sequence A";
+	  ($fhb,$fnb)=tempfile("DiffB-XXXX") or die "_longestCommonSubsequence: Cannot open tempfile for sequence B";
+	  # prepare sequence A
+	  foreach $ele ( @$a ) {
+	    $key=&$keyGen( $ele, @_ );
+	    $key =~ s/\\/\\\\/g ;
+	    $key =~ s/\n/\\n/sg ;
+	    print $fha "$key\n" ;
+	  }
+	  close($fha);
+	  # prepare sequence B
+	  foreach $ele ( @$b ) {
+	    $key=&$keyGen( $ele, @_ );
+	    $key =~ s/\\/\\\\/g ;
+	    $key =~ s/\n/\\n/sg ;
+	    print $fhb "$key\n" ;
+	  }
+	  close($fhb);
+	  
+	  open(DIFFPIPE, "diff $minimal $fna $fnb |") or die "_longestCommonSubsequence: Cannot launch diff process. $!" ;
+	  # The diff line numbering begins with 1, but Perl subscripts start with 0
+	  # We follow the diff numbering but substract 1 when assigning to matchVector
+	  $aStart++; $bStart++ ; $aFinish++ ; $bFinish++ ;
+	  while( <DIFFPIPE> ) {
+	    if ( ($alines,$blines) = ( m/^(\d*(?:,\d*)?)?c(\d*(?:,\d*)?)?$/ ) ) {
+	      ($alb,$alf)=split(/,/,$alines);
+	      ($blb,$blf)=split(/,/,$blines);
+	      $alf=$alb unless defined($alf);
+	      $blf=$blb unless defined($blf);
+	      while($aStart < $alb ) {
+		$matchVector->[ -1 + $aStart++ ] = -1 + $bStart++ ;
+	      }
+	      # check for consistency
+	      $bStart==$blb or die "_longestCommonSubsequence: Fatal error in interpreting diff output: Inconsistency in changed sequence";
+	      $aStart=$alf+1;
+	      $bStart=$blf+1;
+	    }
+	    elsif ( ($alb,$blines) = ( m/^(\d*)a(\d*(?:,\d*)?)$/ ) ) {
+	      ($blb,$blf)=split(/,/,$blines);
+	      $blf=$blb unless defined($blf);
+	      while ( $bStart < $blb ) {
+		$matchVector->[ -1 + $aStart++ ] = -1 + $bStart++ ;
+	      }
+	      $aStart==$alb+1 or die "_longestCommonSubsequence: Fatal error in interpreting diff output: Inconsistency in appended sequence near elements $aStart and $bStart";
+	      $bStart=$blf+1;
+	    }
+	    elsif ( ($alines,$blb) = ( m/^(\d*(?:,\d*)?)d(\d*)$/ ) ) {
+	      ($alb,$alf)=split(/,/,$alines);
+	      $alf=$alb unless defined($alf);
+	      while ( $aStart < $alb ) {
+		$matchVector->[ -1 + $aStart++ ] = -1 + $bStart++ ;
+	      }
+	      $bStart==$blb+1 or die "_longestCommonSubsequence: Fatal error in interpreting diff output: Inconsistency in deleted sequence near elements $aStart and $bStart";
+	      $aStart=$alf+1;
+	    }
+	    elsif ( m/^Binary files/ ) {
+	      # if diff reports it is a binary file force --text mode. I do not like
+	      # to always use this option because it is probably only available in GNU diff
+	      open(DIFFPIPE, "diff --text $fna $fnb |") or die "Cannot launch diff process. $!" ;
+	    }
+	    # Default: just skip line
+	  }
+	  while ($aStart <= $aFinish ) {
+	    $matchVector->[ -1 + $aStart++ ] = -1 + $bStart++ ;
+	  }
+	  $bStart==$bFinish+1  or die "_longestCommonSubsequence: Fatal error in interpreting diff output: Inconsistency at end";
+	  close DIFFPIPE;
+	  # check whether a system error has occurred or return status is greater than or equal to 5
+	  if ( $! || ($? >> 8) > 5) {
+	    print STDERR "diff process failed with exit code ", ($? >> 8), " $!\n";
+	    die;
+	  }
+	  unlink $fna,$fnb ;
+	}
+	return wantarray ? @$matchVector : $matchVector;
+}
+
+sub traverse_sequences
+{
+	my $a                 = shift;                                  # array ref
+	my $b                 = shift;                                  # array ref
+	my $callbacks         = shift || {};
+	my $keyGen            = shift;
+	my $matchCallback     = $callbacks->{'MATCH'} || sub { };
+	my $discardACallback  = $callbacks->{'DISCARD_A'} || sub { };
+	my $finishedACallback = $callbacks->{'A_FINISHED'};
+	my $discardBCallback  = $callbacks->{'DISCARD_B'} || sub { };
+	my $finishedBCallback = $callbacks->{'B_FINISHED'};
+	my $matchVector = _longestCommonSubsequence( $a, $b, $keyGen, @_ );
+
+	# Process all the lines in @$matchVector
+	my $lastA = $#$a;
+	my $lastB = $#$b;
+	my $bi    = 0;
+	my $ai;
+
+	for ( $ai = 0 ; $ai <= $#$matchVector ; $ai++ )
+	{
+		my $bLine = $matchVector->[$ai];
+		if ( defined($bLine) )    # matched
+		{
+			&$discardBCallback( $ai, $bi++, @_ ) while $bi < $bLine;
+			&$matchCallback( $ai,    $bi++, @_ );
+		}
+		else
+		{
+			&$discardACallback( $ai, $bi, @_ );
+		}
+	}
+
+	# The last entry (if any) processed was a match.
+	# $ai and $bi point just past the last matching lines in their sequences.
+
+	while ( $ai <= $lastA or $bi <= $lastB )
+	{
+
+		# last A?
+		if ( $ai == $lastA + 1 and $bi <= $lastB )
+		{
+			if ( defined($finishedACallback) )
+			{
+				&$finishedACallback( $lastA, @_ );
+				$finishedACallback = undef;
+			}
+			else
+			{
+				&$discardBCallback( $ai, $bi++, @_ ) while $bi <= $lastB;
+			}
+		}
+
+		# last B?
+		if ( $bi == $lastB + 1 and $ai <= $lastA )
+		{
+			if ( defined($finishedBCallback) )
+			{
+				&$finishedBCallback( $lastB, @_ );
+				$finishedBCallback = undef;
+			}
+			else
+			{
+				&$discardACallback( $ai++, $bi, @_ ) while $ai <= $lastA;
+			}
+		}
+
+		&$discardACallback( $ai++, $bi, @_ ) if $ai <= $lastA;
+		&$discardBCallback( $ai, $bi++, @_ ) if $bi <= $lastB;
+	}
+
+	return 1;
+}
+
+sub traverse_balanced
+{
+	my $a                 = shift;                                  # array ref
+	my $b                 = shift;                                  # array ref
+	my $callbacks         = shift || {};
+	my $keyGen            = shift;
+	my $matchCallback     = $callbacks->{'MATCH'} || sub { };
+	my $discardACallback  = $callbacks->{'DISCARD_A'} || sub { };
+	my $discardBCallback  = $callbacks->{'DISCARD_B'} || sub { };
+	my $changeCallback    = $callbacks->{'CHANGE'};
+	my $matchVector = _longestCommonSubsequence( $a, $b, $keyGen, @_ );
+
+	# Process all the lines in match vector
+	my $lastA = $#$a;
+	my $lastB = $#$b;
+	my $bi    = 0;
+	my $ai    = 0;
+	my $ma    = -1;
+	my $mb;
+
+	while (1)
+	{
+
+		# Find next match indices $ma and $mb
+		do { $ma++ } while ( $ma <= $#$matchVector && !defined $matchVector->[$ma] );
+
+		last if $ma > $#$matchVector;    # end of matchVector?
+		$mb = $matchVector->[$ma];
+
+		# Proceed with discard a/b or change events until
+		# next match
+		while ( $ai < $ma || $bi < $mb )
+		{
+
+			if ( $ai < $ma && $bi < $mb )
+			{
+
+				# Change
+				if ( defined $changeCallback )
+				{
+					&$changeCallback( $ai++, $bi++, @_ );
+				}
+				else
+				{
+					&$discardACallback( $ai++, $bi, @_ );
+					&$discardBCallback( $ai, $bi++, @_ );
+				}
+			}
+			elsif ( $ai < $ma )
+			{
+				&$discardACallback( $ai++, $bi, @_ );
+			}
+			else
+			{
+
+				# $bi < $mb
+				&$discardBCallback( $ai, $bi++, @_ );
+			}
+		}
+
+		# Match
+		&$matchCallback( $ai++, $bi++, @_ );
+	}
+
+	while ( $ai <= $lastA || $bi <= $lastB )
+	{
+		if ( $ai <= $lastA && $bi <= $lastB )
+		{
+
+			# Change
+			if ( defined $changeCallback )
+			{
+				&$changeCallback( $ai++, $bi++, @_ );
+			}
+			else
+			{
+				&$discardACallback( $ai++, $bi, @_ );
+				&$discardBCallback( $ai, $bi++, @_ );
+			}
+		}
+		elsif ( $ai <= $lastA )
+		{
+			&$discardACallback( $ai++, $bi, @_ );
+		}
+		else
+		{
+
+			# $bi <= $lastB
+			&$discardBCallback( $ai, $bi++, @_ );
+		}
+	}
+
+	return 1;
+}
+
+sub LCS
+{
+	my $a = shift;                                           # array ref
+	my $matchVector = _longestCommonSubsequence( $a, @_ );
+	my @retval;
+	my $i;
+	for ( $i = 0 ; $i <= $#$matchVector ; $i++ )
+	{
+		if ( defined( $matchVector->[$i] ) )
+		{
+			push ( @retval, $a->[$i] );
+		}
+	}
+	return wantarray ? @retval : \@retval;
+}
+
+sub diff
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $retval = [];
+	my $hunk   = [];
+	my $discard = sub { push ( @$hunk, [ '-', $_[0], $a->[ $_[0] ] ] ) };
+	my $add = sub { push ( @$hunk, [ '+', $_[1], $b->[ $_[1] ] ] ) };
+	my $match = sub { push ( @$retval, $hunk ) if scalar(@$hunk); $hunk = [] };
+	traverse_sequences( $a, $b,
+		{ MATCH => $match, DISCARD_A => $discard, DISCARD_B => $add }, @_ );
+	&$match();
+	return wantarray ? @$retval : $retval;
+}
+
+sub sdiff
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $retval = [];
+	my $discard = sub { push ( @$retval, [ '-', $a->[ $_[0] ], "" ] ) };
+	my $add = sub { push ( @$retval, [ '+', "", $b->[ $_[1] ] ] ) };
+	my $change = sub {
+		push ( @$retval, [ 'c', $a->[ $_[0] ], $b->[ $_[1] ] ] );
+	};
+	my $match = sub {
+		push ( @$retval, [ 'u', $a->[ $_[0] ], $b->[ $_[1] ] ] );
+	};
+	traverse_balanced(
+		$a,
+		$b,
+		{
+			MATCH     => $match,
+			DISCARD_A => $discard,
+			DISCARD_B => $add,
+			CHANGE    => $change,
+		},
+		@_
+	);
+	return wantarray ? @$retval : $retval;
+}
+
+1;
+}
+import Algorithm::Diff qw(traverse_sequences);
+# End of inserted block for stand-alone version
+
+
+use Getopt::Long ;
+use strict ;
+use utf8 ;
+
+my ($algodiffversion)=split(/ /,$Algorithm::Diff::VERSION);
+
+
+my ($versionstring)=<<EOF ;
+This is LATEXDIFF 0.5  (Algorithm::Diff $Algorithm::Diff::VERSION)
+  (c) 2004-2007 F J Tilmann
+EOF
+
+# Configuration variables: these have to be visible from the subroutines
+my $MINWORDSBLOCK=3; # minimum number of tokens to form an independent block
+                     # shorter identical blocks will be merged to the previous word
+my $FLOATENV='(?:figure|table|plate)[\w\d*@]*' ;   # Environments in which FL variants of defined commands are used
+my $PICTUREENV='(?:picture|DIFnomarkup)[\w\d*@]*' ;   # Environments in which all change markup is removed
+my $MATHENV='(?:equation|displaymath|DOLLARDOLLAR)' ;           # Environments turning on display math mode (code also knows about \[ and \]
+my $MATHREPL='displaymath';  # Environment introducing deleted maths blocks
+my $MATHARRENV='(?:eqnarray|align|gather|multiline|flalign)[*]?' ;           # Environments turning on eqnarray math mode
+my $MATHARRREPL='eqnarray*';  # Environment introducing deleted maths blocks
+my $ARRENV='(?:array|[pbvBV]matrix)'; # Enviroments making arrays in math mode.  The underlining style does not cope well with those - as a result in-text math environments are surrounded by \mbox{ } if any of these commands is used in an inline math block
+my $COUNTERCMD='(?:footnote|part|section|subsection|subsubsection|paragraph|subparagraph)';  # textcmds which are associated with a counter
+                                        # If any of these commands occur in a deleted block
+                                        # they will be succeeded by an \addtocounter{...}{-1}
+                                        # for the associated counter such that the overall numbers
+                                        # should be the same as in the new file
+
+# Markup strings
+# If at all possible, do not change these as parts of the program
+# depend on the actual name (particularly post-processing)
+# At the very least adapt subroutine postprocess to new tokens.
+my $ADDMARKOPEN='\DIFaddbegin ';   # Token to mark begin of appended text
+my $ADDMARKCLOSE='\DIFaddend ';   # Token to mark end of appended text
+my $ADDOPEN='\DIFadd{';  # To mark begin of added text passage
+my $ADDCLOSE='}';        # To mark end of added text passage
+my $ADDCOMMENT='DIF > ';   # To mark added comment line
+my $DELMARKOPEN='\DIFdelbegin ';   # Token to mark begin of deleted text
+my $DELMARKCLOSE='\DIFdelend ';   # Token to mark end of deleted text
+my $DELOPEN='\DIFdel{';  # To mark begin of deleted text passage
+my $DELCLOSE='}';        # To mark end of deleted text passage
+my $DELCMDOPEN='%DIFDELCMD < ';  # To mark begin of deleted commands (must begin with %, i.e., be a comment
+my $DELCMDCLOSE="%%%\n";    # To mark end of deleted commands (must end with a new line)
+my $AUXCMD='%DIFAUXCMD' ; #  follows auxiliary commands put in by latexdiff to make difference file legal
+                          # auxiliary commands must be on a line of their own
+my $DELCOMMENT='DIF < ';   # To mark deleted comment line
+
+
+# main local variables:
+my @TEXTCMDLIST=();  # array containing patterns of commands with text arguments
+my @TEXTCMDEXCL=();  # array containing patterns of commands without text arguments (if a pattern
+                     # matches both TEXTCMDLIST and TEXTCMDEXCL it is excluded)
+my @CONTEXT1CMDLIST=();  # array containing patterns of commands with text arguments (subset of text commands),
+                         # but which cause confusion if used out of context (e.g. \caption). 
+                         # In deleted passages, the command will be disabled but its argument is marked up
+                         # Otherwise they behave exactly like TEXTCMD's 
+my @CONTEXT1CMDEXCL=();  # exclude list for above, but always empty
+my @CONTEXT2CMDLIST=();  # array containing patterns of commands with text arguments, but which fail cause confusion
+                         # if used out of context (e.g. \title). They and their arguments will be disabled in deleted
+                         # passages
+my @CONTEXT2CMDEXCL=();  # exclude list for above, but always empty
+
+my @SAFECMDLIST=();  # array containing patterns of safe commands (which do not break when in the argument of DIFadd or DIFDEL)
+my @SAFECMDEXCL=();
+
+my ($i,$j,$l);
+my ($old,$new);
+my ($line);
+my ($newpreamble,$oldpreamble);
+my (@newpreamble,@oldpreamble,@diffpreamble,@diffbody);
+my ($latexdiffpreamble);
+my ($oldbody, $newbody, $diffbo);
+my ($oldpost, $newpost);
+my ($diffall);
+# Option names
+my ($type,$subtype,$floattype,$config,$preamblefile,$encoding,
+    $showpreamble,$showsafe,$showtext,$showconfig,$showall,
+    $replacesafe,$appendsafe,$excludesafe,
+    $replacetext,$appendtext,$excludetext,
+    $replacecontext1,$appendcontext1,
+    $replacecontext2,$appendcontext2,
+    $help,$verbose,$version,$ignorewarnings,$allowspaces,$flatten,$debug);
+my (@configlist,
+    @appendsafelist,@excludesafelist,
+    @appendtextlist,@excludetextlist,
+    @appendcontext1list,@appendcontext2list,
+    @packagelist);
+my ($assign,@config);
+# Hash where keys corresponds to the names of  all included packages (including the documentclass as another package
+# the optional arguments to the package are the values of the hash elements
+my ($pkg,%packages);
+# Defaults
+$type='UNDERLINE';
+$subtype='SAFE';
+$floattype='FLOATSAFE';
+
+$verbose=0;
+$debug=1; 
+# define character properties
+sub IsNonAsciiPunct { return <<'END'    # Unicode punctuation but excluding ASCII punctuation
++utf8::IsPunct
+-utf8::IsASCII
+END
+}
+sub IsNonAsciiS { return <<'END'       # Unicode symbol but excluding ASCII
++utf8::IsS
+-utf8::IsASCII
+END
+}
+
+
+
+  my %verbhash;
+
+Getopt::Long::Configure('bundling');
+GetOptions('type|t=s' => \$type, 
+	   'subtype|s=s' => \$subtype, 
+	   'floattype|f=s' => \$floattype, 
+	   'config|c=s' => \@configlist,
+	   'preamble|p=s' => \$preamblefile,
+	   'encoding|e=s' => \$encoding,
+	   'exclude-safecmd|A=s' => \@excludesafelist,
+	   'replace-safecmd=s' => \$replacesafe,
+	   'append-safecmd|a=s' => \@appendsafelist,
+	   'exclude-textcmd|X=s' => \@excludetextlist,
+	   'replace-textcmd=s' => \$replacetext,
+	   'append-textcmd|x=s' => \@appendtextlist,
+	   'replace-context1cmd=s' => \$replacecontext1,
+	   'append-context1cmd=s' => \@appendcontext1list,
+	   'replace-context2cmd=s' => \$replacecontext2,
+	   'append-context2cmd=s' => \@appendcontext2list,
+	   'show-preamble' => \$showpreamble,
+	   'show-safecmd' => \$showsafe,
+	   'show-textcmd' => \$showtext,
+	   'show-config' => \$showconfig,
+	   'show-all' => \$showall,
+           'packages=s' => \@packagelist,
+	   'verbose|V' => \$verbose,
+	   'ignore-warnings' => \$ignorewarnings,
+	   'allow-spaces' => \$allowspaces,
+	   'flatten' => \$flatten,
+	   'version' => \$version,
+	   'help|h|H' => \$help);
+
+if ( $help ) {
+  usage() ;
+}
+
+
+if ( $version ) {
+  die $versionstring ; 
+}
+
+print STDERR $versionstring if $verbose; 
+
+if (defined($showall)){
+  $showpreamble=$showsafe=$showtext=$showconfig=1;
+}
+
+# setting extra preamble commands
+if (defined($preamblefile)) {
+  $latexdiffpreamble=join "\n",(extrapream($preamblefile),"");
+} else {
+  $latexdiffpreamble=join "\n",(extrapream($type,$subtype,$floattype),"");
+}
+
+# setting up @SAFECMDLIST and @SAFECMDEXCL
+if (defined($replacesafe)) {
+  init_regex_arr_ext(\@SAFECMDLIST,$replacesafe);
+} else {
+  init_regex_arr_data(\@SAFECMDLIST, "SAFE COMMANDS");
+}
+foreach $appendsafe ( @appendsafelist ) {
+  init_regex_arr_ext(\@SAFECMDLIST, $appendsafe);
+}
+foreach $excludesafe ( @excludesafelist ) {
+  init_regex_arr_ext(\@SAFECMDEXCL, $excludesafe);
+}
+
+# Special: treat all cite commands as safe except in UNDERLINE and FONTSTRIKE mode
+# (there is a conflict between citation and ulem package, see
+# package documentation)
+if ( uc($type) ne "UNDERLINE" && uc($type) ne "FONTSTRIKE" && uc($type) ne "CULINECHBAR" ) {
+  push (@SAFECMDLIST, qr/^cite.*$/);
+}
+
+# setting up @TEXTCMDLIST and @TEXTCMDEXCL
+if (defined($replacetext)) {
+  init_regex_arr_ext(\@TEXTCMDLIST,$replacetext);
+} else {
+  init_regex_arr_data(\@TEXTCMDLIST, "TEXT COMMANDS");
+}
+foreach $appendtext ( @appendtextlist ) {
+  init_regex_arr_ext(\@TEXTCMDLIST, $appendtext);
+}
+foreach $excludetext ( @excludetextlist ) {
+  init_regex_arr_ext(\@TEXTCMDEXCL, $excludetext);
+}
+
+
+# setting up @CONTEXT1CMDLIST ( @CONTEXT1CMDEXCL exist but is always empty )
+if (defined($replacecontext1)) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST,$replacecontext1);
+} else {
+  init_regex_arr_data(\@CONTEXT1CMDLIST, "CONTEXT1 COMMANDS");
+}
+foreach $appendcontext1 ( @appendcontext1list ) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST, $appendcontext1);
+}
+
+
+# setting up @CONTEXT2CMDLIST ( @CONTEXT2CMDEXCL exist but is always empty )
+if (defined($replacecontext2)) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST,$replacecontext2);
+} else {
+  init_regex_arr_data(\@CONTEXT2CMDLIST, "CONTEXT2 COMMANDS");
+}
+foreach $appendcontext2 ( @appendcontext2list ) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST, $appendcontext2);
+}
+
+
+
+
+# setting configuration variables
+@config=();
+foreach $config ( @configlist ) {
+  if (-f $config ) {
+    open(FILE,$config) or die ("Couldn't open configuration file $config: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@config,$_);
+    }
+    close(FILE);
+  }
+  else {
+#    foreach ( split(",",$config) ) {
+#      push @config,$_;
+#    }
+     push @config,split(",",$config)
+  }
+}
+foreach $assign ( @config ) {
+  $assign=~ m/\s*(\w*)\s*=\s*(\S*)\s*$/ or die "Illegal assignment $assign in configuration list (must be variable=value)";  
+  if ( $1 eq "MINWORDSBLOCK" ) { $MINWORDSBLOCK = $2; }
+  elsif ( $1 eq "FLOATENV" ) { $FLOATENV = $2 ; }
+  elsif ( $1 eq "PICTUREENV" ) { $PICTUREENV = $2 ; }
+  elsif ( $1 eq "MATHENV" ) { $MATHENV = $2 ; }
+  elsif ( $1 eq "MATHREPL" ) { $MATHREPL = $2 ; }
+  elsif ( $1 eq "MATHARRENV" ) { $MATHARRENV = $2 ; }
+  elsif ( $1 eq "MATHARRREPL" ) { $MATHARRREPL = $2 ; }
+  elsif ( $1 eq "ARRENV" ) { $ARRENV = $2 ; }
+  elsif ( $1 eq "COUNTERCMD" ) { $COUNTERCMD = $2 ; }
+  else { die "Unknown variable $1 in assignment.";}
+}
+
+
+foreach $pkg ( @packagelist ) {
+  map { $packages{$_}="" } split(/,/,$pkg) ;
+}
+
+if ($showpreamble) {
+  print "\nPreamble commands:\n";
+  print $latexdiffpreamble ;
+}
+
+if ($showsafe) {
+  print "\nCommands safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE (unless excluded):\n";
+  print_regex_arr(@SAFECMDLIST);
+  print "\nCommands not safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE :\n";
+  print_regex_arr(@SAFECMDEXCL);
+}
+
+if ($showtext) {
+  print "\nCommands with last argument textual (unless excluded) and safe in every context:\n";
+  print_regex_arr(@TEXTCMDLIST);
+  print "\nContext1 commands (last argument textual, command will be disabled in deleted passages, last argument will be shown as plain text):\n";
+  print_regex_arr(@CONTEXT1CMDLIST);
+  print "\nContext2 commands (last argument textual, command ant its argument will be disabled in deleted passages):\n";
+  print_regex_arr(@CONTEXT2CMDLIST);  
+  print "\nExclude list of Commands with last argument not textual (overrides patterns above):\n";
+  print_regex_arr(@TEXTCMDEXCL);
+}
+
+if ($showconfig) {
+  print "Configuration variables:\n";
+  print "MINWORDSBLOCK=$MINWORDSBLOCK\n";
+  print "FLOATENV=$FLOATENV\n";
+  print "PICTUREENV=$PICTUREENV\n";
+  print "MATHENV=$MATHENV\n";
+  print "MATHREPL=$MATHREPL\n";
+  print "MATHARRENV=$MATHARRENV\n";
+  print "MATHARRREPL=$MATHARRREPL\n";
+  print "ARRENV=$ARRENV\n";
+  print "COUNTERCMD=$COUNTERCMD\n";
+}
+if ($showconfig || $showtext || $showsafe || $showpreamble) {
+  exit 0; }
+if ( @ARGV != 2 ) { 
+  print STDERR "2 and only 2 non-option arguments required.  Write latexdiff -h to get help\n";
+  exit(2);
+}
+
+# Are extra spaces between command arguments permissible?
+my $extraspace;
+if ($allowspaces) {
+  $extraspace='\s*'; 
+} else {
+  $extraspace='';
+}
+
+# append context lists to text lists (as text property is implied)
+push @TEXTCMDLIST, @CONTEXT1CMDLIST;
+push @TEXTCMDLIST, @CONTEXT2CMDLIST;
+
+
+# Patterns. These are used by some of the subroutines, too
+# I can only define them down here because value of extraspace depends on an option
+  my $pat0 = '(?:[^{}]|\\\{|\\\})*';
+  my $pat1 = '(?:[^{}]|\\\{|\\\}|\{'.$pat0.'\})*';
+  my $pat2 = '(?:[^{}]|\\\{|\\\}|\{'.$pat1.'\})*'; # 
+  my $pat3 = '(?:[^{}]|\\\{|\\\}|\{'.$pat2.'\})*';
+  my $pat4 = '(?:[^{}]|\\\{|\\\}|\{'.$pat3.'\})*';
+  my $brat0 = '(?:[^\[\]]|\\\[|\\\])*'; 
+
+  my $quotemarks = '(?:\'\')|(?:\`\`)';
+  my $punct='[0.,\/\'\`:;\"\?\(\)\[\]!~\p{IsNonAsciiPunct}\p{IsNonAsciiS}]';
+  my $number='-?\d*\.\d*';
+  my $mathpunct='[+=<>\-\|]';
+  my $and = '&';
+  my $coords= '[\-.,\s\d]*';
+# word: sequence of letters or accents followed by letter
+  my $word='(?:[-\w\d*]|\\\\[\"\'\`~^][A-Za-z\*])+';
+  my $cmdleftright='\\\\(?:left|right)\s*(?:[()\[\]|]|\\\\(?:[|{}]|\w+))';
+
+  my $cmdoptseq='\\\\[\w\d\*]+'.$extraspace.'(?:(?:\['.$brat0.'\]|\{'. $pat4 . '\}|\(' . $coords .'\))'.$extraspace.')*';
+  my $oneletcmd='\\\\.(?:\['.$brat0.'\]|\{'. $pat4 . '\})*';
+  my $math='\$(?:[^$]|\\\$)*?\$|\\\\[(].*?\\\\[)]';
+#  my $math='\$(?:[^$]|\\\$)*\$';
+  my $comment='%.*?\n';
+  my $pat=qr/(?:\A\s*)?(?:${and}|${quotemarks}|${number}|${word}|$cmdleftright|${cmdoptseq}|${math}|${oneletcmd}|${comment}|${punct}|${mathpunct}|\{|\})\s*/ ;
+
+
+
+# now we are done setting up and can start working   
+my ($oldfile, $newfile) = @ARGV;
+
+$encoding=guess_encoding($newfile) unless defined($encoding);
+
+$encoding = "utf8" if $encoding =~ m/^utf8/i ;
+if (lc($encoding) eq "utf8" ) {
+  binmode(STDOUT, ":utf8");
+  binmode(STDERR, ":utf8");
+}
+
+$old=read_file_with_encoding($oldfile,$encoding);
+$new=read_file_with_encoding($newfile,$encoding);
+
+
+
+
+# reset time
+exetime(1);
+($oldpreamble,$oldbody,$oldpost)=splitdoc($old,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+($newpreamble,$newbody,$newpost)=splitdoc($new,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+if ($flatten) {
+  $oldbody=flatten($oldbody,$oldpreamble,$oldfile,$encoding);
+  $newbody=flatten($newbody,$newpreamble,$newfile,$encoding);
+}
+
+if ( length $oldpreamble && length $newpreamble ) {
+  @oldpreamble = split /\n/, $oldpreamble;
+  @newpreamble = split /\n/, $newpreamble;
+  
+  %packages=list_packages(@newpreamble) unless %packages;
+  if (defined $packages{"hyperref"} ) {
+    print STDERR "hyperref package detected.\n" if $verbose ;
+    $latexdiffpreamble =~ s/\{\\DIFadd\}/{\\DIFaddtex}/g;
+    $latexdiffpreamble =~ s/\{\\DIFdel\}/{\\DIFdeltex}/g;
+    $latexdiffpreamble .= join "\n",(extrapream("HYPERREF"),"");
+  }
+  # insert dummy first line such that line count begins with line 1 (rather than perl's line 0) - just so that line numbers inserted by linediff are correct
+  unshift @newpreamble,'';
+  unshift @oldpreamble,'';
+  print STDERR "Differencing preamble.\n" if $verbose;
+  @diffpreamble = linediff(\@oldpreamble, \@newpreamble);
+  # remove dummy line again
+  shift @diffpreamble; 
+  push @diffpreamble,$latexdiffpreamble;
+  push @diffpreamble,'\begin{document}';
+}
+elsif ( !length $oldpreamble && !length $newpreamble ) {
+  @diffpreamble=();
+} else {
+  print STDERR "Either both texts must have preamble or neither text must have the preamble.\n";
+  exit(2);
+}
+
+if (defined $packages{"amsmath"} ) {
+  print STDERR "amsmath package detected.\n" if $verbose ;
+  $MATHARRREPL='align*';
+}
+
+print STDERR "Preprocessing body.  " if $verbose;
+my ($oldleadin,$newleadin)=preprocess($oldbody,$newbody);
+
+
+# run difference algorithm
+@diffbody=bodydiff($oldbody, $newbody);
+$diffbo=join("",@diffbody);
+print STDERR "(",exetime()," s)\n","Postprocessing body. \n " if $verbose;
+postprocess($diffbo);
+$diffall =join("\n",@diffpreamble) ;
+$diffall .= "$newleadin$diffbo" ;
+$diffall .= "\\end{document}$newpost" if length $newpreamble ;
+if ( lc($encoding) ne "utf8" && lc($encoding) ne "ascii" ) {
+  print STDERR "Encoding output file to $encoding\n" if $verbose;
+  $diffall=Encode::encode($encoding,$diffall);
+  binmode STDOUT;
+}
+print $diffall;
+
+
+print STDERR "(",exetime()," s)\n","Done.\n" if $verbose;
+
+
+
+## guess_encoding(filename)
+## reads the first 20 lines of filename and looks for call of inputenc package
+## if found, return the option of this package (encoding), otherwise return ascii
+sub guess_encoding {
+  my ($filename)=@_;
+  my ($i,$enc);
+  open (FH, $filename) or die("Couldn't open $filename: $!");
+  $i=0;
+  while (<FH>) {
+    next if /^\s*%/;    # skip comment lines
+    if (m/\\usepackage\[(\w*?)\]\{inputenc\}/) {
+      close(FH);
+      return($1);
+    }
+    last if (++$i > 20 ); # scan at most 20 non-comment lines
+  }
+  close(FH);
+  return("ascii");
+}
+
+
+sub read_file_with_encoding {
+  my ($output);
+  my ($filename, $encoding) = @_;
+
+  if (lc($encoding) eq "utf8" ) {
+    open (FILE, "<:utf8",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } elsif ( lc($encoding) eq "ascii") {
+    open (FILE, $filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } else {
+    require Encode;
+    open (FILE, "<",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+    print STDERR "Converting $filename from $encoding to utf8\n" if $verbose;
+    $output=Encode::decode($encoding,$output);
+  }
+  close FILE;
+  return $output;
+}
+
+# %packages=list_packages(@preamble)
+# scans the arguments for \documentclass and \usepackage statements and constructs a hash
+# whose keys are the included packages, and whose values are the associated optional arguments
+sub list_packages {
+  my (@preamble)=@_;
+  my %packages=();
+  foreach $line ( @preamble ) {
+    # get rid of comments
+    $line=~s/(?<!\\)%.*$// ;
+    if ( $line =~ m/\\(?:documentclass|usepackage)(?:\[(.+?)\])?\{(.*?)\}/ ) {
+#      print STDERR "Found something: |$line|\n";
+      if (defined($1)) {
+	$packages{$2}=$1;
+      } else {
+	$packages{$2}="";
+      }
+    }
+  }
+  return (%packages);
+}
+
+# flatten($text,$preamble,$filename,$encoding)
+# expands \input and \include commands within text
+# premable is scanned for includeonly commands
+# encoding is the encoding
+sub flatten {
+  my ($text,$preamble,$filename,$encoding)=@_;
+  my ($includeonly,$dirname,$fname,$newpage,$replacement);
+  require File::Basename ; 
+  require File::Spec ; 
+  $dirname = File::Basename::dirname($filename);
+
+  if ( ($includeonly) = ($preamble =~ m/\\includeonly{(.*?)}/ ) ) {
+    $includeonly =~ s/,/|/g;
+  } else {
+    $includeonly = '.*?';
+  }
+
+  print STDERR "DEBUG: includeonly $includeonly\n";
+
+  $text=~s/\\input{(.*?)}|\\include{(${includeonly}(?:\.tex)?)}/{ 
+	    $fname = $1 if defined($1)  ;
+	    $fname = $2 if defined($2) ;       
+            #      # add tex extension unless there is a three letter extension already 
+            $fname .= ".tex" unless $fname =~ m|\.\w{3}|;
+            print STDERR "Include file $fname\n" if $verbose;
+            print STDERR "DEBUG looking for file ",File::Spec->catfile($dirname,$fname), "\n";
+            # content of file becomes replacement value, add \newpage if the command was include
+            $replacement=read_file_with_encoding(File::Spec->catfile($dirname,$fname), $encoding) or die
+                "Couldn't find file ",File::Spec->catfile($dirname,$fname),": $!";
+	    $newpage=(defined($2)? " \\newpage " : "") ;
+	    "$newpage$replacement$newpage";
+          }/exg;
+
+  return($text);
+}
+
+
+# print_regex_arr(@arr)
+# prints regex array without x-ism expansion put in by pearl to stdout
+sub print_regex_arr {
+  my $dumstring;
+  $dumstring = join(" ",@_);     # PERL generates string (?-xism:^ref$) for quoted refex ^ref$
+  $dumstring =~ s/\(\?-xism:\^(.*?)\$\)/$1/g;   # remove string and ^,$ marks before output
+  print $dumstring,"\n";
+}
+
+
+# @lines=extrapream($type)
+# reads line from appendix (end of file after __END__ token)
+sub extrapream {
+  my $type;
+  my @retval=("%DIF PREAMBLE EXTENSION ADDED BY LATEXDIFF") ;
+  my ($copy);
+
+  while (@_) {
+    $copy=0;
+    $type=shift ;
+    if ( -f $type ) {
+      open (FILE,$type) or die "Cannot open preamble file $type: $!";
+      print STDERR "Reading preamble file $type\n" if $verbose ;
+      while (<FILE>) {
+	chomp ;
+	if ( $_ =~ m/%DIF PREAMBLE/ ) {
+	  push (@retval,"$_"); 
+	} else {
+	  push (@retval,"$_ %DIF PREAMBLE"); 
+	}
+      }
+    } 
+    else {    # not (-f $type)
+      $type=uc($type);   # upcase argument
+      print STDERR "Preamble Internal Type $type\n" if $verbose;
+      while (<DATA>) {
+	if ( m/^%DIF $type/ ) {
+	  $copy=1; }
+	elsif ( m/^%DIF END $type/ ) {
+	  last; }
+	chomp;
+	push (@retval,"$_ %DIF PREAMBLE") if $copy;
+      }
+      if ( $copy == 0 ) {
+	print STDERR "\nPreamble style $type not implemented.\n";
+        print STDERR "Write latexdiff -h to get help with available styles\n";
+        exit(2);
+      }
+      seek DATA,0,0;    # rewind DATA handle to file begin
+    }
+  }
+  push (@retval,"%DIF END PREAMBLE EXTENSION ADDED BY LATEXDIFF")  ;
+  return @retval;
+}
+
+
+# ($part1,$part2,$part3)=splitdoc($text,$word1,$word2)
+# splits $text into 3 parts at $word1 and $word2.
+# if neither $word1 nor $word2 exist, $part1 and $part3 are empty, $part2 is $text
+# If only $word1 or $word2 exist but not the other, output an error message.
+
+# NB this version avoids $` and $' for performance reason although it only makes a tiny difference
+# (in one test gain a tenth of a second for a 30s run)
+sub splitdoc {
+  my ($text,$word1,$word2)=@_;
+  my ($part1,$part2,$part3)=("","","");
+  my ($rest,$pos);
+
+  if ( $text =~ m/(^[^%]*)($word1)/mg ) {
+    $pos=pos $text;
+    $part1=substr($text,0,$pos-length($2));
+    $rest=substr($text,$pos);
+    if ( $rest =~ m/(^[^%]*)($word2)/mg ) {
+      $pos=pos $rest;
+      $part2=substr($rest,0,$pos-length($2));
+      $part3=substr($rest,$pos);
+    } 
+    else {
+      die "$word1 and $word2 not in the correct order or not present as a pair." ;
+    }
+  } else {
+    $part2=$text;
+    die "$word2 present but not $word1." if ( $text =~ m/(^[^%]*)$word2/ms );
+  }
+  return ($part1,$part2,$part3);
+}
+
+
+
+
+
+# bodydiff($old,$new)
+sub bodydiff {
+  my ($oldwords, $newwords) = @_;
+  my @retwords;
+
+  print STDERR "(",exetime()," s)\n","Splitting into latex tokens \n" if $verbose;
+  print STDERR "Parsing $oldfile \n" if $verbose;
+  my @oldwords = splitlatex($oldwords);
+  print STDERR "Parsing $newfile \n" if $verbose;
+  my @newwords = splitlatex($newwords);
+  my $token;
+
+  print STDERR "(",exetime()," s)\n","Pass 1: Expanding text commands and merging isolated identities with changed blocks  " if $verbose;
+  pass1(\@oldwords, \@newwords);
+
+
+  print STDERR "(",exetime()," s)\n","Pass 2: inserting DIF tokens and mark up.  " if $verbose;
+
+  @retwords=pass2(\@oldwords, \@newwords);
+
+  return(@retwords);
+}
+
+
+
+
+# @words=splitlatex($string)
+# split string according to latex rules
+# Each element of words is either
+# a word (including trailing spaces and punctuation)
+# a latex command
+sub splitlatex {
+  my ($string) = @_ ;
+  my @retval=($string =~ m/$pat/osg);  
+
+  if (length($string) != length(join("",@retval))) {
+    print STDERR "\nWARNING: Inconsistency in length of input string and parsed string:\n     This often indicates faulty or non-standard latex code.\n     In many cases you can ignore this and the following warning messages.\n Note that character numbers in the following are counted beginning after \\begin{document} and are only approximate." unless $ignorewarnings;
+    print STDERR "DEBUG Original length ",length($string),"  Parsed length ",length(join("",@retval)),"\n" if $debug;
+    print STDERR "DEBUG Input string:  |$string|\n" if (length($string)<500) && $debug;
+    print STDERR "DEBUG Token parsing: |",join("+",@retval),"|\n" if (length($string)<500) && $debug ;
+    @retval=();
+    # slow way only do this if other m//sg method fails
+    my $last = 0;
+    while ( $string =~ m/$pat/osg ) {
+      my $match=$&;
+      if ($last + length $& != pos $string  ) {
+	my $pos=pos($string);
+	my $offset=30<$last ? 30 : $last;
+	my $dum=substr($string,$last-$offset,$pos-$last+2*$offset);
+	my $dum1=$dum;
+	my $cnt=$#retval;
+	my $i;
+	$dum1 =~ s/\n/ /g;
+	unless ($ignorewarnings) {
+	  print STDERR "\n$dum1\n";
+	  print STDERR " " x 30,"^" x ($pos-$last)," " x 30,"\n";
+	  print STDERR "Missing characters near word " . (scalar @retval) . " character index: " . $last . "-" .  pos($string) . " Length: " . length($match) . " Match: |$match| (expected match marked above).\n";
+	}
+	  # put in missing characters `by hand'
+	push (@retval, substr($dum,$offset,$pos-$last-length($match)));
+#       Note: there seems to be a bug in substr with utf8 that made the following line output substr which were too long,
+#             using dum instead appears to work
+#	push (@retval, substr($string,$last, pos($string)-$last-length($match)));
+      }
+      push (@retval, $match);
+      $last=pos $string;
+    }
+
+  }
+  return @retval;
+}
+
+
+# pass1( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.
+# Where an common-subsequence block is flanked by deleted or appended blocks, 
+# and is shorter than $MINWORDSBLOCK words it is appended
+# to the last deleted or appended word.  If the block contains tokens other than words 
+# or punctuation it is not merged.
+# Deleted or appended block consisting of words and safe commands only are
+# also merged, to prevent break-up in pass2 (after previous isolated words have been removed)
+# If there are commands with textual arguments (e.g. \caption) both in corresponding 
+# appended and deleted blocks split them such that the command and opening bracket 
+# are one token, then the rest is split up following standard rules, and the closing 
+# bracket is a separate token, ie. turn
+# "\caption{This is a textual argument}" into 
+# ("\caption{","This ","is ","a ","textual ","argument","}")
+# No return value.  Destructively changes sequences
+sub pass1 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $len1 = scalar @$seq1;
+  my $len2 = scalar @$seq2;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;   #'
+
+  my ($last1,$last2)=(-1,-1) ;
+  my $cnt=0;
+  my $block=[];
+  my $addblock=[];
+  my $delblock=[];
+  my $todo=[];
+  my $instruction=[];
+  my $i;
+  my (@delmid,@addmid,@dummy);
+
+  my ($addcmds,$delcmds,$matchindex);
+  my ($addtextblocks,$deltextblocks);
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $adddiscard = sub {
+                      if ($cnt > 0 ) {
+			$matblkcnt++;
+			# just after an unchanged block 
+#			print STDERR "Unchanged block $cnt, $last1,$last2 \n";
+                        if ($cnt < $MINWORDSBLOCK 
+			    && $cnt==scalar (
+				     grep { /^$wpat/ || ( /^\\([\w\d\*]+)((?:\[$brat0\]|\{$pat4\})*)/o 
+							   && iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+							   && scalar(@dummy=split(" ",$2))<3 ) }
+					     @$block) )  {
+			  # merge identical blocks shorter than $MINWORDSBLOCK 
+			  # and only containing ordinary words
+			  # with preceding different word
+			  # We cannot carry out this merging immediately as this
+			  # would change the index numbers of seq1 and seq2 and confuse
+			  # the algorithm, instead we store in @$todo where we have to merge
+                          push(@$todo, [ $last1,$last2,$cnt,@$block ]);
+			}
+			$block = []; 
+			$cnt=0; $last1=-1; $last2=-1;
+		      }
+		    };
+  my $discard=sub { $deltokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$delblock,[ $seq1->[$_[0]],$_[0] ]);
+		    $last1=$_[0] };		      
+
+  my $add =   sub { $addtokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$addblock,[ $seq2->[$_[1]],$_[1] ]);
+		    $last2=$_[1] };		      
+
+  my $match = sub { $mattokcnt++;
+                    if ($cnt==0) {   # first word of matching sequence after changed sequence or at beginning of word sequence
+		      $deltextblocks = extracttextblocks($delblock); 
+		      $delblkcnt++ if scalar @$delblock;
+		      $addtextblocks = extracttextblocks($addblock);
+		      $addblkcnt++ if scalar @$addblock;
+
+		      $delcmds = extractcommands($delblock);
+      		      $addcmds = extractcommands($addblock);
+		      # keygen(third argument of _longestCommonSubsequence) implies to sort on command (0th elements of $addcmd elements)
+		      # the calling format for longestCommonSubsequence has changed between versions of
+		      # Algorithm::Diff so we need to check which one we are using
+		      if ( $algodiffversion  > 1.15 ) {
+			### Algorithm::Diff 1.19
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, 0, sub { $_[0]->[0] } );
+		      } else {
+			### Algorithm::Diff 1.15	
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, sub { $_[0]->[0] } );
+		      }
+
+		      for ($i=0 ; $i<=$#$matchindex ; $i++) {
+			if (defined($matchindex->[$i])){
+			  $j=$matchindex->[$i];
+			  @delmid=splitlatex($delcmds->[$i][3]);
+			  @addmid=splitlatex($addcmds->[$j][3]);
+			  while (scalar(@$deltextblocks)  && $deltextblocks->[0][0]<$delcmds->[$i][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$deltextblocks) };
+			    push(@$todo, [$index,-1,$cnt,@$block]);
+			  }
+			  push(@$todo, [ $delcmds->[$i][1],-1,-1,$delcmds->[$i][2],@delmid,$delcmds->[$i][4]]);
+
+			  while (scalar(@$addtextblocks) && $addtextblocks->[0][0]<$addcmds->[$j][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			    push(@$todo, [-1,$index,$cnt,@$block]);
+			  }
+			  push(@$todo, [ -1,$addcmds->[$j][1],-1,$addcmds->[$j][2],@addmid,$addcmds->[$j][4]]);
+			}
+		      }
+		      # mop up remaining textblocks
+		      while (scalar(@$deltextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$deltextblocks) } ;
+			push(@$todo, [$index,-1,$cnt,@$block]);
+		      }
+		      while (scalar(@$addtextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			push(@$todo, [-1,$index,$cnt,@$block]);
+		      }
+		      
+		      $addblock=[];
+		      $delblock=[];
+		    }
+		    push(@$block,$seq2->[$_[1]]);  
+		    $cnt++  };
+
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+
+
+  # now carry out the merging/splitting.  Refer to elements relative from 
+  # the end (with negative indices) as these offsets don't change before the instruction is executed
+  # cnt>0: merged small unchanged groups with previous changed blocks
+  # cnt==-1: split textual commands into components
+  foreach $instruction ( @$todo) {
+    ($last1,$last2,$cnt,@$block)=@$instruction ;
+    if ($cnt>=0) {
+      splice(@$seq1,$last1-$len1,1+$cnt,join("",$seq1->[$last1-$len1],@$block)) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1+$cnt,join("",$seq2->[$last2-$len2],@$block)) if $last2>=0;
+    } else {
+      splice(@$seq1,$last1-$len1,1,@$block) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1,@$block) if $last2>=0;
+    }
+  }
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens in $matblkcnt blocks.\n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+}
+
+
+# extracttextblocks(\@blockindex)
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [[ $index, $textblock, $cnt ], ..
+# where $index index of block to be merged
+#       $textblock contains all the words to be merged with the word at $index (but does not contain this word)
+#       $cnt   is length of block
+#
+# requires: iscmd
+#
+sub extracttextblocks { 
+  my $block=shift;
+  my ($i,$token,$index);
+  my $textblock=[];
+  my $last=-1;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;  #'
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # store pure text blocks
+    if ($token =~ /$wpat/ ||  ( $token =~/^\\([\w\d\*]+)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*)/o 
+				&& iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+				&& !iscmd($1,\@TEXTCMDLIST,\@TEXTCMDEXCL))) {
+      # we have text or a command which can be treated as text
+      if ($last<0) {
+	# new pure-text block
+	$last=$index;
+      } else {
+	# add to pure-text block
+	push(@$textblock, $token); 
+      }
+    } else {
+      # it is not text
+      if (scalar(@$textblock)) {
+	push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+      }
+      $textblock=[];
+      $last=-1;
+    }
+  }
+  # finish processing a possibly unfinished block before returning
+  if (scalar(@$textblock)) {
+    push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+  }
+  return($retval)
+}
+
+
+
+# extractcommands( \@blockindex )
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [ [ "\cmd1", index, "\cmd1[optarg]{arg1}{", "arg2" ,"} " ],.. 
+# where index is just taken from input array 
+# command must have a textual argument as last argument 
+# 
+# requires: iscmd 
+# 
+sub extractcommands { 
+  my $block=shift;
+  my ($i,$token,$index,$cmd,$open,$mid,$closing);
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # check if token is an alphanumeric command sequence with at least one non-optional argument
+    # \cmd[...]{...}{last argument}  
+    # Capturing in the following results in these associations
+    # $1: \cmd[...]{...}{
+    # $2: \cmd
+    # $3: last argument
+    # $4: }  + trailing spaces
+    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	 && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL) ) {
+      #      push(@$retval,[ $2,$index,$1,$3,$4 ]);
+      ($cmd,$open,$mid,$closing) = ($2,$1,$3,$4) ;
+      $closing =~ s/\}/\\RIGHTBRACE/ ;
+      push(@$retval,[ $cmd,$index,$open,$mid,$closing ]);
+    }
+  }
+  return $retval;
+}
+
+# iscmd($cmd,\@regexarray,\@regexexcl) checks
+# return 1 if $cmd matches any of the patterns in the 
+# array $@regexarray, and none of the patterns in \@regexexcl, otherwise return 0
+sub iscmd {
+  my ($cmd,$regexar,$regexexcl)=@_;
+  my ($ret)=0;
+  foreach $pat ( @$regexar ) {
+    if ( $cmd =~ m/^${pat}$/ ) {
+      $ret=1 ; 
+      last;
+    }
+  }
+  return 0 unless $ret;
+  foreach $pat ( @$regexexcl ) {
+    return 0 if ( $cmd =~ m/^${pat}$/ );
+  }
+  return 1;
+}
+
+
+# pass2( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.  
+# Mark begin and end of deleted and appended sequences with tags $DELOPEN and $DELCLOSE
+# and $ADDOPEN and $ADDCLOSE, respectively, however exclude { } & and all comands, unless
+# they match an element of the whitelist (SAFECMD)
+# For words in TEXTCMD but not in SAFECMD, enclose interior with $ADDOPEN and $ADDCLOSE brackets
+# Deleted comment lines are marked with %DIF < 
+# Added comment lines are marked with %DIF > 
+sub pass2 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $retval = [];
+  my $delhunk   = [];
+  my $addhunk   = [];
+
+  my $discard = sub { $deltokcnt++;
+                      push ( @$delhunk, $seq1->[$_[0]]) };
+
+  my $add = sub { $addtokcnt++;
+                  push ( @$addhunk, $seq2->[$_[1]]) };
+
+  my $match = sub { $mattokcnt++;
+		    if ( scalar @$delhunk ) {
+                      $delblkcnt++;
+		      # mark up changes, but comment out commands
+                      push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk);
+		      $delhunk = [];
+		    }
+                    if ( scalar @$addhunk ) {
+                      $addblkcnt++;
+                      # we mark up changes, but simply quote commands
+                      push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk);
+		      $addhunk = [];
+		    }
+		    push(@$retval,$seq2->[$_[1]]) };
+ 
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  # clear up unprocessed hunks
+  push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk) if scalar @$delhunk;
+  push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk) if scalar @$addhunk;
+
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens. \n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+
+  return(@$retval);
+}
+
+# marktags($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,\@block)
+# returns ($openmark,$open,$block,$close,$closemark) if @block only contains no commands (except white-listed ones),
+# braces, ampersands, or comments
+# mark comments with $comment
+# exclude all other exceptions from scope of open, close like this
+# ($openmark, $open,...,$close, $opencomd,command, command,$closecmd, $open, ..., $close, $closemark)
+# If $opencmd begins with "%" marktags assumes it is operating on a deleted block, otherwise on an added block
+sub marktags {
+  my ($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,$block)=@_;
+  my $word;
+  my (@argtext);
+  my $retval=[];
+  my $noncomment=0;
+  my $cmd=-1;    # -1 at beginning 0: last token written is a ordinary word 
+                 # 1: last token written is a command
+                # for keeping track whether we are just in a command sequence or in a word sequence
+  my $cmdcomment= ($opencmd =~ m/^%/);  # Flag to indicate whether opencmd is a comment (i.e. if we intend to simply comment out changed commands)
+  my ($command,$commandword,$closingbracket) ; # temporary variables needed below to remember sub-pattern matches
+
+# split this block to flatten out sequences joined in pass1
+  @$block=splitlatex(join "",@$block);
+  foreach (@$block) {
+    $word=$_; 
+    if ( $word =~ s/^%/%$comment/ ) {
+      # a comment
+      if ($cmd==1) {
+	push (@$retval,$closecmd) ;
+	$cmd=-1;
+      }
+      push (@$retval,$word); 
+      next;
+    }
+    if (! $noncomment) {
+      push (@$retval,$openmark); 
+      $noncomment=1;
+    }
+    # negative lookahead pattern (?!) in second clause is put in to avoid mathcing \( .. \) patterns
+    if ( $word =~ /^[&{}\[\]]/ || ( $word =~ /^\\(?!\()([\w*@]*)/ && !iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL)) ) {
+      # word is a command or other significant token (not in SAFECMDLIST)
+	## same conditions as in subroutine extractcommand:
+	# check if token is an alphanumeric command sequence with at least one non-optional argument
+	# \cmd[...]{...}{last argument}  
+	# Capturing in the following results in these associations
+	# $1: \cmd[...]{...}{
+	# $2: \cmd
+	# $3: last argument
+	# $4: }  + trailing spaces
+	### pre-0.3    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:\[$brat0\]|\{$pat4\})*\{)($pat4)(\}\s*)$/so )
+      if ( ( $word =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	   && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL)  && ( !$cmdcomment || !iscmd($2,\@CONTEXT2CMDLIST, \@CONTEXT2CMDEXCL) )  ) {	 
+	# word is a text command - we mark up the interior of the word. But if we are in a deleted block ($cmdcomment=1) and
+        # $2 (the command) is in context2, just treat it as an ordinary command (i.e. comment it open with $opencmd)
+        # Because we do not want to disable this command
+	# here we do not use $opencmd and $closecmd($opencmd is empty) 
+	if ($cmd==1) {
+	  push (@$retval,$closecmd) ;
+	} elsif ($cmd==0) { 
+	  push (@$retval,$close) ;
+	}
+        $command=$1; $commandword=$2; $closingbracket=$4;
+	@argtext=splitlatex($3);   # split textual argument into tokens
+	# and mark it up (but we do not need openmark and closemark)
+        # insert command with initial arguments, marked-up final argument, and closing bracket
+	if ( $cmdcomment && iscmd($commandword,\@CONTEXT1CMDLIST, \@CONTEXT1CMDEXCL) ) {
+	  # context1cmd in a deleted environment; delete command itself but keep last argument, marked up
+	  push (@$retval,$opencmd);
+	  $command =~ s/\n/\n${opencmd}/sg ; # repeat opencmd at the beginning of each line
+	  # argument, note that the additional comment character is included
+          # to suppress linebreak after opening parentheses, which is important
+          # for latexrevise
+          push (@$retval,$command,"%\n{$AUXCMD\n",marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);
+	} else {
+	  # normal textcmd or context1cmd in an added block
+	  push (@$retval,$command,marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);  
+	}
+	push (@$retval,$AUXCMD,"\n") if $cmdcomment ;
+	$cmd=-1 ;
+      } else {
+	# ordinary command
+	push (@$retval,$opencmd) if $cmd==-1 ;
+	push (@$retval,$close,$opencmd) if $cmd==0 ;
+	$word =~ s/\n/\n${opencmd}/sg if $cmdcomment ;   # if opencmd is a comment, repeat this at the beginning of every line
+	push (@$retval,$word);
+	$cmd=1;
+      }
+    } else {
+      # just an ordinary word or word in SAFECMD
+      push (@$retval,$open) if $cmd==-1 ;
+      push (@$retval,$closecmd,$open) if $cmd==1 ;
+      push (@$retval,$word);
+      $cmd=0;
+    }
+  }
+  push (@$retval,$close) if $cmd==0;
+  push (@$retval,$closecmd) if $cmd==1;
+
+  push (@$retval,$closemark) if ($noncomment);
+  return @$retval;
+}
+
+# preprocess($string, ..)
+# carry out the following pre-processing steps for all arguments:
+# 1. Remove leading white-space
+# 2. mark all first empty line (in block of several) with \PAR tokens
+# 3. Convert all '\%' into '\PERCENTAGE ' to make parsing regular expressions easier
+# 4. Convert all \verb|some verbatim text| commands (where | can be an arbitrary character)
+#    into \verb{hash}
+# 5. Convert \begin{verbatim} some verbatim text \end{verbatim} into \verbatim{hash}
+# 6. Convert _n into \SUBSCRIPTNB{n} and _{nnn} into \SUBSCRIPT{nn}
+# 7. Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+# 8. a. Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+#    b. Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+
+# 9. Add final token STOP to the very end.  This is put in because the algorithm works better if the last token is identical.  This is removed again in postprocessing.
+#
+# NB: step 6 and 7 is likely to  convert some "_" inappropriately, e.g. in file
+#     names or labels but it does not matter because they are converted back in the postprocessing step
+# Returns: leading white space removed in step 1
+sub preprocess {
+  my @leadin=() ;
+  for (@_) { 
+    s/^(\s*)//s;
+    push(@leadin,$1);
+    s/\n(\s*?)\n((?:\s*\n)*)/\n$1\\PAR\n$2/g ;
+    s/(?<!\\)\\%/\\PERCENTAGE /g ;  # (?<! is negative lookbehind assertion to prevent \\% from being converted
+    s/(\\verb\*?)(\S)(.*?)\2/"${1}{". tohash(\%verbhash,"${2}${3}${2}") ."}"/esg;
+    s/\\begin\{(verbatim\*?)\}(.*?)\\end\{\1\}/"\\${1}{". tohash(\%verbhash,"${2}") . "}"/esg;
+    # Convert _n or _\cmd into \SUBSCRIPTNB{n} or \SUBSCRIPTNB{\cmd} and _{nnn} into \SUBSCRIPT{nn}
+    s/_([^{\\]|\\\w+)/\\SUBSCRIPTNB{$1}/g ;
+    s/_{($pat4)}/\\SUBSCRIPT{$1}/g ;
+    # Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+    s/\^([^{\\]|\\\w+)/\\SUPERSCRIPTNB{$1}/g ;
+    s/\^{($pat4)}/\\SUPERSCRIPT{$1}/g ;
+    # Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+    s/\$\$(.*?)\$\$/\\begin{DOLLARDOLLAR}$1\\end{DOLLARDOLLAR}/sg;
+    # Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+    s/(?<!\\)\\\[/\\begin{SQUAREBRACKET}/sg;
+    s/\\\]/\\end{SQUAREBRACKET}/sg;
+    # add final token " STOP"
+    $_ .= " STOP"
+  }
+  return(@leadin);
+}
+
+#hashstring=tohash(\%hash,$string)
+# creates a hash value based on string and stores in %hash
+sub tohash {
+  my ($hash,$string)=@_;
+  my (@arr,$val);
+  my ($sum,$i)=(0,1);
+  my ($hstr);
+
+  @arr=unpack('c*',$string);
+
+  foreach $val (@arr) {
+    $sum += $i*$val;
+    $i++;
+  }
+  $hstr= "$sum";
+  if (defined($hash->{$hstr}) && $string ne $hash->{$hstr}) {
+    warn "Repeated hash value for verbatim mode in spite of different content.";
+    $hstr="-$hstr";
+  }
+  $hash->{$hstr}=$string;
+  return($hstr);
+}
+
+#string=fromhash(\%hash,$fromstring)
+# restores string value stored in hash
+#string=fromhash(\%hash,$fromstring,$prependstring)
+# additionally begins each line with prependstring
+sub fromhash {
+  my ($hash,$hstr)=($_[0],$_[1]);
+  my $retstr=$hash->{$hstr};
+  if ( $#_ >= 2) {
+    $retstr =~ s/^/$_[2]/mg;
+  }
+  return $retstr;
+}
+
+
+# postprocess($string, ..)
+# carry out the following post-processing steps for all arguments:
+# * Remove STOP token from the end
+# * Replace \RIGHTBRACE by }
+# 1. Check all deleted blocks: 
+#    a.where a deleted block contains a matching \begin and
+#      \end environment (these will be disabled by a %DIFDELCMD statements), for selected environment enable enable
+#      these commands again (such that for example displayed math in a deleted equation
+#      is properly within math mode.  For math mode environments replace numbered equation
+#      environments with their display only variety (so that equation numbers in new file and
+#      diff file are identical).  Where the correct type of math environment cannot be determined
+#      use a place holder MATHMODE
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+#    Replace all MATHMODE environment commands by the correct environment to achieve matching
+#    pairs
+#    c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+# 2. Remove DIFadd, DIFdel, DIFFaddbegin , ... from picture environments
+# 3. Convert DIFadd, DIFdel, DIFFaddbegin , ... into FL varieties
+#    within floats (currently recognised float environments: plate,table,figure
+#    plus starred varieties).
+# 4. Remove empty %DIFDELCMD < lines 
+# 4. Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+#    Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+# 6. Convert  \SUBSCRIPTNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+# 7. Expand hashes of verb and verbatim environments
+# 8. Convert '\PERCENTAGE ' back into '\%'
+# 9.. remove all \PAR tokens
+# 10.  package specific processing:  endfloat: make sure \begin{figure} and \end{figure} are always
+#      on a line by themselves, similarly for table environment
+#  4, undo renaming of the \begin and \end in comments
+
+#
+# Note have to manually synchronize substitution commands below and 
+# DIF.. command names in the header
+sub postprocess {
+  my ($begin,$len,$cnt,$float,$delblock,$addblock);
+  # second level blocks
+  my ($begin2,$cnt2,$len2,$eqarrayblock,$mathblock);
+
+  for (@_) { 
+
+    # change $'s in comments to something harmless
+    1 while s/(%.*)\$/$1DOLLARDIF/mg ;
+
+    # Remove final STOP token
+    s/ STOP$//;
+    # Replace \RIGHTBRACE by }    
+    s/\\RIGHTBRACE/}/g;
+    # Check all deleted blocks: where a deleted block contains a matching \begin and
+    #    \end environment (these will be disabled by a %DIFDELCMD statements), enable
+    #    these commands again (such that for example displayed math in a deleted equation
+    #    is properly within math mode.  For math mode environments replace numbered equation
+    #    environments with their display only variety (so that equation numbers in new file and
+    #    diff file are identical
+    while ( m/\\DIFdelbegin.*?\\DIFdelend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $delblock=$&;
+
+
+      ### (.*?[^\n]?)\n? construct is necessary to avoid empty lines in math mode, which result in
+      ### an error
+      # displayed math environments
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHREPL}$AUXCMD\n$1$3\n\\end{$MATHREPL}$AUXCMD\n$4/sg;
+      # also transform the opposite pair \end{displaymath} .. \begin{displaymath} but we have to be careful not to interfere with the results of the transformation in the line directly above
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHENV}; if found add \begin{$MATHREPL} and insert \end{$MATHREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+
+      # equation array environment
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHARRREPL}$AUXCMD\n$1$3\n\\end{$MATHARRREPL}$AUXCMD\n$4/sg;
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHARRENV}; if found add \begin{$MATHARRREPL} and insert \end{$MATHARRREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHARRREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHARRREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+      # parse $delblock for deleted and reinstated eqnarray* environments - within those reinstate \\ and & commands
+      while ( $delblock =~ m/\\begin\Q{$MATHARRREPL}$AUXCMD\E\n.*?\n\\end\Q{$MATHARRREPL}$AUXCMD\E\n/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$eqarrayblock=$&;
+	# reinstate deleted & and \\ commands
+	$eqarrayblock=~ s/(\%DIFDELCMD < \s*(\&|\\\\)\s*?(?:$DELCMDCLOSE|\n))/$1$2$AUXCMD\n/sg ;
+
+	substr($delblock,$begin2,$len2)=$eqarrayblock;
+	pos($delblock) = $begin2 + length($eqarrayblock);
+      }
+
+
+
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+      $delblock=~ s/\\($COUNTERCMD)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*\s*${AUXCMD}\n)/\\$1$2\\addtocounter{$1}{-1}${AUXCMD}\n/sg ;
+#     c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+      while ( $delblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($delblock,$begin2,$len2)=$mathblock;
+	pos($delblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified delblock
+      substr($_,$begin,$len)=$delblock;
+      pos = $begin + length($delblock);
+    }
+    # make the array modification in added blocks
+    while ( m/\\DIFaddbegin.*?\\DIFaddend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $addblock=$&;
+      while ( $addblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($addblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($addblock,$begin2,$len2)=$mathblock;
+	pos($addblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified addblock
+      substr($_,$begin,$len)=$addblock;
+      pos = $begin + length($addblock);
+    }
+
+
+    ### old place for BEGINDIF, ENDDIF replacement
+    # change begin and end commands  within comments such that they
+    # don't disturb the pattern matching (if there are several \begin or \end in one line
+    # this substitution is insufficient but that appears unlikely)
+    s/(%.*)\\begin\{(.*)$/$1\\BEGINDIF\{$2/mg ;
+    s/(%.*)\\end\{(.*)$/$1\\ENDDIF\{$2/mg ;
+
+    # Replace MATHMODE environments from step 1a above by the correct Math environment
+
+    # The next line is complicated.  The negative look-ahead insertion makes sure that no \end{$MATHENV} (or other mathematical
+    # environments) are between the \begin{$MATHENV} and \end{MATHMODE} commands. This is necessary as the minimal matching 
+    # is not globally minimal but only 'locally' (matching is beginning from the left side of the string)
+    1 while s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}((?:.(?!(?:\\end{(?:(?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}|\\begin{MATHMODE})))*?)\\end{MATHMODE}/\\begin{$1}$2\\end{$1}/s;
+    1 while s/\\begin{MATHMODE}((?:.(?!\\end{MATHMODE}))*?)\\end{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}/\\begin{$2}$1\\end{$2}/s;
+    # convert remaining \begin{MATHMODE} \end{MATHMODE} (and not containing & or \\ )into MATHREPL environments
+    s/\\begin{MATHMODE}((?:(.(?!(?<!\\)\&|\\\\))*)?)\\end{MATHMODE}/\\begin{$MATHREPL}$1\\end{$MATHREPL}/sg;
+    # others into MATHARRREPL
+    s/\\begin{MATHMODE}(.*?)\\end{MATHMODE}/\\begin{$MATHARRREPL}$1\\end{$MATHARRREPL}/sg;
+
+    # now look for AUXCMD math-mode pairs which have only comments (or empty lines between them), and remove the added commands
+    s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}$AUXCMD\n((?:\s*%.[^\n]*\n)*)\\end{\1}$AUXCMD\n/$2/sg; 
+
+
+    # Remove all mark up within picture environments
+    while ( m/\\begin\{($PICTUREENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin //g;
+      $float =~ s/\\DIFaddend //g;
+      $float =~ s/\\DIFadd\{($pat4)\}/$1/g;
+      $float =~ s/\\DIFdelbegin //g;
+      $float =~ s/\\DIFdelend //g;
+      $float =~ s/\\DIFdel\{($pat4)\}//g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    # Convert DIFadd, DIFdel, DIFFaddbegin , ... into  varieties
+    #    within floats (currently recognised float environments: plate,table,figure
+    #    plus starred varieties).
+    while ( m/\\begin\{($FLOATENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin /\\DIFaddbeginFL /g;
+      $float =~ s/\\DIFaddend /\\DIFaddendFL /g;
+      $float =~ s/\\DIFadd\{/\\DIFaddFL{/g;
+      $float =~ s/\\DIFdelbegin /\\DIFdelbeginFL /g;
+      $float =~ s/\\DIFdelend /\\DIFdelendFL /g;
+      $float =~ s/\\DIFdel\{/\\DIFdelFL{/g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    ### former location of undo renaming of \begin and \end in comments
+
+    # remove empty DIFCMD < lines
+    s/^\Q${DELCMDOPEN}\E\n//msg;
+
+    # Expand hashes of verb and verbatim environments (note negative look behind assertion to not leak out of DIFDELCMD comments
+    s/(\\verb\*?)\{([-\d]*?)\}/"${1}". fromhash(\%verbhash,$2)/esg;
+    s/${DELCMDOPEN}\\(verbatim\*?)\{([-\d]*?)\}/"${DELCMDOPEN}\\begin{${1}}".fromhash(\%verbhash,$2,$DELCMDOPEN)."${DELCMDOPEN}\\end{${1}}"/esg;
+    s/\\(verbatim\*?)\{([-\d]*?)\}/"\\begin{${1}}".fromhash(\%verbhash,$2)."\\end{${1}}"/esg;
+    # Convert '\PERCENTAGE ' back into '\%'			       
+    s/\\PERCENTAGE /\\%/g;
+    # remove all \PAR tokens (taking care to properly keep commented out PAR's
+    # from introducing uncommented newlines - next line)
+    s/(%DIF < )([^\n]*?)\\PAR\n/$1$2\n$1\n/sg;
+    # convert PAR commands which are on a line by themselves
+    s/\n(\s*?)\\PAR\n/\n\n/sg;
+    # convert remaining PAR commands (which are preceded by non-white space characters, usually "}" ($ADDCLOSE)
+    s/\\PAR\n/\n\n/sg;
+
+    #  package specific processing: 
+    if ( defined($packages{"endfloat"})) {
+      #endfloat: make sure \begin{figure} and \end{figure} are always
+      #      on a line by themselves, similarly for table environment
+      print STDERR "endfloat package detected.\n" if $verbose ;
+      # eliminate whitespace before and after
+      s/^(\s*)(\\(?:begin|end)\{(?:figure|table)\})(\s*)$/$2/mg;
+      # split lines with remaining characters before float enviroment conmmand
+      s/^(.+)(\\(?:begin|end)\{(?:figure|table)\})/$1\n$2/mg;
+      # split lines with remaining characters after float enviroment conmmand
+      s/(\\(?:begin|end)\{(?:figure|table)\})(.+)$/$1\n$2/mg;
+    }
+    # undo renaming of the \begin and \end  and dollars in comments 
+    s/(%.*)\\BEGINDIF\{(.*)$/$1\\begin\{$2/mg ;
+    s/(%.*)\\ENDDIF\{(.*)$/$1\\end\{$2/mg ;
+    1 while s/(%.*)DOLLARDIF/$1\$/mg ;
+#   Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+    s/\\end{SQUAREBRACKET}/\\\]/sg;
+    s/\\begin{SQUAREBRACKET}/\\\[/sg;
+# 4. Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+    s/\\begin\{DOLLARDOLLAR\}(.*?)\\end\{DOLLARDOLLAR\}/\$\$$1\$\$/sg;
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+    s/\\SUPERSCRIPTNB{($pat0)}/^$1/g ;
+    s/\\SUPERSCRIPT{($pat4)}/^{$1}/g ;
+    # Convert  \SUBSCRIPNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+    s/\\SUBSCRIPTNB{($pat0)}/_$1/g ;
+    s/\\SUBSCRIPT{($pat4)}/_{$1}/g ;
+
+  return;
+  }
+}
+
+
+# @diffs=linediff(\@seq1, \@seq2)
+# mark up lines like this
+#%DIF mm-mmdnn
+#%< old deleted line(s)
+#%DIF -------
+#%DIF mmann-nn
+#new appended line %< 
+#%DIF -------
+# Future extension: mark change explicitly
+# Assumes: traverse_sequence traverses deletions before insertions in changed sequences
+#          all line numbers relative to line 0 (first line of real file)
+sub linediff {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $block = [];
+  my $retseq = [];
+  my @begin=('','',''); # dummy initialisation
+  my $instring ; 
+
+  my $discard = sub { @begin=('d',$_[0],$_[1]) unless scalar @$block ; 
+                      push(@$block, "%DIF < " . $seq1->[$_[0]]) };
+  my $add = sub { if (! scalar  @$block) {
+		    @begin=('a',$_[0],$_[1]) ;}
+		  elsif ( $begin[0] eq 'd' ) {
+                    $begin[0]='c'; $begin[2]=$_[1];
+		    push(@$block, "%DIF -------") }
+                  push(@$block,  $seq2->[$_[1]] . " %DIF > " ) };
+  my $match = sub { if ( scalar @$block ) {
+                      if ( $begin[0] eq 'd' && $begin[1]!=$_[0]-1) {
+			$instring = sprintf "%%DIF %d-%dd%d",$begin[1],$_[0]-1,$begin[2]; }
+		      elsif ( $begin[0] eq 'a' && $begin[2]!=$_[1]-1) {
+			$instring = sprintf "%%DIF %da%d-%d",$begin[1],$begin[2],$_[1]-1; }
+		      elsif ( $begin[0] eq 'c' ) {
+			$instring = sprintf "%%DIF %sc%s",
+			                     ($begin[1]==$_[0]-1) ? "$begin[1]" : $begin[1]."-".($_[0]-1)  , 
+			                     ($begin[2]==$_[1]-1) ? "$begin[2]" : $begin[2]."-".($_[1]-1)  ; }
+		      else {
+			$instring = sprintf "%%DIF %d%s%d",$begin[1],$begin[0],$begin[2]; }
+		      push @$retseq, $instring,@$block, "%DIF -------" ; 
+		      $block = []; 
+		    }
+		    push @$retseq, $seq2->[$_[1]]
+		  };
+  # key function: remove multiple spaces (such that insertion or deletion of redundant white space is not reported)
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  push @$retseq, @$block if scalar @$block; 
+
+  return wantarray ? @$retseq : $retseq ;
+}
+
+
+
+# init_regex_arr_data(\@array,"TOKEN INIT")
+# scans DATA file handel for line "%% TOKEN INIT" line
+# then appends each line not beginning with % into array (as a quoted regex)
+sub init_regex_arr_data {
+  my ($arr,$token)=@_;
+  my ($copy);
+  while (<DATA>) {
+    if ( m/^%%BEGIN $token\s*$/ ) {
+      $copy=1; }
+    elsif ( m/^%%END $token\s*/ )  {
+      last; }
+    chomp;
+    push (@$arr,qr/^$_$/) if ( $copy && !/^%/ ) ;
+  }
+  seek DATA,0,0;    # rewind DATA handle to file begin
+}
+
+
+# init_regex_arr_ext(\@array,$arg)
+# fills array with regular expressions.
+# if arg is a file name, then read in list of regular expressions from that file
+# (one expression per line)
+# Otherwise treat arg as a comma separated list of regular expressions
+sub init_regex_arr_ext {
+  my ($arr,$arg)=@_;
+  my $regex;
+  if ( -f $ arg ) {
+    open(FILE,"$arg") or die ("Couldn't open $arg: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@$arr,qr/^$_$/);
+    }
+    close(FILE);
+  }
+  else {
+    # assume it is a comma-separated list of reg-ex
+    foreach $regex (split(qr/(?<!\\),/,$arg)) {
+      $regex =~ s/\\,/,/g;
+      push (@$arr,qr/^$regex$/);
+    }
+  }
+}
+
+#exetime() returns time since last execution of this command
+#exetime(1) resets this time
+my $lasttime=-1;   # global variable for persistence
+sub exetime {
+  my $reset=0;
+  my $retval;
+  if ((scalar @_) >=1) {
+    $reset=shift;
+  }
+  if ($reset) {
+    $lasttime=times();
+  }
+  else {
+    $retval=times()-$lasttime;
+    $lasttime=$lasttime+$retval;
+    return($retval);
+  }
+}
+
+
+sub usage {
+  die <<"EOF"; 
+Usage: $0 [options] old.tex new.tex > diff.tex
+
+Compares two latex files and writes tex code to stdout, which has the same
+format as new.tex but has all changes relative to old.tex marked up or commented.
+
+--type=markupstyle
+-t markupstyle         Add code to preamble for selected markup style
+                       Available styles: UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+                                         CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR
+                       [ Default: UNDERLINE ]
+
+--subtype=markstyle
+-s markstyle           Add code to preamble for selected style for bracketing
+                       commands (e.g. to mark changes in  margin)
+                       Available styles: SAFE MARGINAL DVIPSCOL
+                       [ Default: SAFE ]
+
+--floattype=markstyle
+-f markstyle           Add code to preamble for selected style which 
+                       replace standard marking and markup commands within floats
+                       (e.g., marginal remarks cause an error within floats
+                       so marginal marking can be disabled thus)
+                       Available styles: FLOATSAFE IDENTICAL
+                       [ Default: FLOATSAFE ]
+
+--encoding=enc
+-e enc                 Specify encoding of old.tex and new.tex. Typical encodings are
+                       ascii, utf8, latin1, latin9.  A list of available encodings can be 
+                       obtained by executing 
+                       perl -MEncode -e 'print join ("\\n",Encode->encodings( ":all" )) ;'
+                       [Default encoding is utf8 unless the first few lines of the preamble contain
+                       an invocation "\\usepackage[..]{inputenc} in which case the 
+                       encoding chosen by this command is asssumed. Note that ASCII (standard
+                       latex) is a subset of utf8]
+
+--preamble=file
+-p file                Insert file at end of preamble instead of auto-generating
+                       preamble.  The preamble must define the following commands
+                       \\DIFaddbegin,\\DIFaddend,\\DIFadd{..},
+                       \\DIFdelbegin,\\DIFdelend,\\DIFdel{..},
+                       and varieties for use within floats
+                       \\DIFaddbeginFL,\\DIFaddendFL,\\DIFaddFL{..},
+                       \\DIFdelbeginFL,\\DIFdelendFL,\\DIFdelFL{..}
+                       (If this option is set -t, -s, and -f options
+                       are ignored.)
+
+--exclude-safecmd=exclude-file
+--exclude-safecmd="cmd1,cmd2,..."
+-A exclude-file 
+--replace-safecmd=replace-file
+--append-safecmd=append-file
+--append-safecmd="cmd1,cmd2,..."
+-a append-file         Exclude from, replace or append to the list of regex
+                       matching commands which are safe to use within the 
+                       scope of a \\DIFadd or \\DIFdel command.  The file must contain
+                       one Perl-RegEx per line (Comment lines beginning with # or % are
+                       ignored). A literal comma within the comma-separated list must be
+                       escaped thus "\\,",   Note that the RegEx needs to match the whole of 
+                       the token, i.e., /^regex\$/ is implied and that the initial
+                       "\\" of the command is not included. The --exclude-safecmd
+                       and --append-safecmd options can be combined with the --replace-safecmd 
+                       option and can be used repeatedly to add cumulatively to the lists.
+
+--exclude-textcmd=exclude-file 
+--exclude-textcmd="cmd1,cmd2,..."
+-X exclude-file
+--replace-textcmd=replace-file
+--append-textcmd=append-file
+--append-textcmd="cmd1,cmd2,..."
+-x append-file         Exclude from, replace or append to the list of regex
+                       matching commands whose last argument is text.  See
+                       entry for --exclude-safecmd directly above for further details.
+
+--replace-context1cmd=replace-file
+--append-context1cmd=append-file
+--append-context1cmd="cmd1,cmd2,..."
+                       Replace or append to the list of regex matching commands
+                       whose last argument is text but which require a particular
+                       context to work, e.g. \\caption will only work within a figure
+                       or table.  These commands behave like text commands, except when 
+                       they occur in a deleted section, when they are disabled, but their
+                       argument is shown as deleted text.
+
+--replace-context2cmd=replace-file
+--append-context2cmd=append-file
+--append-context2cmd="cmd1,cmd2,..."
+                       As corresponding commands for context1.  The only difference is that
+                       context2 commands are completely disabled in deleted sections, including
+                       their arguments.
+
+
+--config var1=val1,var2=val2,...
+-c var1=val1,..        Set configuration variables.
+-c configfile           Available variables: 
+                          MINWORDSBLOCK (integer)
+                          FLOATENV (RegEx)
+                          PICTUREENV (RegEx)
+                          MATHENV (RegEx)
+                          MATHREPL (String)
+                          MATHARRENV (RegEx)
+                          MATHARRREPL (String)
+                          ARRENV (RegEx)
+                          COUNTERCMD (RegEx)
+                       This option can be repeated.
+
+
+--packages=pkg1,pkg2,..
+                       Tell latexdiff that .tex file is processed with the packages in list 
+                       loaded.  This is normally not necessary if the .tex file includes the
+                       preamble, as the preamble is automatically scanned for \\usepackage commands.
+                       Use of the --packages option disables automatic scanning, so if for any
+                       reason package specific parsing needs to be switched off, use --packages=none.
+                       The following packages trigger special behaviour:
+                       endfloat hyperref amsmath
+                       [ Default: scan the preamble for \\usepackage commands to determine
+                         loaded packages.]
+
+--show-preamble        Print generated or included preamble commands to stdout.
+
+--show-safecmd         Print list of regex matching and excluding safe commands.
+
+--show-textcmd         Print list of regex matching and excluding commands with text argument.
+
+--show-config          Show values of configuration variables
+
+--show-all             Show all of the above
+
+   NB For all --show commands, no old.tex or new.tex file needs to be given, and no 
+      differencing takes place.
+
+--allow-spaces         Allow spaces between bracketed or braced arguments to commands
+                       [Default requires arguments to directly follow each other without 
+                                intervening spaces]
+
+--flatten              Replace \\input and \\include commands within body by the content
+                       of the files in their argument.  If \\includeonly is present in the
+                       preamble, only those files are expanded into the document. However, 
+                       no recursion is done, i.e. \\input and \\include commands within 
+                       included sections are not expanded.  The included files are assumed to 
+                       be located in the same directories as the old and new master files,
+                       respectively, making it possible to organise files into old and new directories.
+
+--help
+-h                     Show this help text.
+
+--ignore-warnings      Suppress warnings about inconsistencies in length between input
+                       and parsed strings and missing characters. 
+
+--verbose
+-V                     Output various status information to stderr during processing.
+                       Default is to work silently.
+
+--version              Show version number.
+EOF
+}
+
+=head1 NAME
+
+latexdiff - determine and markup differences between two latex files
+
+=head1 SYNOPSIS
+
+B<latexdiff> [ B<OPTIONS> ] F<old.tex> F<new.tex> > F<diff.tex>
+
+=head1 DESCRIPTION
+
+Briefly, I<latexdiff> is a utility program to aid in the management of
+revisions of latex documents. It compares two valid latex files, here
+called C<old.tex> and C<new.tex>, finds significant differences
+between them (i.e., ignoring the number of white spaces and position
+of line breaks), and adds special commands to highlight the
+differences.  Where visual highlighting is not possible, e.g. for changes
+in the formatting, the differences are
+nevertheless marked up in the source.
+
+The program treats the preamble differently from the main document.
+Differences between the preambles are found using line-based
+differencing (similarly to the Unix diff command, but ignoring white
+spaces).  A comment, "S<C<%DIF E<gt>>>" is appended to each added line, i.e. a 
+line present in C<new.tex> but not in C<old.tex>.  Discarded lines 
+ are deactivated by prepending "S<C<%DIF E<lt>>>". Changed blocks are preceded  by
+comment lines giving information about line numbers in the original files.  Where there are insignificant
+differences, the resulting file C<diff.tex> will be similar to
+C<new.tex>.  At the end of the preamble, the definitions for I<latexdiff> markup commands are inserted.
+In differencing the main body of the text, I<latexdiff> attempts to
+satisfy the following guidelines (in order of priority):
+
+=over 3
+
+=item 1
+
+If both C<old.tex> and C<new.tex> are valid LaTeX, then the resulting
+C<diff.tex> should also be valid LateX. (NB If a few plain TeX commands
+are used within C<old.tex> or C<new.tex> then C<diff.tex> is not
+guaranteed to work but usually will).
+
+=item 2
+
+Significant differences are determined on the level of
+individual words. All significant differences, including differences
+between comments should be clearly marked in the resulting source code
+C<diff.tex>.
+
+=item 3
+
+If a changed passage contains text or text-producing commands, then
+running C<diff.tex> through LateX should produce output where added
+and discarded passages are highlighted.
+
+=item 4
+
+Where there are insignificant differences, e.g. in the positioning of
+line breaks, C<diff.tex> should follow the formatting of C<new.tex>
+
+=back
+
+For differencing the same algorithm as I<diff> is used but words
+instead of lines are compared.  An attempt is made to recognize
+blocks which are completely changed such that they can be marked up as a unit.
+Comments are differenced line by line
+but the number of spaces within comments is ignored. Commands including
+all their arguments are generally compared as one unit, i.e., no mark-up
+is inserted into the arguments of commands.  However, for a selected
+number of commands (for example, C<\caption> and all sectioning
+commands) the last argument is known to be text. This text is
+split into words and differenced just as ordinary text (use options to
+show and change the list of text commands, see below). As the
+algorithm has no detailed knowledge of LaTeX, it assumes all pairs of
+curly braces immediately following a command (i.e. a sequence of
+letters beginning with a backslash) are arguments for that command.
+As a restriction to condition 1 above it is thus necessary to surround
+all arguments with curly braces, and to not insert
+extraneous spaces.  For example, write 
+
+  \section{\textem{This is an emphasized section title}}
+
+and not
+
+  \section {\textem{This is an emphasized section title}}
+
+or
+
+  \section\textem{This is an emphasized section title}
+
+even though all varieties are the same to LaTeX (but see
+B<--allow-spaces> option which allows the second variety).
+
+For environments whose content does not conform to standard LaTeX or
+where graphical markup does not make sense all markup commands can be
+removed by setting the PICTUREENV configuration variable, set by
+default to C<picture> and C<DIFnomarkup> environments; see B<--config>
+option).  The latter environment (C<DIFnomarkup>) can be used to
+protect parts of the latex file where the markup results in illegal
+markup. You have to surround the offending passage in both the old and
+new file by C<\begin{DIFnomarkup}> and C<\end{DIFnomarkup}>. You must
+define the environment in the preambles of both old and new
+documents. I prefer to define it as a null-environment,
+
+C<\newenvironment{DIFnomarkup}{}{}>
+
+but the choice is yours.  Any markup within the environment will be
+removed, and generally everything within the environment will just be
+taken from the new file.
+
+It is also possible to difference files which do not have a preamble. 
+ In this case, the file is processed in the main document
+mode, but the definitions of the markup commands are not inserted.
+
+All markup commands inserted by I<latexdiff> begin with "C<\DIF>".  Added
+blocks containing words, commands or comments which are in C<new.tex>
+but not in C<old.tex> are marked by C<\DIFaddbegin> and C<\DIFaddend>.
+Discarded blocks are marked by C<\DIFdelbegin> and C<\DIFdelend>.
+Within added blocks all text is highlighted with C<\DIFadd> like this:
+C<\DIFadd{Added text block}>
+Selected `safe' commands can be contained in these text blocks as well
+(use options to show and change the list of safe commands, see below).
+All other commands as well as braces "{" and "}" are never put within
+the scope of C<\DIFadd>.  Added comments are marked by prepending
+"S<C<%DIF E<gt> >>".
+
+Within deleted blocks text is highlighted with C<\DIFdel>.  Deleted
+comments are marked by prepending "S<C<%DIF E<lt> >>".  Non-safe command
+and curly braces within deleted blocks are commented out with 
+"S<C<%DIFDELCMD E<lt> >>".
+
+
+
+=head1 OPTIONS
+
+=head2 Preamble
+
+The following options determine the visual markup style by adding the appropriate
+command definitions to the preamble. See the end of this section for a description of 
+available styles.
+
+=over 4
+
+=item B<--type=markupstyle> or
+B<-t markupstyle>
+
+Add code to preamble for selected markup style. This option defines
+C<\DIFadd> and C<\DIFdel> commands.
+Available styles: 
+
+C<UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR>
+
+[ Default: C<UNDERLINE> ]
+
+=item B<--subtype=markstyle> or
+B<-s markstyle> 
+
+Add code to preamble for selected style for bracketing
+commands (e.g. to mark changes in  margin). This option defines
+C<\DIFaddbegin>, C<\DIFaddend>, C<\DIFdelbegin> and C<\DIFdelend> commands.
+Available styles: C<SAFE MARGINAL DVIPSCOL>
+
+[ Default: C<SAFE> ]
+
+=item B<--floattype=markstyle> or
+B<-f markstyle>
+
+Add code to preamble for selected style which 
+replace standard marking and markup commands within floats
+(e.g., marginal remarks cause an error within floats
+so marginal marking can be disabled thus). This option defines all 
+C<\DIF...FL> commands.
+Available styles: C<FLOATSAFE TRADITIONALSAFE IDENTICAL>
+
+[ Default: C<FLOATSAFE> ]
+
+=item B<--encoding=enc> or 
+B<-e enc>
+
+Specify encoding of old.tex and new.tex. Typical encodings are
+C<ascii>, C<utf8>, C<latin1>, C<latin9>.  A list of available encodings can be 
+obtained by executing 
+
+C<perl -MEncode -e 'print join ("\n",Encode->encodings( ":all" )) ;' >
+
+[Default encoding is utf8 unless the first few lines of the preamble contain
+an invocation C<\usepackage[..]{inputenc}> in which case the 
+encoding chosen by this command is asssumed. Note that ASCII (standard
+latex) is a subset of utf8]
+
+=item B<--preamble=file> or
+B<-p file>
+
+Insert file at end of preamble instead of generating
+preamble.  The preamble must define the following commands
+C<\DIFaddbegin, \DIFaddend, \DIFadd{..},
+\DIFdelbegin,\DIFdelend,\DIFdel{..},>
+and varieties for use within floats
+C<\DIFaddbeginFL, \DIFaddendFL, \DIFaddFL{..},
+\DIFdelbeginFL, \DIFdelendFL, \DIFdelFL{..}>
+(If this option is set B<-t>, B<-s>, and B<-f> options
+are ignored.)
+
+=item B<--packages=pkg1,pkg2,..> 
+
+Tell latexdiff that .tex file is processed with the packages in list
+loaded.  This is normally not necessary if the .tex file includes the
+preamble, as the preamble is automatically scanned for C<\usepackage> commands.
+Use of the B<--packages> option disables automatic scanning, so if for any
+reason package specific parsing needs to be switched off, use B<--packages=none>.
+The following packages trigger special behaviour:
+
+=over 8
+
+=item C<amsmath> 
+
+Configuration variable amsmath is set to C<align*> (Default: C<eqnarray*>)
+
+=item C<endfloat> 
+
+Ensure that C<\begin{figure}> and C<\end{figure}> always appear by themselves on a line.
+
+=item C<hyperref>
+
+Change name of C<\DIFadd> and C<\DIFdel> commands to C<\DIFaddtex> and C<\DIFdeltex> and 
+define new C<\DIFadd> and C<\DIFdel> commands, which provide a wrapper for these commands,
+using them for the text but not for the link defining command (where any markup would cause
+errors).
+
+=back
+
+[ Default: scan the preamble for C<\\usepackage> commands to determine
+  loaded packages.]
+
+
+
+=item B<--show-preamble>
+
+Print generated or included preamble commands to stdout.
+
+=back
+
+=head2 Configuration
+
+=over 4
+
+=item B<--exclude-safecmd=exclude-file> or
+B<-A exclude-file> or  B<--exclude-safecmd="cmd1,cmd2,...">
+
+=item B<--replace-safecmd=replace-file>
+
+=item B<--append-safecmd=append-file> or 
+B<-a append-file> or B<--append-safecmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions (RegEx)
+matching commands which are safe to use within the 
+scope of a C<\DIFadd> or C<\DIFdel> command.  The file must contain
+one Perl-RegEx per line (Comment lines beginning with # or % are
+ignored).  Note that the RegEx needs to match the whole of 
+the token, i.e., /^regex$/ is implied and that the initial
+"\" of the command is not included. 
+The B<--exclude-safecmd> and B<--append-safecmd> options can be combined with the -B<--replace-safecmd> 
+option and can be used repeatedly to add cumulatively to the lists.
+ B<--exclude-safecmd>
+and B<--append-safecmd> can also take a comma separated list as input. If a
+comma for one of the regex is required, escape it thus "\,". In most cases it
+will be necessary to protect the comma-separated list from the shell by putting
+it in quotation marks.
+
+=item B<--exclude-textcmd=exclude-file> or
+B<-X exclude-file> or B<--exclude-textcmd="cmd1,cmd2,...">
+
+=item B<--replace-textcmd=replace-file>
+
+=item B<--append-textcmd=append-file> or 
+B<-x append-file> or B<--append-textcmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions
+matching commands whose last argument is text.  See
+entry for B<--exclude-safecmd> directly above for further details.
+
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context1cmd=append-file> or
+=item B<--append-context1cmd="cmd1,cmd2,...">
+
+Replace or append to the list of regex matching commands
+whose last argument is text but which require a particular
+context to work, e.g. \caption will only work within a figure
+or table.  These commands behave like text commands, except when 
+they occur in a deleted section, when they are disabled, but their
+argument is shown as deleted text.
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context2cmd=append-file> or
+=item B<--append-context2cmd="cmd1,cmd2,...">
+As corresponding commands for context1.  The only difference is that
+context2 commands are completely disabled in deleted sections, including
+their arguments.
+
+
+
+=item B<--config var1=val1,var2=val2,...> or B<-c var1=val1,..>
+
+=item B<-c configfile>
+
+Set configuration variables.  The option can be repeated to set different
+variables (as an alternative to the comma-separated list).
+Available variables (see below for further explanations): 
+
+C<MINWORDSBLOCK> (integer)
+
+C<FLOATENV> (RegEx)
+
+C<PICTUREENV> (RegEx)
+
+C<MATHENV> (RegEx)
+
+C<MATHREPL> (String)
+
+C<MATHARRENV> (RegEx)
+
+C<MATHARRREPL> (String)
+
+C<ARRENV> (RegEx)
+
+C<COUNTERCMD> (RegEx)
+
+=item B<--show-safecmd>
+
+Print list of RegEx matching and excluding safe commands.
+
+=item B<--show-textcmd>
+
+Print list of RegEx matching and excluding commands with text argument.
+
+=item B<--show-config>
+
+Show values of configuration variables.
+
+=item B<--show-all>
+
+Combine all --show commands.
+
+NB For all --show commands, no C<old.tex> or C<new.tex> file needs to be specified, and no 
+differencing takes place.
+
+
+=back
+
+=head2 Miscellaneous
+
+=over 4
+
+=item B<--verbose> or B<-V>
+
+Output various status information to stderr during processing.
+Default is to work silently.
+
+=item B<--ignore-warnings>
+
+Suppress warnings about inconsistencies in length between input and
+parsed strings and missing characters.  These warning messages are
+often related to non-standard latex or latex constructions with a
+syntax unknown to C<latexdiff> but the resulting difference argument
+is often fully functional anyway, particularly if the non-standard
+latex only occurs in parts of the text which have not changed.
+
+=item B<--allow-spaces>
+
+Allow spaces between bracketed or braced arguments to commands.  Note
+that this option might have undesirable side effects (unrelated scope
+might get lumpeded with preceding commands) so should only be used if the
+default produces erroneous results.  (Default requires arguments to
+directly follow each other without intervening spaces).
+
+=item B<--flatten>
+
+Replace C<\input> and C<\include> commands within body by the content
+of the files in their argument.  If C<\includeonly> is present in the
+preamble, only those files are expanded into the document. However, 
+no recursion is done, i.e. C<\input> and C<\include> commands within 
+included sections are not expanded.  The included files are assumed to 
+ be located in the same directories as the old and new master files,
+respectively, making it possible to organise files into old and new directories. 
+
+Use of this option is not recommended
+primarily the processing time for the large documents is prohibitive, and
+the resulting difference document no longer reflects the structure of the 
+input documents. 
+
+=item B<--help> or
+B<-h>
+
+Show help text
+
+=item B<--version>
+
+Show version number
+
+=back
+
+=head2 Predefined styles 
+
+=head2 Major types
+
+The major type determine the markup of plain text and some selected latex commands outside floats by defining the markup commands C<\DIFadd{...}> and C<\DIFdel{...}> .
+
+=over 10
+
+=item C<UNDERLINE>
+
+Added text is wavy-underlined and blue, discarded text is struck out and red
+(Requires color and ulem packages).  Overstriking does not work in displayed math equations such that deleted parts of equation are underlined, not struck out (this is a shortcoming inherent to the ulem package).
+
+=item C<CTRADITIONAL>
+
+Added text is blue and set in sans-serif, and a red footnote is created for each discarded 
+piece of text. (Requires color package)
+
+=item C<TRADITIONAL>
+
+Like C<CTRADITIONAL> but without the use of color.
+
+=item C<CFONT>
+
+Added text is blue and set in sans-serif, and discarded text is red and very small size.
+
+=item C<FONTSTRIKE>
+
+Added tex is set in sans-serif, discarded text small and struck out
+
+=item C<CCHANGEBAR>
+
+Added text is blue, and discarded text is red.  Additionally, the changed text is marked with a bar in the margin (Requires color and changebar packages).
+
+=item C<CFONTCHBAR>
+
+Like C<CFONT> but with additional changebars (Requires color and changebar packages).
+
+=item C<CULINECHBAR>
+
+Like C<UNDERLINE> but with additional changebars (Requires color, ulem and changebar packages).
+
+=item C<CHANGEBAR>
+
+No mark up of text, but mark margins with changebars (Requires changebar package).
+
+=item C<INVISIBLE>
+
+No visible markup (but generic markup commands will still be inserted.
+
+=back
+
+=head2 Subtypes
+
+The subtype defines the commands that are inserted at the begin and end of added or discarded blocks, irrespectively of whether these blocks contain text or commands (Defined commands: C<\DIFaddbegin, \DIFaddend, \DIFdelbegin, \DIFdelend>) 
+
+=over 10
+
+=item C<SAFE>
+
+No additional markup (Recommended choice)
+
+=item C<MARGIN>
+
+Mark beginning and end of changed blocks with symbols in the margin nearby (using
+the standard C<\marginpar> command - note that this sometimes moves somewhat
+from the intended position.
+
+=item C<DVIPSCOL>
+
+An alternative way of marking added passages in blue, and deleted ones in red. Note
+that C<DVIPSCOL> only works with the dvips converter, e.g. not pdflatex.
+(it is recommeneded to use instead the main types to effect colored markup,
+although in some cases coloring with dvipscol can be more complete).
+
+=back
+
+=head2 Float Types
+
+Some of the markup used in the main text might cause problems when used within 
+floats (e.g. figures or tables).  For this reason alternative versions of all
+markup commands are used within floats. The float type defines these alternative commands.
+
+=over 10
+
+=item C<FLOATSAFE>
+
+Use identical markup for text as in the main body, but set all commands marking the begin and end of changed blocks to null-commands.  You have to choose this float type if your subtype is C<MARGIN> as C<\marginpar> does not work properly within floats.
+
+=item C<TRADITIONALSAFE>
+
+Mark additions the same way as in the main text.  Deleted environments are marked by angular brackets \[ and \] and the deleted text is set in scriptscript size. This float type should always be used with the C<TRADITIONAL> and  C<CTRADITIONAL> markup types as the \footnote command does not work properly in floating environments.
+
+=item C<IDENTICAL>
+
+Make no difference between the main text and floats.
+
+=back
+
+
+=head2 Configuration Variables
+
+=over 10
+
+=item C<MINWORDSBLOCK>
+
+Minimum number of tokens required to form an independent block. This value is
+used in the algorithm to detect changes of complete blocks by merging identical text parts of less than C<MINWORDSBLOCK> to the preceding added and discarded parts.
+
+[ Default: 3 ]
+
+=item C<FLOATENV>
+
+Environments whose name matches the regular expression in C<FLOATENV> are 
+considered floats.  Within these environments, the I<latexdiff> markup commands
+are replaced by their FL variaties.
+
+[ Default: S<C<(?:figure|table|plate)[\w\d*@]*> >]
+
+=item C<PICTUREENV>
+
+Within environments whose name matches the regular expression in C<PICTUREENV>
+all latexdiff markup is removed (in pathologic cases this might lead to
+ inconsistent markup but this situation should be rare).
+
+[ Default: S<C<(?:picture|DIFnomarkup)[\w\d*@]*> >]
+
+=item C<MATHENV>,C<MATHREPL>
+
+If both \begin and \end for a math environment (environment name matching C<MATHENV>
+or \[ and \])
+are within the same deleted block, they are replaced by a \begin and \end commands for C<MATHREPL>
+rather than being commented out.
+
+[ Default: C<MATHENV>=S<C<(?:displaymath|equation)> >, C<MATHREPL>=S<C<displaymath> >]
+
+=item C<MATHARRENV>,C<MATHARRREPL>
+
+as C<MATHENV>,C<MATHREPL> but for equation arrays
+
+[ Default: C<MATHARRENV>=S<C<eqnarray\*?> >, C<MATHREPL>=S<C<eqnarray> >]
+
+=item C<ARRENV>
+
+If a match to C<ARRENV> is found within an inline math environment within a deleted or added block, then the inlined math 
+is surrounded by C<\mbox{>...C<}>.  This is necessary as underlining does not work within inlined array environments.
+
+[ Default: C<ARRENV>=S<C<(?:array|[pbvBV]matrix)> >
+
+=item C<COUNTERCMD>
+
+If a command in a deleted block which is also in the textcmd list matches C<COUNTERCMD> then an
+additional command C<\addtocounter{>F<cntcmd>C<}{-1}>, where F<cntcmd> is the matching command, is appended in the diff file such that the numbering in the diff file remains synchronized with the
+numbering in the new file.
+
+[ Default: C<COUNTERCMD>=C<(?:footnote|part|section|subsection> ...
+
+C<|subsubsection|paragraph|subparagraph)>  ]
+
+=back
+
+=head1 BUGS
+
+UTF-8 support requires a relatively new version of perl (5.8.0 is sufficient 
+but 5.6.2 up would work OK, too).
+
+Option allow-spaces not implemented entirely consistently. It breaks
+the rules that number and type of white space does not matter, as
+different numbers of inter-argument spaces are treated as significant.
+
+Please send bug reports
+to I<tilmann@esc.cam.ac.uk>.  Include the serial number of I<latexdiff>
+(from comments at the top of the source or use B<--version>).  If you come across latex
+files that are error-free and conform to the specifications set out
+above, and whose differencing still does not result in error-free
+latex, please send me those files, ideally edited to only contain the
+offending passage as long as that still reproduces the problem. 
+
+=head1 SEE ALSO
+
+L<latexrevise>
+
+=head1 PORTABILITY
+
+I<latexdiff> does not make use of external commands and thus should run
+on any platform  supporting Perl 5.6 or higher.  If files with encodings 
+other than ASCII or UTF-8 are processed, Perl 5.8 or higher is required.
+
+The standard version of I<latexdiff> requires installation of the Perl package
+C<Algorithm::Diff> (available from I<www.cpan.org> - 
+I<http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15>) but a stand-alone
+version, I<latexdiff-so>, which has this package inlined, is available, too.
+I<latexdiff-fast> requires the I<diff> command to be present.
+
+=head1 AUTHOR
+
+Copyright (C) 2004-2007 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+
+Contributors of fixes and additions: V. Kuhlmann, J. Paisley, N. Becker, T. Doerges, K. Huebner
+Thanks to everyone who send in bug reports.
+
+=cut
+
+__END__
+%%BEGIN SAFE COMMANDS
+% Regex matching commands which can safely be in the
+% argument of a \DIFadd or \DIFdel command (leave out the \)
+arabic
+dashbox
+emph
+fbox
+framebox
+hspace
+math.*
+makebox
+mbox
+pageref
+ref
+symbol
+raisebox
+rule
+text.*
+shortstack
+usebox
+dag
+ddag
+copyright
+pounds
+S
+P
+oe
+OE
+ae
+AE
+aa
+AA
+o
+O
+l
+L
+frac
+ss
+sqrt
+ldots
+cdots
+vdots
+ddots
+alpha
+beta
+gamma
+delta
+epsilon
+varepsilon
+zeta
+eta
+theta
+vartheta
+iota
+kappa
+lambda
+mu
+nu
+xi
+pi
+varpi
+rho
+varrho
+sigma
+varsigma
+tau
+upsilon
+phi
+varphi
+chi
+psi
+omega
+Gamma
+Delta
+Theta
+Lambda
+Xi
+Pi
+Sigma
+Upsilon
+Phi
+Psi
+Omega
+ps
+mp
+times
+div
+ast
+star
+circ
+bullet
+cdot
+cap
+cup
+uplus
+sqcap
+vee
+wedge
+setminus
+wr
+diamond
+(?:big)?triangle.*
+lhd
+rhd
+unlhd
+unrhd
+oplus
+ominus
+otimes
+oslash
+odot
+bigcirc
+d?dagger
+amalg
+leq
+prec
+preceq
+ll
+(?:sq)?su[bp]set(?:eq)?
+in
+vdash
+geq
+succ(?:eq)?
+gg
+ni
+dashv
+equiv
+sim(?:eq)?
+asymp
+approx
+cong
+neq
+doteq
+propto
+models
+perp
+mid
+parallel
+bowtie
+Join
+smile
+frown
+.*arrow
+(?:long)?mapsto
+.*harpoon.*
+leadsto
+aleph
+hbar
+imath
+jmath
+ell
+wp
+Re
+Im
+mho
+prime
+emptyset
+nabla
+surd
+top
+bot
+angle
+forall
+exists
+neg
+flat
+natural
+sharp
+backslash
+partial
+infty
+Box
+Diamond
+triangle
+clubsuit
+diamondsuit
+heartsuit
+spadesuit
+sum
+prod
+coprod
+int
+oint
+big(?:sq)?c[au]p
+bigvee
+bigwedge
+bigodot
+bigotimes
+bigoplus
+biguplus
+(?:arc)?(?:cos|sin|tan|cot)h?
+csc
+arg
+deg
+det
+dim
+exp
+gcd
+hom
+inf
+ker
+lg
+lim
+liminf
+limsup
+ln
+log
+max
+min
+Pr
+sec
+sup
+(SUPER|SUB)SCRIPTNB
+(SUPER|SUB)SCRIPT
+%%END SAFE COMMANDS
+
+%%BEGIN TEXT COMMANDS
+% Regex matching commands with a text argument (leave out the \)
+addcontents.*
+cc
+closing
+chapter
+dashbox
+emph
+encl
+fbox
+framebox
+footnote
+footnotetext
+framebox
+part
+(sub){0,2}section\*?
+(sub)?paragraph\*?
+makebox
+mbox
+opening
+parbox
+raisebox
+savebox
+sbox
+shortstack
+signature
+text.*
+value
+underline
+sqrt
+(SUPER|SUB)SCRIPT
+%%END TEXT COMMANDS 
+
+%%BEGIN CONTEXT1 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+caption
+%%END CONTEXT1 COMMANDS 
+
+%%BEGIN CONTEXT2 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+title
+author
+%%END CONTEXT2 COMMANDS 
+
+
+%% TYPES (Commands for highlighting changed blocks)
+
+%DIF UNDERLINE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue}\uwave{#1}}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}\sout{#1}}}                     
+%DIF END UNDERLINE PREAMBLE
+
+%DIF CTRADITIONAL PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} [..\footnote{removed: #1} ]}}
+%DIF END CTRADITIONAL PREAMBLE
+
+%DIF TRADITIONAL PREAMBLE
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{[..\footnote{removed: #1} ]}}
+%DIF END TRADITIONAL PREAMBLE
+
+%DIF CFONT PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} \scriptsize #1}}
+%DIF END CFONT PREAMBLE
+
+%DIF FONTSTRIKE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{\footnotesize \sout{#1}}}
+%DIF END FONTSTRIKE PREAMBLE
+
+%DIF CCHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}#1}\protect\cbdelete}
+%DIF END CCHANGEBAR PREAMBLE
+
+%DIF CFONTCHBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\sf #1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\scriptsize #1}\protect\cbdelete}
+%DIF END CFONTCHBAR PREAMBLE
+
+%DIF CULINECHBAR PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\uwave{#1}}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\sout{#1}}\protect\cbdelete}
+%DIF END CULINECHBAR PREAMBLE
+
+%DIF CHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\providecommand{\DIFadd}[1]{\protect\cbstart{#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete}
+%DIF END CHANGEBAR PREAMBLE
+
+%DIF INVISIBLE PREAMBLE
+\providecommand{\DIFadd}[1]{#1}
+\providecommand{\DIFdel}[1]{}
+%DIF END INVISIBLE PREAMBLE
+
+
+%% SUBTYPES (Markers for beginning and end of changed blocks)
+
+%DIF SAFE PREAMBLE
+\providecommand{\DIFaddbegin}{}
+\providecommand{\DIFaddend}{}
+\providecommand{\DIFdelbegin}{}
+\providecommand{\DIFdelend}{}
+%DIF END SAFE PREAMBLE
+
+%DIF MARGIN PREAMBLE
+\providecommand{\DIFaddbegin}{\protect\marginpar{a[}}
+\providecommand{\DIFaddend}{\protect\marginpar{]}}
+\providecommand{\DIFdelbegin}{\protect\marginpar{d[}}
+\providecommand{\DIFdelend}{\protect\marginpar{]}}
+%DIF END BRACKET PREAMBLE
+
+%DIF DVIPSCOL PREAMBLE
+%Note: only works with dvips converter
+\RequirePackage{color}
+\RequirePackage{dvipscol}
+\providecommand{\DIFaddbegin}{\protect\nogroupcolor{blue}}
+\providecommand{\DIFaddend}{\protect\nogroupcolor{black}}
+\providecommand{\DIFdelbegin}{\protect\nogroupcolor{red}}
+\providecommand{\DIFdelend}{\protect\nogroupcolor{black}}
+%DIF END DVIPSCOL PREAMBLE
+
+
+%% FLOAT TYPES 
+
+%DIF FLOATSAFE PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%DIF IDENTICAL PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{\DIFaddbegin}
+\providecommand{\DIFaddendFL}{\DIFaddend}
+\providecommand{\DIFdelbeginFL}{\DIFdelbegin}
+\providecommand{\DIFdelendFL}{\DIFdelend}
+%DIF END IDENTICAL PREAMBLE
+
+%DIF TRADITIONALSAFE PREAMBLE
+% procidecommand color to make this work for TRADITIONAL and CTRADITIONAL
+\providecommand{\color}[1]{}
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}[..{\scriptsize {removed: #1}} ]}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%% SPECIAL PACKAGE PREAMBLE COMMANDS
+
+% Standard \DIFadd and \DIFdel are redefined as \DIFaddtex and \DIFdeltex
+% when hyperref package is included.
+%DIF HYPERREF PREAMBLE
+\providecommand{\DIFadd}[1]{\texorpdfstring{\DIFaddtex{#1}}{#1}}
+\providecommand{\DIFdel}[1]{\texorpdfstring{\DIFdeltex{#1}}{}}
+%DIF END HYPERREF PACKAGE
diff --git a/Master/texmf-dist/doc/latex/latexdiff/latexdiff-man.pdf b/Master/texmf-dist/doc/latex/latexdiff/latexdiff-man.pdf
new file mode 100644
index 00000000000..09493af5fe7
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/latexdiff/latexdiff-man.pdf
diff --git a/Master/texmf-dist/scripts/latexdiff/latexdiff-vc b/Master/texmf-dist/scripts/latexdiff/latexdiff-vc
new file mode 100755
index 00000000000..3e9a3f246de
--- /dev/null
+++ b/Master/texmf-dist/scripts/latexdiff/latexdiff-vc
@@ -0,0 +1,430 @@
+#!/usr/bin/perl -w
+# Place the following 2 lines at beginning to make script independent of location of perl
+#eval 'exec perl -w -S $0 ${1+"$@"}'
+#    if 0; # not running under some shell
+#
+# latexdiff-vc  - wrapper script for applying latexdiff to rcs managed files
+#                 and for automatised creation of postscript or pdf from difference file
+#
+#   Copyright (C) 2005  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#   Contributors: S Utcke, H Bruyninckx
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# version 0.25:
+#   - bbl is allowed as alternative extension (instead of .tex)
+#   
+use Getopt::Long ;
+use Pod::Usage qw/pod2usage/ ;
+use File::Temp qw/tempdir/ ;
+use File::Basename qw/dirname/;
+use strict ;
+
+# Option names
+my ($version,$help,$postscript,$pdf,$force,$dir,$cvs,$rcs,$svn,$diffcmd,$patchcmd,@revs);
+# Preset Variables
+my $latexdiff="latexdiff"; # Program for making the comparison
+my $vc="";
+my $tempdir=tempdir(CLEANUP => 1);
+# Variables
+my ($file1,$file2,$diff,$diffbase,$answer,$options,$infile,$append,$dirname,$cwd);
+my (@files,@ldoptions,@tmpfiles,@ptmpfiles,@difffiles); # ,
+
+
+Getopt::Long::Configure('pass_through','bundling');
+
+GetOptions('revision|r:s' => \@revs,
+           'cvs' => \$cvs,
+           'rcs' => \$rcs,
+           'svn' => \$svn,
+           'dir|d:s' => \$dir,
+           'postscript|ps' => \$postscript,
+           'pdf' => \$pdf,
+           'force' => \$force,
+           'version' => \$version,
+	   'help|h' => \$help);
+
+if ( $help ) {
+  pod2usage(1) ;
+}
+
+if ( $version ) {
+  die "This is LATEXDIFF-VC 0.25\n" ;
+}
+
+if ( $cvs ) {
+  $vc="CVS";
+}
+if ( $rcs ) {
+  die "Cannot specify more than one of --cvs, --rcs or --svn." if ($vc);
+  $vc="RCS";
+}
+if ( $svn ) {
+  die "Cannot specify more than one of --cvs, --rcs or --svn." if ($vc);
+  $vc="SVN";
+}
+
+# check whether the first file name got misinterpreted as an option to an empty -r option
+if ( @revs && -f $revs[$#revs] ) {
+  unshift @ARGV,$revs[$#revs];
+  $revs[$#revs]="";
+}
+# check whether the first file name got misinterpreted as an option to an empty -d option
+if ( defined($dir) && -f $dir ) {
+  unshift @ARGV,$dir;
+  $dir="";
+}
+
+$file2=pop @ARGV;
+( defined($file2) && $file2 =~ /\.(tex|bbl)$/ ) or pod2usage("Must specify at least one tex or bbl file");
+
+if (! $vc && scalar(@revs)>0 ) {
+  # have to guess $vc
+  # check whether we have a special name
+  if ( $0 =~ /-cvs$/ ) {
+    $vc="CVS";
+  } elsif ( $0 =~ /-rcs$/ ) {
+    $vc="RCS";
+  } elsif ( $0 =~ /-svn$/ ) {
+    $vc="SVN";
+  } elsif ( -e "CVSROOT" || defined($ENV{"CVSROOT"}) ) {
+    print STDERR "Guess you are using CVS ...\n";
+    $vc="CVS";
+  } elsif ( -e "$file2,v" ) {
+    print STDERR "Guess you are using RCS ...\n";
+    $vc="RCS";
+  } elsif ( -d ".svn" ) {
+    print STDERR "Guess you are using SVN ...\n";
+    $vc="SVN";
+  } else {
+    print STDERR "Cannot figure out version control system, so I default to CVS\n";
+    $vc="CVS";
+  }
+}
+
+if (defined($dir) && $dir=~/^\.\/?/ ) {
+  print STDERR "You wrote selected -dir=.  but you do not really like to do that, do you ?\n";
+  exit 10
+}
+
+if ( scalar(@revs)>0 ) {
+  if ( $vc eq "CVS" ) { 
+    $diffcmd  = "cvs diff -u -r"; 
+    $patchcmd = "patch -R -p0";
+  } elsif ( $vc eq "RCS" ) {
+    $diffcmd  = "rcsdiff -u -r";  
+    $patchcmd = "patch -R -p0";
+  } elsif ( $vc eq "SVN" ) {
+    $diffcmd  = "svn diff -r ";  
+    $patchcmd = "patch -R -p0";
+  } else {
+    print STDERR "Unknown versioning system $vc \n";
+    exit 10;
+  }
+}
+
+
+# make file list (last arguments), initial arguments have to be passed to latexdiff
+# We assume an argument is a valid file rather than a latexdiff argument
+# if it has extension .tex or .bbl
+
+@files=($file2);
+while( $file1=pop @ARGV ) {
+  if ( $file1 =~ /\.(tex|bbl)$/ ) {
+    # $file1 looks like a valid file name and is prepended to file list
+    unshift @files, $file1 ;
+  } else {
+    # $file1 looks like an option for latexdiff, push it back to argument stack
+    unshift @ldoptions, $file1 ;
+  }
+}
+
+if ( scalar(@revs) == 0 ) {
+  pod2usage("When -r option is not used, two .tex files (old and new) must be given on the command line") unless @files==2;
+    #  compare two files
+  $file1=shift @files ;
+}
+
+if ( scalar(@revs) == 2 ) {
+  $append = "-diff$revs[0]-$revs[1]";
+} elsif ( scalar(@revs) == 1 || $revs[0] ) {
+  $append = "-diff$revs[0]";
+} else {
+  $append = "-diff";
+}
+
+if ( defined ($dir) && ! $dir ) {
+  # bare -d option => choose directory name
+  ($dir=$append) =~ s/^-//;
+}
+
+if ( ($vc eq "SVN" || $vc eq "CVS") && scalar(@revs)) {
+  length($revs[$#revs]) > 0 or $revs[$#revs]="HEAD";
+  length($revs[0]) > 0 or $revs[0]="HEAD";
+}
+
+#exit ; 
+
+
+# cycle through all files
+
+@difffiles=();
+while ( $infile=$file2=shift @files ) {
+  print STDERR "Working on  $infile \n";
+  if ( scalar(@revs) == 1 ) {
+    ($file1=$infile) =~ s/\.(tex|bbl)/-oldtmp-$$.$1/ ;
+    push @tmpfiles,$file1;
+    # compare file with previous version ($revs[0]="") or specified version
+    system("$diffcmd$revs[0] $infile| $patchcmd -o$file1") ;
+  } elsif ( scalar(@revs) == 2 ) {
+    ($file1=$infile) =~ s/\.(tex|bbl)/-oldtmp-$$.$1/ ;
+    $file2 =~ s/\.(tex|bbl)/-newtmp-$$.$1/ ;
+    push @tmpfiles,$file2;
+    system("$diffcmd$revs[1] $infile | $patchcmd -o$file2")  ;
+    system("$diffcmd$revs[0] $infile | $patchcmd -o$file1")  ;
+  }
+
+  if ( -z $file1 || -z $file2) {
+    print STDERR "One or both of the files to compare are empty. Possibly something went wrong in the retrieval of older versions. Aborting ...\n" ;
+    exit(10);
+  }
+
+  # Get name of difference file
+  if ( defined($dir) ) {
+    $diff="$dir/$infile" ; 
+  } else {
+    ($diff=$infile) =~ s/\.(tex|bbl)$/$append.$1/ ;
+  }
+  # make directories if needed
+  $dirname=dirname($diff) ;
+  system("mkdir -p $dirname") unless ( -e $dirname );
+
+  # Remaining options are passed to latexdiff
+  $options = join(" ",@ldoptions);
+
+  if ( -e $diff && ! $force ) {
+    print STDERR "OK to overwrite existing file $diff (y/n)? ";
+    $answer = <STDIN> ;
+    unless ($answer =~ /^y/i ) {
+      unlink @tmpfiles;
+      die "Abort ... " ;
+    }
+  }
+  print "Running $latexdiff\n";
+  unless ( system("$latexdiff $options $file1 $file2 > $diff") == 0 ) { 
+    print STDERR  "Something went wrong in $latexdiff. Deleting $diff and abort\n" ; unlink $diff ; exit(5) 
+  };
+  print "Generated difference file $diff\n";
+
+  if ( ( $postscript or $pdf ) and !( scalar(@revs) && greptex( qr/\\document(?:class|style)/ , $diff ) ) ) {
+    # save filename for later processing if postscript or pdf conversion is requested and either two-file mode was used (scalar(@revs)==0) or the diff file contains documentclass statement (ie. is a root document)
+    push @difffiles, $diff ;
+  }
+  
+  unlink @tmpfiles;
+}
+
+foreach $diff ( @difffiles ) {
+  chomp($cwd=(`pwd`));
+  if  (defined($dir)) {
+    ( $diff =~ s/$dir\/?// ) ;
+    chdir $dir ; 
+  }
+  @ptmpfiles=();
+  ( $diffbase=$diff) =~ s/\.(tex)$// ;
+
+  # adapt magically changebar styles to [pdftex] display driver if pdf output was selected
+  if ( $pdf ) {
+    system("sed \"s/Package\\[dvips\\]/Package[pdftex]/\" $diff > $diff.tmp$$ ; \\mv $diff.tmp$$ $diff");
+  }
+  print STDERR "PDF: $pdf Postscript: $postscript cwd $cwd\n";
+
+  if ( system("grep -q \'^[^%]*\\\\bibliography\' $diff") == 0 ) { 
+    if ( $postscript) {
+      system("latex --interaction=batchmode $diff; bibtex $diffbase");
+      push @ptmpfiles, "$diffbase.bbl","$diffbase.bbl" ; 
+    } elsif ( $pdf ) {
+      system("pdflatex --interaction=batchmode $diff; bibtex $diffbase");
+      push @ptmpfiles, "$diffbase.bbl","$diffbase.bbl" ; 
+    }
+  }
+
+  if ( $postscript ) {
+    my $dvi="$diffbase.dvi";
+    my $ps="$diffbase.ps";
+
+    system("latex --interaction=batchmode $diff; latex $diff; dvips -o $ps $dvi");
+    push @ptmpfiles, "$diffbase.aux","$diffbase.log",$dvi ;
+    print "Generated postscript file $ps\n";
+  } 
+  elsif ( $pdf ) {
+    system("pdflatex --interaction=batchmode $diff; pdflatex $diff");
+    push @ptmpfiles, "$diffbase.aux","$diffbase.log";
+  }
+  unlink @ptmpfiles;
+  chdir $cwd;
+}
+
+# greptex returns 1 if regex is not matched in filename
+# 0 if there is a match
+sub greptex {
+  my ($regex,$filename)=@_;
+  my ($i)=0;
+  open (FH, $filename) or die("Couldn't open $filename: $!");
+  while (<FH>) {
+    next if /^\s*%/;    # skip comment lines
+    if ( m/$regex/ ) {
+      close(FH);
+      return(0);
+    }
+    # only scan 25 lines
+    $i++;    
+    last if $i>25 ;
+  }
+  close(FH);
+  return(1);
+}
+
+
+=head1 NAME
+
+latexdiff-vc - wrapper script that calls latexdiff for different versions of a file under version management (CVS, RCS or SVN)
+
+=head1 SYNOPSIS
+
+B<latexdiff-vc> [ F<latexdiff-options> ] [ F<latexdiff-vc-options> ]  B<-r> [F<rev1>] [B<-r> F<rev2>]  F<file1.tex> [ F<file2.tex> ...]
+
+ or
+
+B<latexdiff-vc> [ F<latexdiff-options> ]  [ F<latexdiff-vc-options> ][ B<--postscript> | B<--pdf> ]  F<old.tex> F<new.tex>
+
+=head1 DESCRIPTION
+
+I<latexdiff-vc> is a wrapper script that applies I<latexdiff> to a
+file, or multiple files under version control (CVS or RCS), and optionally runs the
+sequence of C<latex> and C<dvips> or C<pdflatex> commands necessary to
+produce pdf or postscript output of the difference tex file(s). It can
+also be applied to a pair of files to automatise the generation of difference
+file in postscript or pdf format.
+
+=head1 OPTIONS
+
+=over 4
+
+=item B<--rcs>, B<--svn>, or B<--cvs>
+
+Set the version system. 
+If no version system is specified, latexdiff-vc will venture a guess.
+
+latexdiff-cvs and latexdiff-rcs are variants of latexdiff-vc which default to 
+the respective versioning system. However, this default can still be overridden using the options above.
+
+=item B<-r>, B<-r> F<rev> or B<--revision>, B<--revision=>F<rev>
+
+Choose revision (under RCS, CVS or SVN). One or two B<-r> options can be
+specified, and the resulting in different behaviour:
+
+=over 4
+
+=item B<latexdiff-vc> -r F<file.tex> ...
+
+compares F<file.tex> with the most recent version checked into RCS.
+
+=item B<latexdiff-vc> -r F<rev1> F<file.tex> ...
+
+compares F<file.tex> with revision F<rev1>.
+
+=item B<latexdiff-vc> -r F<rev1> -r F<rev2> F<file.tex> ...
+
+compares revisions F<rev1> and F<rev2> of F<file.tex>.
+
+Multiple files can be specified for all of the above options. All files must have the
+extension C<.tex>, though.
+
+=item B<latexdiff-vc>  F<old.tex> F<new.tex>
+
+compares two files.
+
+=back
+
+The name of the difference file is generated automatically and
+reported to stdout.
+
+=item B<-d> or B<--dir>  B<-d> F<path> or B<--dir=>F<path>
+
+Rather than appending the string C<diff> and optionally the version
+numbers given to the output-file, this will prepend a directory name C<diff> 
+to the
+original filename, creating the directory and subdirectories should they not exist already.  This is particularly useful in order to clone a
+complete directory hierarchy.  Optionally, a pathname F<path> can be specified, which is prepended instead of C<diff>.
+
+=item B<--ps> or B<--postscript>
+
+Generate postscript output from difference file.  This will run the
+sequence C<latex; latex; dvips> on the difference file (do not use
+this option in the rare cases, where three C<latex> commands are
+required if you care about correct referencing).  If the difference
+file contains a C<\bibliography> tag, run the sequence C<latex;
+bibtex; latex; latex; dvips>.
+
+=item B<--pdf>
+
+Generate pdf output from difference file using C<pdflatex>. This will
+run the sequence C<pdflatex; pdflatex> on the difference file, or
+C<pdflatex; bibtex; pdflatex; pdflatex> for files requiring bibtex.
+
+=item B<--force>
+
+Overwrite existing diff files without asking for confirmation. Default 
+behaviour is to ask for confirmation before overwriting an existing difference
+file.
+
+=item B<--help> or
+B<-h>
+
+Show help text
+
+=item B<--version>
+
+Show version number
+
+=back
+
+All other options are passed on to C<latexdiff>.
+
+=head1 SEE ALSO
+
+L<latexdiff>
+
+=head1 PORTABILITY
+
+I<latexdiff-vc> uses external commands and is therefore
+limited to Unix-like systems. It also requires the RCS version control
+system and latex to be installed on the system.  Modules from Perl 5.8
+or higher are required.
+
+
+=head1 AUTHOR
+
+Copyright (C) 2005 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+Contributors: S Utcke, H Bruyninckx
+
+=cut
+
diff --git a/Master/texmf-dist/scripts/latexdiff/latexdiff.pl b/Master/texmf-dist/scripts/latexdiff/latexdiff.pl
new file mode 100755
index 00000000000..03c70c3ac4e
--- /dev/null
+++ b/Master/texmf-dist/scripts/latexdiff/latexdiff.pl
@@ -0,0 +1,3240 @@
+#!/usr/bin/perl -w
+# latexdiff - differences two latex files on the word level
+#             and produces a latex file with the differences marked up.
+#
+#   Copyright (C) 2004-2007  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# Version 0.5  A number of minor improvements based on feedback
+#              Deleted blocks are now shown before added blocks
+#              Package specific processing
+#
+# Version 0.43 unreleased typo in list of styles at the end
+#              Add protect to all \cbstart, \cbend commands
+#              More robust substitution of deleted math commands
+#
+# Version 0.42 November 06  Bug fixes only
+#
+# Version 0.4   March 06 option for fast differencing using UNIX diff command, several minor bug fixes (\par bug, improved highlighting of textcmds)
+#
+# Version 0.3   August 05 improved parsing of displayed math, --allow-spaces 
+#               option, several minor bug fixes
+#
+# Version 0.25  October 04 Fix bug with deleted equations, add math mode commands to safecmd, add | to allowed interpunctuation signs
+# Version 0.2   September 04 extension to utf-8 and variable encodings
+# Version 0.1   August 04    First public release
+
+# Inserted block for stand-alone version replaces
+# use Algorithm::Diff qw(traverse_sequences);
+# in standard version
+# The following BEGIN block contains a verbatim copy of
+# Ned Konz' Algorithm::Diff package version 1.15 except
+# that all POD documentation has been stripped out.
+# I encourage you to download and install the Algorithm::Diff
+# package and use the standard latexdiff version instead
+# (current distribution available from http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15
+#  the most recent version can be found via  http://search.cpan.org/search?module=Algorithm::Diff )
+# Please note that the LICENCSE for Algorithm::Diff :
+#   "Copyright (c) 2000-2002 Ned Konz.  All rights reserved.
+#    This program is free software;
+#    you can redistribute it and/or modify it under the same terms
+#    as Perl itself."
+# The stand-alone version of latexdiff is provided as a convenience
+# for latex users with no knowledge of PERL who do not wish to install
+# additional packages to be able to use latexdiff.  If you believe
+# the inlining of Algorithm::Diff violates its license please contact
+# me and I will modify the latexdiff distribution accordingly.
+# Frederik Tilmann (tilmann@esc.cam.ac.uk)
+BEGIN { 
+package Algorithm::Diff;
+use strict;
+use vars qw($VERSION @EXPORT_OK @ISA @EXPORT);
+use integer;    # see below in _replaceNextLargerWith() for mod to make
+                # if you don't use this
+require Exporter;
+@ISA       = qw(Exporter);
+@EXPORT    = qw();
+@EXPORT_OK = qw(LCS diff traverse_sequences traverse_balanced sdiff);
+$VERSION = sprintf('%d.%02d so', (q$Revision: 1.15 $ =~ /\d+/g));
+
+# McIlroy-Hunt diff algorithm
+# Adapted from the Smalltalk code of Mario I. Wolczko, <mario@wolczko.com>
+# by Ned Konz, perl@bike-nomad.com
+
+
+# Create a hash that maps each element of $aCollection to the set of positions
+# it occupies in $aCollection, restricted to the elements within the range of
+# indexes specified by $start and $end.
+# The fourth parameter is a subroutine reference that will be called to
+# generate a string to use as a key.
+# Additional parameters, if any, will be passed to this subroutine.
+#
+# my $hashRef = _withPositionsOfInInterval( \@array, $start, $end, $keyGen );
+
+sub _withPositionsOfInInterval
+{
+	my $aCollection = shift;    # array ref
+	my $start       = shift;
+	my $end         = shift;
+	my $keyGen      = shift;
+	my %d;
+	my $index;
+	for ( $index = $start ; $index <= $end ; $index++ )
+	{
+		my $element = $aCollection->[$index];
+		my $key = &$keyGen( $element, @_ );
+		if ( exists( $d{$key} ) )
+		{
+			unshift ( @{ $d{$key} }, $index );
+		}
+		else
+		{
+			$d{$key} = [$index];
+		}
+	}
+	return wantarray ? %d : \%d;
+}
+
+# Find the place at which aValue would normally be inserted into the array. If
+# that place is already occupied by aValue, do nothing, and return undef. If
+# the place does not exist (i.e., it is off the end of the array), add it to
+# the end, otherwise replace the element at that point with aValue.
+# It is assumed that the array's values are numeric.
+# This is where the bulk (75%) of the time is spent in this module, so try to
+# make it fast!
+
+sub _replaceNextLargerWith
+{
+	my ( $array, $aValue, $high ) = @_;
+	$high ||= $#$array;
+
+	# off the end?
+	if ( $high == -1 || $aValue > $array->[-1] )
+	{
+		push ( @$array, $aValue );
+		return $high + 1;
+	}
+
+	# binary search for insertion point...
+	my $low = 0;
+	my $index;
+	my $found;
+	while ( $low <= $high )
+	{
+		$index = ( $high + $low ) / 2;
+
+		#		$index = int(( $high + $low ) / 2);		# without 'use integer'
+		$found = $array->[$index];
+
+		if ( $aValue == $found )
+		{
+			return undef;
+		}
+		elsif ( $aValue > $found )
+		{
+			$low = $index + 1;
+		}
+		else
+		{
+			$high = $index - 1;
+		}
+	}
+
+	# now insertion point is in $low.
+	$array->[$low] = $aValue;    # overwrite next larger
+	return $low;
+}
+
+# This method computes the longest common subsequence in $a and $b.
+
+# Result is array or ref, whose contents is such that
+# 	$a->[ $i ] == $b->[ $result[ $i ] ]
+# foreach $i in ( 0 .. $#result ) if $result[ $i ] is defined.
+
+# An additional argument may be passed; this is a hash or key generating
+# function that should return a string that uniquely identifies the given
+# element.  It should be the case that if the key is the same, the elements
+# will compare the same. If this parameter is undef or missing, the key
+# will be the element as a string.
+
+# By default, comparisons will use "eq" and elements will be turned into keys
+# using the default stringizing operator '""'.
+
+# Additional parameters, if any, will be passed to the key generation routine.
+
+sub _longestCommonSubsequence
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $keyGen = shift;    # code ref
+	my $compare;           # code ref
+
+	# set up code refs
+	# Note that these are optimized.
+	if ( !defined($keyGen) )    # optimize for strings
+	{
+		$keyGen = sub { $_[0] };
+		$compare = sub { my ( $a, $b ) = @_; $a eq $b };
+	}
+	else
+	{
+		$compare = sub {
+			my $a = shift;
+			my $b = shift;
+			&$keyGen( $a, @_ ) eq &$keyGen( $b, @_ );
+		};
+	}
+
+	my ( $aStart, $aFinish, $bStart, $bFinish, $matchVector ) =
+	  ( 0, $#$a, 0, $#$b, [] );
+
+	# First we prune off any common elements at the beginning
+	while ( $aStart <= $aFinish
+		and $bStart <= $bFinish
+		and &$compare( $a->[$aStart], $b->[$bStart], @_ ) )
+	{
+		$matchVector->[ $aStart++ ] = $bStart++;
+	}
+
+	# now the end
+	while ( $aStart <= $aFinish
+		and $bStart <= $bFinish
+		and &$compare( $a->[$aFinish], $b->[$bFinish], @_ ) )
+	{
+		$matchVector->[ $aFinish-- ] = $bFinish--;
+	}
+
+	# Now compute the equivalence classes of positions of elements
+	my $bMatches =
+	  _withPositionsOfInInterval( $b, $bStart, $bFinish, $keyGen, @_ );
+	my $thresh = [];
+	my $links  = [];
+
+	my ( $i, $ai, $j, $k );
+	for ( $i = $aStart ; $i <= $aFinish ; $i++ )
+	{
+		$ai = &$keyGen( $a->[$i], @_ );
+		if ( exists( $bMatches->{$ai} ) )
+		{
+			$k = 0;
+			for $j ( @{ $bMatches->{$ai} } )
+			{
+
+				# optimization: most of the time this will be true
+				if ( $k and $thresh->[$k] > $j and $thresh->[ $k - 1 ] < $j )
+				{
+					$thresh->[$k] = $j;
+				}
+				else
+				{
+					$k = _replaceNextLargerWith( $thresh, $j, $k );
+				}
+
+				# oddly, it's faster to always test this (CPU cache?).
+				if ( defined($k) )
+				{
+					$links->[$k] =
+					  [ ( $k ? $links->[ $k - 1 ] : undef ), $i, $j ];
+				}
+			}
+		}
+	}
+
+	if (@$thresh)
+	{
+		for ( my $link = $links->[$#$thresh] ; $link ; $link = $link->[0] )
+		{
+			$matchVector->[ $link->[1] ] = $link->[2];
+		}
+	}
+
+	return wantarray ? @$matchVector : $matchVector;
+}
+
+sub traverse_sequences
+{
+	my $a                 = shift;                                  # array ref
+	my $b                 = shift;                                  # array ref
+	my $callbacks         = shift || {};
+	my $keyGen            = shift;
+	my $matchCallback     = $callbacks->{'MATCH'} || sub { };
+	my $discardACallback  = $callbacks->{'DISCARD_A'} || sub { };
+	my $finishedACallback = $callbacks->{'A_FINISHED'};
+	my $discardBCallback  = $callbacks->{'DISCARD_B'} || sub { };
+	my $finishedBCallback = $callbacks->{'B_FINISHED'};
+	my $matchVector = _longestCommonSubsequence( $a, $b, $keyGen, @_ );
+
+	# Process all the lines in @$matchVector
+	my $lastA = $#$a;
+	my $lastB = $#$b;
+	my $bi    = 0;
+	my $ai;
+
+	for ( $ai = 0 ; $ai <= $#$matchVector ; $ai++ )
+	{
+		my $bLine = $matchVector->[$ai];
+		if ( defined($bLine) )    # matched
+		{
+			&$discardBCallback( $ai, $bi++, @_ ) while $bi < $bLine;
+			&$matchCallback( $ai,    $bi++, @_ );
+		}
+		else
+		{
+			&$discardACallback( $ai, $bi, @_ );
+		}
+	}
+
+	# The last entry (if any) processed was a match.
+	# $ai and $bi point just past the last matching lines in their sequences.
+
+	while ( $ai <= $lastA or $bi <= $lastB )
+	{
+
+		# last A?
+		if ( $ai == $lastA + 1 and $bi <= $lastB )
+		{
+			if ( defined($finishedACallback) )
+			{
+				&$finishedACallback( $lastA, @_ );
+				$finishedACallback = undef;
+			}
+			else
+			{
+				&$discardBCallback( $ai, $bi++, @_ ) while $bi <= $lastB;
+			}
+		}
+
+		# last B?
+		if ( $bi == $lastB + 1 and $ai <= $lastA )
+		{
+			if ( defined($finishedBCallback) )
+			{
+				&$finishedBCallback( $lastB, @_ );
+				$finishedBCallback = undef;
+			}
+			else
+			{
+				&$discardACallback( $ai++, $bi, @_ ) while $ai <= $lastA;
+			}
+		}
+
+		&$discardACallback( $ai++, $bi, @_ ) if $ai <= $lastA;
+		&$discardBCallback( $ai, $bi++, @_ ) if $bi <= $lastB;
+	}
+
+	return 1;
+}
+
+sub traverse_balanced
+{
+	my $a                 = shift;                                  # array ref
+	my $b                 = shift;                                  # array ref
+	my $callbacks         = shift || {};
+	my $keyGen            = shift;
+	my $matchCallback     = $callbacks->{'MATCH'} || sub { };
+	my $discardACallback  = $callbacks->{'DISCARD_A'} || sub { };
+	my $discardBCallback  = $callbacks->{'DISCARD_B'} || sub { };
+	my $changeCallback    = $callbacks->{'CHANGE'};
+	my $matchVector = _longestCommonSubsequence( $a, $b, $keyGen, @_ );
+
+	# Process all the lines in match vector
+	my $lastA = $#$a;
+	my $lastB = $#$b;
+	my $bi    = 0;
+	my $ai    = 0;
+	my $ma    = -1;
+	my $mb;
+
+	while (1)
+	{
+
+		# Find next match indices $ma and $mb
+		do { $ma++ } while ( $ma <= $#$matchVector && !defined $matchVector->[$ma] );
+
+		last if $ma > $#$matchVector;    # end of matchVector?
+		$mb = $matchVector->[$ma];
+
+		# Proceed with discard a/b or change events until
+		# next match
+		while ( $ai < $ma || $bi < $mb )
+		{
+
+			if ( $ai < $ma && $bi < $mb )
+			{
+
+				# Change
+				if ( defined $changeCallback )
+				{
+					&$changeCallback( $ai++, $bi++, @_ );
+				}
+				else
+				{
+					&$discardACallback( $ai++, $bi, @_ );
+					&$discardBCallback( $ai, $bi++, @_ );
+				}
+			}
+			elsif ( $ai < $ma )
+			{
+				&$discardACallback( $ai++, $bi, @_ );
+			}
+			else
+			{
+
+				# $bi < $mb
+				&$discardBCallback( $ai, $bi++, @_ );
+			}
+		}
+
+		# Match
+		&$matchCallback( $ai++, $bi++, @_ );
+	}
+
+	while ( $ai <= $lastA || $bi <= $lastB )
+	{
+		if ( $ai <= $lastA && $bi <= $lastB )
+		{
+
+			# Change
+			if ( defined $changeCallback )
+			{
+				&$changeCallback( $ai++, $bi++, @_ );
+			}
+			else
+			{
+				&$discardACallback( $ai++, $bi, @_ );
+				&$discardBCallback( $ai, $bi++, @_ );
+			}
+		}
+		elsif ( $ai <= $lastA )
+		{
+			&$discardACallback( $ai++, $bi, @_ );
+		}
+		else
+		{
+
+			# $bi <= $lastB
+			&$discardBCallback( $ai, $bi++, @_ );
+		}
+	}
+
+	return 1;
+}
+
+sub LCS
+{
+	my $a = shift;                                           # array ref
+	my $matchVector = _longestCommonSubsequence( $a, @_ );
+	my @retval;
+	my $i;
+	for ( $i = 0 ; $i <= $#$matchVector ; $i++ )
+	{
+		if ( defined( $matchVector->[$i] ) )
+		{
+			push ( @retval, $a->[$i] );
+		}
+	}
+	return wantarray ? @retval : \@retval;
+}
+
+sub diff
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $retval = [];
+	my $hunk   = [];
+	my $discard = sub { push ( @$hunk, [ '-', $_[0], $a->[ $_[0] ] ] ) };
+	my $add = sub { push ( @$hunk, [ '+', $_[1], $b->[ $_[1] ] ] ) };
+	my $match = sub { push ( @$retval, $hunk ) if scalar(@$hunk); $hunk = [] };
+	traverse_sequences( $a, $b,
+		{ MATCH => $match, DISCARD_A => $discard, DISCARD_B => $add }, @_ );
+	&$match();
+	return wantarray ? @$retval : $retval;
+}
+
+sub sdiff
+{
+	my $a      = shift;    # array ref
+	my $b      = shift;    # array ref
+	my $retval = [];
+	my $discard = sub { push ( @$retval, [ '-', $a->[ $_[0] ], "" ] ) };
+	my $add = sub { push ( @$retval, [ '+', "", $b->[ $_[1] ] ] ) };
+	my $change = sub {
+		push ( @$retval, [ 'c', $a->[ $_[0] ], $b->[ $_[1] ] ] );
+	};
+	my $match = sub {
+		push ( @$retval, [ 'u', $a->[ $_[0] ], $b->[ $_[1] ] ] );
+	};
+	traverse_balanced(
+		$a,
+		$b,
+		{
+			MATCH     => $match,
+			DISCARD_A => $discard,
+			DISCARD_B => $add,
+			CHANGE    => $change,
+		},
+		@_
+	);
+	return wantarray ? @$retval : $retval;
+}
+
+1;
+}
+import Algorithm::Diff qw(traverse_sequences);
+# End of inserted block for stand-alone version
+
+use Getopt::Long ;
+use strict ;
+use utf8 ;
+
+my ($algodiffversion)=split(/ /,$Algorithm::Diff::VERSION);
+
+
+my ($versionstring)=<<EOF ;
+This is LATEXDIFF 0.5  (Algorithm::Diff $Algorithm::Diff::VERSION)
+  (c) 2004-2007 F J Tilmann
+EOF
+
+# Configuration variables: these have to be visible from the subroutines
+my $MINWORDSBLOCK=3; # minimum number of tokens to form an independent block
+                     # shorter identical blocks will be merged to the previous word
+my $FLOATENV='(?:figure|table|plate)[\w\d*@]*' ;   # Environments in which FL variants of defined commands are used
+my $PICTUREENV='(?:picture|DIFnomarkup)[\w\d*@]*' ;   # Environments in which all change markup is removed
+my $MATHENV='(?:equation|displaymath|DOLLARDOLLAR)' ;           # Environments turning on display math mode (code also knows about \[ and \]
+my $MATHREPL='displaymath';  # Environment introducing deleted maths blocks
+my $MATHARRENV='(?:eqnarray|align|gather|multiline|flalign)[*]?' ;           # Environments turning on eqnarray math mode
+my $MATHARRREPL='eqnarray*';  # Environment introducing deleted maths blocks
+my $ARRENV='(?:array|[pbvBV]matrix)'; # Enviroments making arrays in math mode.  The underlining style does not cope well with those - as a result in-text math environments are surrounded by \mbox{ } if any of these commands is used in an inline math block
+my $COUNTERCMD='(?:footnote|part|section|subsection|subsubsection|paragraph|subparagraph)';  # textcmds which are associated with a counter
+                                        # If any of these commands occur in a deleted block
+                                        # they will be succeeded by an \addtocounter{...}{-1}
+                                        # for the associated counter such that the overall numbers
+                                        # should be the same as in the new file
+
+# Markup strings
+# If at all possible, do not change these as parts of the program
+# depend on the actual name (particularly post-processing)
+# At the very least adapt subroutine postprocess to new tokens.
+my $ADDMARKOPEN='\DIFaddbegin ';   # Token to mark begin of appended text
+my $ADDMARKCLOSE='\DIFaddend ';   # Token to mark end of appended text
+my $ADDOPEN='\DIFadd{';  # To mark begin of added text passage
+my $ADDCLOSE='}';        # To mark end of added text passage
+my $ADDCOMMENT='DIF > ';   # To mark added comment line
+my $DELMARKOPEN='\DIFdelbegin ';   # Token to mark begin of deleted text
+my $DELMARKCLOSE='\DIFdelend ';   # Token to mark end of deleted text
+my $DELOPEN='\DIFdel{';  # To mark begin of deleted text passage
+my $DELCLOSE='}';        # To mark end of deleted text passage
+my $DELCMDOPEN='%DIFDELCMD < ';  # To mark begin of deleted commands (must begin with %, i.e., be a comment
+my $DELCMDCLOSE="%%%\n";    # To mark end of deleted commands (must end with a new line)
+my $AUXCMD='%DIFAUXCMD' ; #  follows auxiliary commands put in by latexdiff to make difference file legal
+                          # auxiliary commands must be on a line of their own
+my $DELCOMMENT='DIF < ';   # To mark deleted comment line
+
+
+# main local variables:
+my @TEXTCMDLIST=();  # array containing patterns of commands with text arguments
+my @TEXTCMDEXCL=();  # array containing patterns of commands without text arguments (if a pattern
+                     # matches both TEXTCMDLIST and TEXTCMDEXCL it is excluded)
+my @CONTEXT1CMDLIST=();  # array containing patterns of commands with text arguments (subset of text commands),
+                         # but which cause confusion if used out of context (e.g. \caption). 
+                         # In deleted passages, the command will be disabled but its argument is marked up
+                         # Otherwise they behave exactly like TEXTCMD's 
+my @CONTEXT1CMDEXCL=();  # exclude list for above, but always empty
+my @CONTEXT2CMDLIST=();  # array containing patterns of commands with text arguments, but which fail cause confusion
+                         # if used out of context (e.g. \title). They and their arguments will be disabled in deleted
+                         # passages
+my @CONTEXT2CMDEXCL=();  # exclude list for above, but always empty
+
+my @SAFECMDLIST=();  # array containing patterns of safe commands (which do not break when in the argument of DIFadd or DIFDEL)
+my @SAFECMDEXCL=();
+
+my ($i,$j,$l);
+my ($old,$new);
+my ($line);
+my ($newpreamble,$oldpreamble);
+my (@newpreamble,@oldpreamble,@diffpreamble,@diffbody);
+my ($latexdiffpreamble);
+my ($oldbody, $newbody, $diffbo);
+my ($oldpost, $newpost);
+my ($diffall);
+# Option names
+my ($type,$subtype,$floattype,$config,$preamblefile,$encoding,
+    $showpreamble,$showsafe,$showtext,$showconfig,$showall,
+    $replacesafe,$appendsafe,$excludesafe,
+    $replacetext,$appendtext,$excludetext,
+    $replacecontext1,$appendcontext1,
+    $replacecontext2,$appendcontext2,
+    $help,$verbose,$version,$ignorewarnings,$allowspaces,$flatten,$debug);
+my (@configlist,
+    @appendsafelist,@excludesafelist,
+    @appendtextlist,@excludetextlist,
+    @appendcontext1list,@appendcontext2list,
+    @packagelist);
+my ($assign,@config);
+# Hash where keys corresponds to the names of  all included packages (including the documentclass as another package
+# the optional arguments to the package are the values of the hash elements
+my ($pkg,%packages);
+# Defaults
+$type='UNDERLINE';
+$subtype='SAFE';
+$floattype='FLOATSAFE';
+
+$verbose=0;
+$debug=1; 
+# define character properties
+sub IsNonAsciiPunct { return <<'END'    # Unicode punctuation but excluding ASCII punctuation
++utf8::IsPunct
+-utf8::IsASCII
+END
+}
+sub IsNonAsciiS { return <<'END'       # Unicode symbol but excluding ASCII
++utf8::IsS
+-utf8::IsASCII
+END
+}
+
+
+
+  my %verbhash;
+
+Getopt::Long::Configure('bundling');
+GetOptions('type|t=s' => \$type, 
+	   'subtype|s=s' => \$subtype, 
+	   'floattype|f=s' => \$floattype, 
+	   'config|c=s' => \@configlist,
+	   'preamble|p=s' => \$preamblefile,
+	   'encoding|e=s' => \$encoding,
+	   'exclude-safecmd|A=s' => \@excludesafelist,
+	   'replace-safecmd=s' => \$replacesafe,
+	   'append-safecmd|a=s' => \@appendsafelist,
+	   'exclude-textcmd|X=s' => \@excludetextlist,
+	   'replace-textcmd=s' => \$replacetext,
+	   'append-textcmd|x=s' => \@appendtextlist,
+	   'replace-context1cmd=s' => \$replacecontext1,
+	   'append-context1cmd=s' => \@appendcontext1list,
+	   'replace-context2cmd=s' => \$replacecontext2,
+	   'append-context2cmd=s' => \@appendcontext2list,
+	   'show-preamble' => \$showpreamble,
+	   'show-safecmd' => \$showsafe,
+	   'show-textcmd' => \$showtext,
+	   'show-config' => \$showconfig,
+	   'show-all' => \$showall,
+           'packages=s' => \@packagelist,
+	   'verbose|V' => \$verbose,
+	   'ignore-warnings' => \$ignorewarnings,
+	   'allow-spaces' => \$allowspaces,
+	   'flatten' => \$flatten,
+	   'version' => \$version,
+	   'help|h|H' => \$help);
+
+if ( $help ) {
+  usage() ;
+}
+
+
+if ( $version ) {
+  die $versionstring ; 
+}
+
+print STDERR $versionstring if $verbose; 
+
+if (defined($showall)){
+  $showpreamble=$showsafe=$showtext=$showconfig=1;
+}
+
+# setting extra preamble commands
+if (defined($preamblefile)) {
+  $latexdiffpreamble=join "\n",(extrapream($preamblefile),"");
+} else {
+  $latexdiffpreamble=join "\n",(extrapream($type,$subtype,$floattype),"");
+}
+
+# setting up @SAFECMDLIST and @SAFECMDEXCL
+if (defined($replacesafe)) {
+  init_regex_arr_ext(\@SAFECMDLIST,$replacesafe);
+} else {
+  init_regex_arr_data(\@SAFECMDLIST, "SAFE COMMANDS");
+}
+foreach $appendsafe ( @appendsafelist ) {
+  init_regex_arr_ext(\@SAFECMDLIST, $appendsafe);
+}
+foreach $excludesafe ( @excludesafelist ) {
+  init_regex_arr_ext(\@SAFECMDEXCL, $excludesafe);
+}
+
+# Special: treat all cite commands as safe except in UNDERLINE and FONTSTRIKE mode
+# (there is a conflict between citation and ulem package, see
+# package documentation)
+if ( uc($type) ne "UNDERLINE" && uc($type) ne "FONTSTRIKE" && uc($type) ne "CULINECHBAR" ) {
+  push (@SAFECMDLIST, qr/^cite.*$/);
+}
+
+# setting up @TEXTCMDLIST and @TEXTCMDEXCL
+if (defined($replacetext)) {
+  init_regex_arr_ext(\@TEXTCMDLIST,$replacetext);
+} else {
+  init_regex_arr_data(\@TEXTCMDLIST, "TEXT COMMANDS");
+}
+foreach $appendtext ( @appendtextlist ) {
+  init_regex_arr_ext(\@TEXTCMDLIST, $appendtext);
+}
+foreach $excludetext ( @excludetextlist ) {
+  init_regex_arr_ext(\@TEXTCMDEXCL, $excludetext);
+}
+
+
+# setting up @CONTEXT1CMDLIST ( @CONTEXT1CMDEXCL exist but is always empty )
+if (defined($replacecontext1)) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST,$replacecontext1);
+} else {
+  init_regex_arr_data(\@CONTEXT1CMDLIST, "CONTEXT1 COMMANDS");
+}
+foreach $appendcontext1 ( @appendcontext1list ) {
+  init_regex_arr_ext(\@CONTEXT1CMDLIST, $appendcontext1);
+}
+
+
+# setting up @CONTEXT2CMDLIST ( @CONTEXT2CMDEXCL exist but is always empty )
+if (defined($replacecontext2)) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST,$replacecontext2);
+} else {
+  init_regex_arr_data(\@CONTEXT2CMDLIST, "CONTEXT2 COMMANDS");
+}
+foreach $appendcontext2 ( @appendcontext2list ) {
+  init_regex_arr_ext(\@CONTEXT2CMDLIST, $appendcontext2);
+}
+
+
+
+
+# setting configuration variables
+@config=();
+foreach $config ( @configlist ) {
+  if (-f $config ) {
+    open(FILE,$config) or die ("Couldn't open configuration file $config: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@config,$_);
+    }
+    close(FILE);
+  }
+  else {
+#    foreach ( split(",",$config) ) {
+#      push @config,$_;
+#    }
+     push @config,split(",",$config)
+  }
+}
+foreach $assign ( @config ) {
+  $assign=~ m/\s*(\w*)\s*=\s*(\S*)\s*$/ or die "Illegal assignment $assign in configuration list (must be variable=value)";  
+  if ( $1 eq "MINWORDSBLOCK" ) { $MINWORDSBLOCK = $2; }
+  elsif ( $1 eq "FLOATENV" ) { $FLOATENV = $2 ; }
+  elsif ( $1 eq "PICTUREENV" ) { $PICTUREENV = $2 ; }
+  elsif ( $1 eq "MATHENV" ) { $MATHENV = $2 ; }
+  elsif ( $1 eq "MATHREPL" ) { $MATHREPL = $2 ; }
+  elsif ( $1 eq "MATHARRENV" ) { $MATHARRENV = $2 ; }
+  elsif ( $1 eq "MATHARRREPL" ) { $MATHARRREPL = $2 ; }
+  elsif ( $1 eq "ARRENV" ) { $ARRENV = $2 ; }
+  elsif ( $1 eq "COUNTERCMD" ) { $COUNTERCMD = $2 ; }
+  else { die "Unknown variable $1 in assignment.";}
+}
+
+
+foreach $pkg ( @packagelist ) {
+  map { $packages{$_}="" } split(/,/,$pkg) ;
+}
+
+if ($showpreamble) {
+  print "\nPreamble commands:\n";
+  print $latexdiffpreamble ;
+}
+
+if ($showsafe) {
+  print "\nCommands safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE (unless excluded):\n";
+  print_regex_arr(@SAFECMDLIST);
+  print "\nCommands not safe within scope of $ADDOPEN $ADDCLOSE and $DELOPEN $DELCLOSE :\n";
+  print_regex_arr(@SAFECMDEXCL);
+}
+
+if ($showtext) {
+  print "\nCommands with last argument textual (unless excluded) and safe in every context:\n";
+  print_regex_arr(@TEXTCMDLIST);
+  print "\nContext1 commands (last argument textual, command will be disabled in deleted passages, last argument will be shown as plain text):\n";
+  print_regex_arr(@CONTEXT1CMDLIST);
+  print "\nContext2 commands (last argument textual, command ant its argument will be disabled in deleted passages):\n";
+  print_regex_arr(@CONTEXT2CMDLIST);  
+  print "\nExclude list of Commands with last argument not textual (overrides patterns above):\n";
+  print_regex_arr(@TEXTCMDEXCL);
+}
+
+if ($showconfig) {
+  print "Configuration variables:\n";
+  print "MINWORDSBLOCK=$MINWORDSBLOCK\n";
+  print "FLOATENV=$FLOATENV\n";
+  print "PICTUREENV=$PICTUREENV\n";
+  print "MATHENV=$MATHENV\n";
+  print "MATHREPL=$MATHREPL\n";
+  print "MATHARRENV=$MATHARRENV\n";
+  print "MATHARRREPL=$MATHARRREPL\n";
+  print "ARRENV=$ARRENV\n";
+  print "COUNTERCMD=$COUNTERCMD\n";
+}
+if ($showconfig || $showtext || $showsafe || $showpreamble) {
+  exit 0; }
+if ( @ARGV != 2 ) { 
+  print STDERR "2 and only 2 non-option arguments required.  Write latexdiff -h to get help\n";
+  exit(2);
+}
+
+# Are extra spaces between command arguments permissible?
+my $extraspace;
+if ($allowspaces) {
+  $extraspace='\s*'; 
+} else {
+  $extraspace='';
+}
+
+# append context lists to text lists (as text property is implied)
+push @TEXTCMDLIST, @CONTEXT1CMDLIST;
+push @TEXTCMDLIST, @CONTEXT2CMDLIST;
+
+
+# Patterns. These are used by some of the subroutines, too
+# I can only define them down here because value of extraspace depends on an option
+  my $pat0 = '(?:[^{}]|\\\{|\\\})*';
+  my $pat1 = '(?:[^{}]|\\\{|\\\}|\{'.$pat0.'\})*';
+  my $pat2 = '(?:[^{}]|\\\{|\\\}|\{'.$pat1.'\})*'; # 
+  my $pat3 = '(?:[^{}]|\\\{|\\\}|\{'.$pat2.'\})*';
+  my $pat4 = '(?:[^{}]|\\\{|\\\}|\{'.$pat3.'\})*';
+  my $brat0 = '(?:[^\[\]]|\\\[|\\\])*'; 
+
+  my $quotemarks = '(?:\'\')|(?:\`\`)';
+  my $punct='[0.,\/\'\`:;\"\?\(\)\[\]!~\p{IsNonAsciiPunct}\p{IsNonAsciiS}]';
+  my $number='-?\d*\.\d*';
+  my $mathpunct='[+=<>\-\|]';
+  my $and = '&';
+  my $coords= '[\-.,\s\d]*';
+# word: sequence of letters or accents followed by letter
+  my $word='(?:[-\w\d*]|\\\\[\"\'\`~^][A-Za-z\*])+';
+  my $cmdleftright='\\\\(?:left|right)\s*(?:[()\[\]|]|\\\\(?:[|{}]|\w+))';
+
+  my $cmdoptseq='\\\\[\w\d\*]+'.$extraspace.'(?:(?:\['.$brat0.'\]|\{'. $pat4 . '\}|\(' . $coords .'\))'.$extraspace.')*';
+  my $oneletcmd='\\\\.(?:\['.$brat0.'\]|\{'. $pat4 . '\})*';
+  my $math='\$(?:[^$]|\\\$)*?\$|\\\\[(].*?\\\\[)]';
+#  my $math='\$(?:[^$]|\\\$)*\$';
+  my $comment='%.*?\n';
+  my $pat=qr/(?:\A\s*)?(?:${and}|${quotemarks}|${number}|${word}|$cmdleftright|${cmdoptseq}|${math}|${oneletcmd}|${comment}|${punct}|${mathpunct}|\{|\})\s*/ ;
+
+
+
+# now we are done setting up and can start working   
+my ($oldfile, $newfile) = @ARGV;
+
+$encoding=guess_encoding($newfile) unless defined($encoding);
+
+$encoding = "utf8" if $encoding =~ m/^utf8/i ;
+if (lc($encoding) eq "utf8" ) {
+  binmode(STDOUT, ":utf8");
+  binmode(STDERR, ":utf8");
+}
+
+$old=read_file_with_encoding($oldfile,$encoding);
+$new=read_file_with_encoding($newfile,$encoding);
+
+
+
+
+# reset time
+exetime(1);
+($oldpreamble,$oldbody,$oldpost)=splitdoc($old,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+($newpreamble,$newbody,$newpost)=splitdoc($new,'\\\\begin\{document\}','\\\\end\{document\}');
+
+
+if ($flatten) {
+  $oldbody=flatten($oldbody,$oldpreamble,$oldfile,$encoding);
+  $newbody=flatten($newbody,$newpreamble,$newfile,$encoding);
+}
+
+if ( length $oldpreamble && length $newpreamble ) {
+  @oldpreamble = split /\n/, $oldpreamble;
+  @newpreamble = split /\n/, $newpreamble;
+  
+  %packages=list_packages(@newpreamble) unless %packages;
+  if (defined $packages{"hyperref"} ) {
+    print STDERR "hyperref package detected.\n" if $verbose ;
+    $latexdiffpreamble =~ s/\{\\DIFadd\}/{\\DIFaddtex}/g;
+    $latexdiffpreamble =~ s/\{\\DIFdel\}/{\\DIFdeltex}/g;
+    $latexdiffpreamble .= join "\n",(extrapream("HYPERREF"),"");
+  }
+  # insert dummy first line such that line count begins with line 1 (rather than perl's line 0) - just so that line numbers inserted by linediff are correct
+  unshift @newpreamble,'';
+  unshift @oldpreamble,'';
+  print STDERR "Differencing preamble.\n" if $verbose;
+  @diffpreamble = linediff(\@oldpreamble, \@newpreamble);
+  # remove dummy line again
+  shift @diffpreamble; 
+  push @diffpreamble,$latexdiffpreamble;
+  push @diffpreamble,'\begin{document}';
+}
+elsif ( !length $oldpreamble && !length $newpreamble ) {
+  @diffpreamble=();
+} else {
+  print STDERR "Either both texts must have preamble or neither text must have the preamble.\n";
+  exit(2);
+}
+
+if (defined $packages{"amsmath"} ) {
+  print STDERR "amsmath package detected.\n" if $verbose ;
+  $MATHARRREPL='align*';
+}
+
+print STDERR "Preprocessing body.  " if $verbose;
+my ($oldleadin,$newleadin)=preprocess($oldbody,$newbody);
+
+
+# run difference algorithm
+@diffbody=bodydiff($oldbody, $newbody);
+$diffbo=join("",@diffbody);
+print STDERR "(",exetime()," s)\n","Postprocessing body. \n " if $verbose;
+postprocess($diffbo);
+$diffall =join("\n",@diffpreamble) ;
+$diffall .= "$newleadin$diffbo" ;
+$diffall .= "\\end{document}$newpost" if length $newpreamble ;
+if ( lc($encoding) ne "utf8" && lc($encoding) ne "ascii" ) {
+  print STDERR "Encoding output file to $encoding\n" if $verbose;
+  $diffall=Encode::encode($encoding,$diffall);
+  binmode STDOUT;
+}
+print $diffall;
+
+
+print STDERR "(",exetime()," s)\n","Done.\n" if $verbose;
+
+
+
+## guess_encoding(filename)
+## reads the first 20 lines of filename and looks for call of inputenc package
+## if found, return the option of this package (encoding), otherwise return ascii
+sub guess_encoding {
+  my ($filename)=@_;
+  my ($i,$enc);
+  open (FH, $filename) or die("Couldn't open $filename: $!");
+  $i=0;
+  while (<FH>) {
+    next if /^\s*%/;    # skip comment lines
+    if (m/\\usepackage\[(\w*?)\]\{inputenc\}/) {
+      close(FH);
+      return($1);
+    }
+    last if (++$i > 20 ); # scan at most 20 non-comment lines
+  }
+  close(FH);
+  return("ascii");
+}
+
+
+sub read_file_with_encoding {
+  my ($output);
+  my ($filename, $encoding) = @_;
+
+  if (lc($encoding) eq "utf8" ) {
+    open (FILE, "<:utf8",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } elsif ( lc($encoding) eq "ascii") {
+    open (FILE, $filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+  } else {
+    require Encode;
+    open (FILE, "<",$filename) or die("Couldn't open $filename: $!");
+    local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+    $output=<FILE>;
+    print STDERR "Converting $filename from $encoding to utf8\n" if $verbose;
+    $output=Encode::decode($encoding,$output);
+  }
+  close FILE;
+  return $output;
+}
+
+# %packages=list_packages(@preamble)
+# scans the arguments for \documentclass and \usepackage statements and constructs a hash
+# whose keys are the included packages, and whose values are the associated optional arguments
+sub list_packages {
+  my (@preamble)=@_;
+  my %packages=();
+  foreach $line ( @preamble ) {
+    # get rid of comments
+    $line=~s/(?<!\\)%.*$// ;
+    if ( $line =~ m/\\(?:documentclass|usepackage)(?:\[(.+?)\])?\{(.*?)\}/ ) {
+#      print STDERR "Found something: |$line|\n";
+      if (defined($1)) {
+	$packages{$2}=$1;
+      } else {
+	$packages{$2}="";
+      }
+    }
+  }
+  return (%packages);
+}
+
+# flatten($text,$preamble,$filename,$encoding)
+# expands \input and \include commands within text
+# premable is scanned for includeonly commands
+# encoding is the encoding
+sub flatten {
+  my ($text,$preamble,$filename,$encoding)=@_;
+  my ($includeonly,$dirname,$fname,$newpage,$replacement);
+  require File::Basename ; 
+  require File::Spec ; 
+  $dirname = File::Basename::dirname($filename);
+
+  if ( ($includeonly) = ($preamble =~ m/\\includeonly{(.*?)}/ ) ) {
+    $includeonly =~ s/,/|/g;
+  } else {
+    $includeonly = '.*?';
+  }
+
+  print STDERR "DEBUG: includeonly $includeonly\n";
+
+  $text=~s/\\input{(.*?)}|\\include{(${includeonly}(?:\.tex)?)}/{ 
+	    $fname = $1 if defined($1)  ;
+	    $fname = $2 if defined($2) ;       
+            #      # add tex extension unless there is a three letter extension already 
+            $fname .= ".tex" unless $fname =~ m|\.\w{3}|;
+            print STDERR "Include file $fname\n" if $verbose;
+            print STDERR "DEBUG looking for file ",File::Spec->catfile($dirname,$fname), "\n";
+            # content of file becomes replacement value, add \newpage if the command was include
+            $replacement=read_file_with_encoding(File::Spec->catfile($dirname,$fname), $encoding) or die
+                "Couldn't find file ",File::Spec->catfile($dirname,$fname),": $!";
+	    $newpage=(defined($2)? " \\newpage " : "") ;
+	    "$newpage$replacement$newpage";
+          }/exg;
+
+  return($text);
+}
+
+
+# print_regex_arr(@arr)
+# prints regex array without x-ism expansion put in by pearl to stdout
+sub print_regex_arr {
+  my $dumstring;
+  $dumstring = join(" ",@_);     # PERL generates string (?-xism:^ref$) for quoted refex ^ref$
+  $dumstring =~ s/\(\?-xism:\^(.*?)\$\)/$1/g;   # remove string and ^,$ marks before output
+  print $dumstring,"\n";
+}
+
+
+# @lines=extrapream($type)
+# reads line from appendix (end of file after __END__ token)
+sub extrapream {
+  my $type;
+  my @retval=("%DIF PREAMBLE EXTENSION ADDED BY LATEXDIFF") ;
+  my ($copy);
+
+  while (@_) {
+    $copy=0;
+    $type=shift ;
+    if ( -f $type ) {
+      open (FILE,$type) or die "Cannot open preamble file $type: $!";
+      print STDERR "Reading preamble file $type\n" if $verbose ;
+      while (<FILE>) {
+	chomp ;
+	if ( $_ =~ m/%DIF PREAMBLE/ ) {
+	  push (@retval,"$_"); 
+	} else {
+	  push (@retval,"$_ %DIF PREAMBLE"); 
+	}
+      }
+    } 
+    else {    # not (-f $type)
+      $type=uc($type);   # upcase argument
+      print STDERR "Preamble Internal Type $type\n" if $verbose;
+      while (<DATA>) {
+	if ( m/^%DIF $type/ ) {
+	  $copy=1; }
+	elsif ( m/^%DIF END $type/ ) {
+	  last; }
+	chomp;
+	push (@retval,"$_ %DIF PREAMBLE") if $copy;
+      }
+      if ( $copy == 0 ) {
+	print STDERR "\nPreamble style $type not implemented.\n";
+        print STDERR "Write latexdiff -h to get help with available styles\n";
+        exit(2);
+      }
+      seek DATA,0,0;    # rewind DATA handle to file begin
+    }
+  }
+  push (@retval,"%DIF END PREAMBLE EXTENSION ADDED BY LATEXDIFF")  ;
+  return @retval;
+}
+
+
+# ($part1,$part2,$part3)=splitdoc($text,$word1,$word2)
+# splits $text into 3 parts at $word1 and $word2.
+# if neither $word1 nor $word2 exist, $part1 and $part3 are empty, $part2 is $text
+# If only $word1 or $word2 exist but not the other, output an error message.
+
+# NB this version avoids $` and $' for performance reason although it only makes a tiny difference
+# (in one test gain a tenth of a second for a 30s run)
+sub splitdoc {
+  my ($text,$word1,$word2)=@_;
+  my ($part1,$part2,$part3)=("","","");
+  my ($rest,$pos);
+
+  if ( $text =~ m/(^[^%]*)($word1)/mg ) {
+    $pos=pos $text;
+    $part1=substr($text,0,$pos-length($2));
+    $rest=substr($text,$pos);
+    if ( $rest =~ m/(^[^%]*)($word2)/mg ) {
+      $pos=pos $rest;
+      $part2=substr($rest,0,$pos-length($2));
+      $part3=substr($rest,$pos);
+    } 
+    else {
+      die "$word1 and $word2 not in the correct order or not present as a pair." ;
+    }
+  } else {
+    $part2=$text;
+    die "$word2 present but not $word1." if ( $text =~ m/(^[^%]*)$word2/ms );
+  }
+  return ($part1,$part2,$part3);
+}
+
+
+
+
+
+# bodydiff($old,$new)
+sub bodydiff {
+  my ($oldwords, $newwords) = @_;
+  my @retwords;
+
+  print STDERR "(",exetime()," s)\n","Splitting into latex tokens \n" if $verbose;
+  print STDERR "Parsing $oldfile \n" if $verbose;
+  my @oldwords = splitlatex($oldwords);
+  print STDERR "Parsing $newfile \n" if $verbose;
+  my @newwords = splitlatex($newwords);
+  my $token;
+
+  print STDERR "(",exetime()," s)\n","Pass 1: Expanding text commands and merging isolated identities with changed blocks  " if $verbose;
+  pass1(\@oldwords, \@newwords);
+
+
+  print STDERR "(",exetime()," s)\n","Pass 2: inserting DIF tokens and mark up.  " if $verbose;
+
+  @retwords=pass2(\@oldwords, \@newwords);
+
+  return(@retwords);
+}
+
+
+
+
+# @words=splitlatex($string)
+# split string according to latex rules
+# Each element of words is either
+# a word (including trailing spaces and punctuation)
+# a latex command
+sub splitlatex {
+  my ($string) = @_ ;
+  my @retval=($string =~ m/$pat/osg);  
+
+  if (length($string) != length(join("",@retval))) {
+    print STDERR "\nWARNING: Inconsistency in length of input string and parsed string:\n     This often indicates faulty or non-standard latex code.\n     In many cases you can ignore this and the following warning messages.\n Note that character numbers in the following are counted beginning after \\begin{document} and are only approximate." unless $ignorewarnings;
+    print STDERR "DEBUG Original length ",length($string),"  Parsed length ",length(join("",@retval)),"\n" if $debug;
+    print STDERR "DEBUG Input string:  |$string|\n" if (length($string)<500) && $debug;
+    print STDERR "DEBUG Token parsing: |",join("+",@retval),"|\n" if (length($string)<500) && $debug ;
+    @retval=();
+    # slow way only do this if other m//sg method fails
+    my $last = 0;
+    while ( $string =~ m/$pat/osg ) {
+      my $match=$&;
+      if ($last + length $& != pos $string  ) {
+	my $pos=pos($string);
+	my $offset=30<$last ? 30 : $last;
+	my $dum=substr($string,$last-$offset,$pos-$last+2*$offset);
+	my $dum1=$dum;
+	my $cnt=$#retval;
+	my $i;
+	$dum1 =~ s/\n/ /g;
+	unless ($ignorewarnings) {
+	  print STDERR "\n$dum1\n";
+	  print STDERR " " x 30,"^" x ($pos-$last)," " x 30,"\n";
+	  print STDERR "Missing characters near word " . (scalar @retval) . " character index: " . $last . "-" .  pos($string) . " Length: " . length($match) . " Match: |$match| (expected match marked above).\n";
+	}
+	  # put in missing characters `by hand'
+	push (@retval, substr($dum,$offset,$pos-$last-length($match)));
+#       Note: there seems to be a bug in substr with utf8 that made the following line output substr which were too long,
+#             using dum instead appears to work
+#	push (@retval, substr($string,$last, pos($string)-$last-length($match)));
+      }
+      push (@retval, $match);
+      $last=pos $string;
+    }
+
+  }
+  return @retval;
+}
+
+
+# pass1( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.
+# Where an common-subsequence block is flanked by deleted or appended blocks, 
+# and is shorter than $MINWORDSBLOCK words it is appended
+# to the last deleted or appended word.  If the block contains tokens other than words 
+# or punctuation it is not merged.
+# Deleted or appended block consisting of words and safe commands only are
+# also merged, to prevent break-up in pass2 (after previous isolated words have been removed)
+# If there are commands with textual arguments (e.g. \caption) both in corresponding 
+# appended and deleted blocks split them such that the command and opening bracket 
+# are one token, then the rest is split up following standard rules, and the closing 
+# bracket is a separate token, ie. turn
+# "\caption{This is a textual argument}" into 
+# ("\caption{","This ","is ","a ","textual ","argument","}")
+# No return value.  Destructively changes sequences
+sub pass1 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $len1 = scalar @$seq1;
+  my $len2 = scalar @$seq2;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;   #'
+
+  my ($last1,$last2)=(-1,-1) ;
+  my $cnt=0;
+  my $block=[];
+  my $addblock=[];
+  my $delblock=[];
+  my $todo=[];
+  my $instruction=[];
+  my $i;
+  my (@delmid,@addmid,@dummy);
+
+  my ($addcmds,$delcmds,$matchindex);
+  my ($addtextblocks,$deltextblocks);
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $adddiscard = sub {
+                      if ($cnt > 0 ) {
+			$matblkcnt++;
+			# just after an unchanged block 
+#			print STDERR "Unchanged block $cnt, $last1,$last2 \n";
+                        if ($cnt < $MINWORDSBLOCK 
+			    && $cnt==scalar (
+				     grep { /^$wpat/ || ( /^\\([\w\d\*]+)((?:\[$brat0\]|\{$pat4\})*)/o 
+							   && iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+							   && scalar(@dummy=split(" ",$2))<3 ) }
+					     @$block) )  {
+			  # merge identical blocks shorter than $MINWORDSBLOCK 
+			  # and only containing ordinary words
+			  # with preceding different word
+			  # We cannot carry out this merging immediately as this
+			  # would change the index numbers of seq1 and seq2 and confuse
+			  # the algorithm, instead we store in @$todo where we have to merge
+                          push(@$todo, [ $last1,$last2,$cnt,@$block ]);
+			}
+			$block = []; 
+			$cnt=0; $last1=-1; $last2=-1;
+		      }
+		    };
+  my $discard=sub { $deltokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$delblock,[ $seq1->[$_[0]],$_[0] ]);
+		    $last1=$_[0] };		      
+
+  my $add =   sub { $addtokcnt++;
+                    &$adddiscard; #($_[0],$_[1]);
+		    push(@$addblock,[ $seq2->[$_[1]],$_[1] ]);
+		    $last2=$_[1] };		      
+
+  my $match = sub { $mattokcnt++;
+                    if ($cnt==0) {   # first word of matching sequence after changed sequence or at beginning of word sequence
+		      $deltextblocks = extracttextblocks($delblock); 
+		      $delblkcnt++ if scalar @$delblock;
+		      $addtextblocks = extracttextblocks($addblock);
+		      $addblkcnt++ if scalar @$addblock;
+
+		      $delcmds = extractcommands($delblock);
+      		      $addcmds = extractcommands($addblock);
+		      # keygen(third argument of _longestCommonSubsequence) implies to sort on command (0th elements of $addcmd elements)
+		      # the calling format for longestCommonSubsequence has changed between versions of
+		      # Algorithm::Diff so we need to check which one we are using
+		      if ( $algodiffversion  > 1.15 ) {
+			### Algorithm::Diff 1.19
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, 0, sub { $_[0]->[0] } );
+		      } else {
+			### Algorithm::Diff 1.15	
+			$matchindex=Algorithm::Diff::_longestCommonSubsequence($delcmds,$addcmds, sub { $_[0]->[0] } );
+		      }
+
+		      for ($i=0 ; $i<=$#$matchindex ; $i++) {
+			if (defined($matchindex->[$i])){
+			  $j=$matchindex->[$i];
+			  @delmid=splitlatex($delcmds->[$i][3]);
+			  @addmid=splitlatex($addcmds->[$j][3]);
+			  while (scalar(@$deltextblocks)  && $deltextblocks->[0][0]<$delcmds->[$i][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$deltextblocks) };
+			    push(@$todo, [$index,-1,$cnt,@$block]);
+			  }
+			  push(@$todo, [ $delcmds->[$i][1],-1,-1,$delcmds->[$i][2],@delmid,$delcmds->[$i][4]]);
+
+			  while (scalar(@$addtextblocks) && $addtextblocks->[0][0]<$addcmds->[$j][1]) {
+			    my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			    push(@$todo, [-1,$index,$cnt,@$block]);
+			  }
+			  push(@$todo, [ -1,$addcmds->[$j][1],-1,$addcmds->[$j][2],@addmid,$addcmds->[$j][4]]);
+			}
+		      }
+		      # mop up remaining textblocks
+		      while (scalar(@$deltextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$deltextblocks) } ;
+			push(@$todo, [$index,-1,$cnt,@$block]);
+		      }
+		      while (scalar(@$addtextblocks)) {
+			my ($index,$block,$cnt)=@{ shift(@$addtextblocks) };
+			push(@$todo, [-1,$index,$cnt,@$block]);
+		      }
+		      
+		      $addblock=[];
+		      $delblock=[];
+		    }
+		    push(@$block,$seq2->[$_[1]]);  
+		    $cnt++  };
+
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+
+
+  # now carry out the merging/splitting.  Refer to elements relative from 
+  # the end (with negative indices) as these offsets don't change before the instruction is executed
+  # cnt>0: merged small unchanged groups with previous changed blocks
+  # cnt==-1: split textual commands into components
+  foreach $instruction ( @$todo) {
+    ($last1,$last2,$cnt,@$block)=@$instruction ;
+    if ($cnt>=0) {
+      splice(@$seq1,$last1-$len1,1+$cnt,join("",$seq1->[$last1-$len1],@$block)) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1+$cnt,join("",$seq2->[$last2-$len2],@$block)) if $last2>=0;
+    } else {
+      splice(@$seq1,$last1-$len1,1,@$block) if $last1>=0;
+      splice(@$seq2,$last2-$len2,1,@$block) if $last2>=0;
+    }
+  }
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens in $matblkcnt blocks.\n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+}
+
+
+# extracttextblocks(\@blockindex)
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [[ $index, $textblock, $cnt ], ..
+# where $index index of block to be merged
+#       $textblock contains all the words to be merged with the word at $index (but does not contain this word)
+#       $cnt   is length of block
+#
+# requires: iscmd
+#
+sub extracttextblocks { 
+  my $block=shift;
+  my ($i,$token,$index);
+  my $textblock=[];
+  my $last=-1;
+  my $wpat=qr/^(?:[a-zA-Z.,'`:;?()!]*)[\s~]*$/;  #'
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # store pure text blocks
+    if ($token =~ /$wpat/ ||  ( $token =~/^\\([\w\d\*]+)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*)/o 
+				&& iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL) 
+				&& !iscmd($1,\@TEXTCMDLIST,\@TEXTCMDEXCL))) {
+      # we have text or a command which can be treated as text
+      if ($last<0) {
+	# new pure-text block
+	$last=$index;
+      } else {
+	# add to pure-text block
+	push(@$textblock, $token); 
+      }
+    } else {
+      # it is not text
+      if (scalar(@$textblock)) {
+	push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+      }
+      $textblock=[];
+      $last=-1;
+    }
+  }
+  # finish processing a possibly unfinished block before returning
+  if (scalar(@$textblock)) {
+    push(@$retval,[ $last, $textblock, scalar(@$textblock) ]);
+  }
+  return($retval)
+}
+
+
+
+# extractcommands( \@blockindex )
+# $blockindex has the following format 
+# [ [ token1, index1 ], [token2, index2],.. ] 
+# where index refers to the index in the original old or new word sequence 
+# Returns: reference to an array of the form  
+# [ [ "\cmd1", index, "\cmd1[optarg]{arg1}{", "arg2" ,"} " ],.. 
+# where index is just taken from input array 
+# command must have a textual argument as last argument 
+# 
+# requires: iscmd 
+# 
+sub extractcommands { 
+  my $block=shift;
+  my ($i,$token,$index,$cmd,$open,$mid,$closing);
+  my $retval=[];
+
+  for ($i=0;$i< scalar @$block;$i++) {
+    ($token,$index)=@{ $block->[$i] };
+    # check if token is an alphanumeric command sequence with at least one non-optional argument
+    # \cmd[...]{...}{last argument}  
+    # Capturing in the following results in these associations
+    # $1: \cmd[...]{...}{
+    # $2: \cmd
+    # $3: last argument
+    # $4: }  + trailing spaces
+    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	 && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL) ) {
+      #      push(@$retval,[ $2,$index,$1,$3,$4 ]);
+      ($cmd,$open,$mid,$closing) = ($2,$1,$3,$4) ;
+      $closing =~ s/\}/\\RIGHTBRACE/ ;
+      push(@$retval,[ $cmd,$index,$open,$mid,$closing ]);
+    }
+  }
+  return $retval;
+}
+
+# iscmd($cmd,\@regexarray,\@regexexcl) checks
+# return 1 if $cmd matches any of the patterns in the 
+# array $@regexarray, and none of the patterns in \@regexexcl, otherwise return 0
+sub iscmd {
+  my ($cmd,$regexar,$regexexcl)=@_;
+  my ($ret)=0;
+  foreach $pat ( @$regexar ) {
+    if ( $cmd =~ m/^${pat}$/ ) {
+      $ret=1 ; 
+      last;
+    }
+  }
+  return 0 unless $ret;
+  foreach $pat ( @$regexexcl ) {
+    return 0 if ( $cmd =~ m/^${pat}$/ );
+  }
+  return 1;
+}
+
+
+# pass2( \@seq1,\@seq2)
+# Look for differences between seq1 and seq2.  
+# Mark begin and end of deleted and appended sequences with tags $DELOPEN and $DELCLOSE
+# and $ADDOPEN and $ADDCLOSE, respectively, however exclude { } & and all comands, unless
+# they match an element of the whitelist (SAFECMD)
+# For words in TEXTCMD but not in SAFECMD, enclose interior with $ADDOPEN and $ADDCLOSE brackets
+# Deleted comment lines are marked with %DIF < 
+# Added comment lines are marked with %DIF > 
+sub pass2 {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my ($addtokcnt,$deltokcnt,$mattokcnt)=(0,0,0);
+  my ($addblkcnt,$delblkcnt,$matblkcnt)=(0,0,0);
+
+  my $retval = [];
+  my $delhunk   = [];
+  my $addhunk   = [];
+
+  my $discard = sub { $deltokcnt++;
+                      push ( @$delhunk, $seq1->[$_[0]]) };
+
+  my $add = sub { $addtokcnt++;
+                  push ( @$addhunk, $seq2->[$_[1]]) };
+
+  my $match = sub { $mattokcnt++;
+		    if ( scalar @$delhunk ) {
+                      $delblkcnt++;
+		      # mark up changes, but comment out commands
+                      push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk);
+		      $delhunk = [];
+		    }
+                    if ( scalar @$addhunk ) {
+                      $addblkcnt++;
+                      # we mark up changes, but simply quote commands
+                      push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk);
+		      $addhunk = [];
+		    }
+		    push(@$retval,$seq2->[$_[1]]) };
+ 
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  # clear up unprocessed hunks
+  push @$retval,marktags($DELMARKOPEN,$DELMARKCLOSE,$DELOPEN,$DELCLOSE,$DELCMDOPEN,$DELCMDCLOSE,$DELCOMMENT,$delhunk) if scalar @$delhunk;
+  push @$retval,marktags($ADDMARKOPEN,$ADDMARKCLOSE,$ADDOPEN,$ADDCLOSE,"","",$ADDCOMMENT,$addhunk) if scalar @$addhunk;
+
+
+  if ($verbose) { 
+    print STDERR "\n";
+    print STDERR "  $mattokcnt matching  tokens. \n";
+    print STDERR "  $deltokcnt discarded tokens in $delblkcnt blocks.\n";
+    print STDERR "  $addtokcnt appended  tokens in $addblkcnt blocks.\n";
+  }
+
+  return(@$retval);
+}
+
+# marktags($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,\@block)
+# returns ($openmark,$open,$block,$close,$closemark) if @block only contains no commands (except white-listed ones),
+# braces, ampersands, or comments
+# mark comments with $comment
+# exclude all other exceptions from scope of open, close like this
+# ($openmark, $open,...,$close, $opencomd,command, command,$closecmd, $open, ..., $close, $closemark)
+# If $opencmd begins with "%" marktags assumes it is operating on a deleted block, otherwise on an added block
+sub marktags {
+  my ($openmark,$closemark,$open,$close,$opencmd,$closecmd,$comment,$block)=@_;
+  my $word;
+  my (@argtext);
+  my $retval=[];
+  my $noncomment=0;
+  my $cmd=-1;    # -1 at beginning 0: last token written is a ordinary word 
+                 # 1: last token written is a command
+                # for keeping track whether we are just in a command sequence or in a word sequence
+  my $cmdcomment= ($opencmd =~ m/^%/);  # Flag to indicate whether opencmd is a comment (i.e. if we intend to simply comment out changed commands)
+  my ($command,$commandword,$closingbracket) ; # temporary variables needed below to remember sub-pattern matches
+
+# split this block to flatten out sequences joined in pass1
+  @$block=splitlatex(join "",@$block);
+  foreach (@$block) {
+    $word=$_; 
+    if ( $word =~ s/^%/%$comment/ ) {
+      # a comment
+      if ($cmd==1) {
+	push (@$retval,$closecmd) ;
+	$cmd=-1;
+      }
+      push (@$retval,$word); 
+      next;
+    }
+    if (! $noncomment) {
+      push (@$retval,$openmark); 
+      $noncomment=1;
+    }
+    # negative lookahead pattern (?!) in second clause is put in to avoid mathcing \( .. \) patterns
+    if ( $word =~ /^[&{}\[\]]/ || ( $word =~ /^\\(?!\()([\w*@]*)/ && !iscmd($1,\@SAFECMDLIST,\@SAFECMDEXCL)) ) {
+      # word is a command or other significant token (not in SAFECMDLIST)
+	## same conditions as in subroutine extractcommand:
+	# check if token is an alphanumeric command sequence with at least one non-optional argument
+	# \cmd[...]{...}{last argument}  
+	# Capturing in the following results in these associations
+	# $1: \cmd[...]{...}{
+	# $2: \cmd
+	# $3: last argument
+	# $4: }  + trailing spaces
+	### pre-0.3    if ( ( $token =~ m/^(\\([\w\d\*]+)(?:\[$brat0\]|\{$pat4\})*\{)($pat4)(\}\s*)$/so )
+      if ( ( $word =~ m/^(\\([\w\d\*]+)(?:${extraspace}\[$brat0\]|${extraspace}\{$pat4\})*${extraspace}\{)($pat4)(\}\s*)$/so )
+	   && iscmd($2,\@TEXTCMDLIST,\@TEXTCMDEXCL)  && ( !$cmdcomment || !iscmd($2,\@CONTEXT2CMDLIST, \@CONTEXT2CMDEXCL) )  ) {	 
+	# word is a text command - we mark up the interior of the word. But if we are in a deleted block ($cmdcomment=1) and
+        # $2 (the command) is in context2, just treat it as an ordinary command (i.e. comment it open with $opencmd)
+        # Because we do not want to disable this command
+	# here we do not use $opencmd and $closecmd($opencmd is empty) 
+	if ($cmd==1) {
+	  push (@$retval,$closecmd) ;
+	} elsif ($cmd==0) { 
+	  push (@$retval,$close) ;
+	}
+        $command=$1; $commandword=$2; $closingbracket=$4;
+	@argtext=splitlatex($3);   # split textual argument into tokens
+	# and mark it up (but we do not need openmark and closemark)
+        # insert command with initial arguments, marked-up final argument, and closing bracket
+	if ( $cmdcomment && iscmd($commandword,\@CONTEXT1CMDLIST, \@CONTEXT1CMDEXCL) ) {
+	  # context1cmd in a deleted environment; delete command itself but keep last argument, marked up
+	  push (@$retval,$opencmd);
+	  $command =~ s/\n/\n${opencmd}/sg ; # repeat opencmd at the beginning of each line
+	  # argument, note that the additional comment character is included
+          # to suppress linebreak after opening parentheses, which is important
+          # for latexrevise
+          push (@$retval,$command,"%\n{$AUXCMD\n",marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);
+	} else {
+	  # normal textcmd or context1cmd in an added block
+	  push (@$retval,$command,marktags("","",$open,$close,$opencmd,$closecmd,$comment,\@argtext),$closingbracket);  
+	}
+	push (@$retval,$AUXCMD,"\n") if $cmdcomment ;
+	$cmd=-1 ;
+      } else {
+	# ordinary command
+	push (@$retval,$opencmd) if $cmd==-1 ;
+	push (@$retval,$close,$opencmd) if $cmd==0 ;
+	$word =~ s/\n/\n${opencmd}/sg if $cmdcomment ;   # if opencmd is a comment, repeat this at the beginning of every line
+	push (@$retval,$word);
+	$cmd=1;
+      }
+    } else {
+      # just an ordinary word or word in SAFECMD
+      push (@$retval,$open) if $cmd==-1 ;
+      push (@$retval,$closecmd,$open) if $cmd==1 ;
+      push (@$retval,$word);
+      $cmd=0;
+    }
+  }
+  push (@$retval,$close) if $cmd==0;
+  push (@$retval,$closecmd) if $cmd==1;
+
+  push (@$retval,$closemark) if ($noncomment);
+  return @$retval;
+}
+
+# preprocess($string, ..)
+# carry out the following pre-processing steps for all arguments:
+# 1. Remove leading white-space
+# 2. mark all first empty line (in block of several) with \PAR tokens
+# 3. Convert all '\%' into '\PERCENTAGE ' to make parsing regular expressions easier
+# 4. Convert all \verb|some verbatim text| commands (where | can be an arbitrary character)
+#    into \verb{hash}
+# 5. Convert \begin{verbatim} some verbatim text \end{verbatim} into \verbatim{hash}
+# 6. Convert _n into \SUBSCRIPTNB{n} and _{nnn} into \SUBSCRIPT{nn}
+# 7. Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+# 8. a. Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+#    b. Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+
+# 9. Add final token STOP to the very end.  This is put in because the algorithm works better if the last token is identical.  This is removed again in postprocessing.
+#
+# NB: step 6 and 7 is likely to  convert some "_" inappropriately, e.g. in file
+#     names or labels but it does not matter because they are converted back in the postprocessing step
+# Returns: leading white space removed in step 1
+sub preprocess {
+  my @leadin=() ;
+  for (@_) { 
+    s/^(\s*)//s;
+    push(@leadin,$1);
+    s/\n(\s*?)\n((?:\s*\n)*)/\n$1\\PAR\n$2/g ;
+    s/(?<!\\)\\%/\\PERCENTAGE /g ;  # (?<! is negative lookbehind assertion to prevent \\% from being converted
+    s/(\\verb\*?)(\S)(.*?)\2/"${1}{". tohash(\%verbhash,"${2}${3}${2}") ."}"/esg;
+    s/\\begin\{(verbatim\*?)\}(.*?)\\end\{\1\}/"\\${1}{". tohash(\%verbhash,"${2}") . "}"/esg;
+    # Convert _n or _\cmd into \SUBSCRIPTNB{n} or \SUBSCRIPTNB{\cmd} and _{nnn} into \SUBSCRIPT{nn}
+    s/_([^{\\]|\\\w+)/\\SUBSCRIPTNB{$1}/g ;
+    s/_{($pat4)}/\\SUBSCRIPT{$1}/g ;
+    # Convert ^n into \SUPERSCRIPTNB{n} and ^{nnn} into \SUPERSCRIPT{nn}
+    s/\^([^{\\]|\\\w+)/\\SUPERSCRIPTNB{$1}/g ;
+    s/\^{($pat4)}/\\SUPERSCRIPT{$1}/g ;
+    # Convert $$ $$ into \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR}
+    s/\$\$(.*?)\$\$/\\begin{DOLLARDOLLAR}$1\\end{DOLLARDOLLAR}/sg;
+    # Convert \[ \] into \begin{SQUAREBRACKET} \end{SQUAREBRACKET}
+    s/(?<!\\)\\\[/\\begin{SQUAREBRACKET}/sg;
+    s/\\\]/\\end{SQUAREBRACKET}/sg;
+    # add final token " STOP"
+    $_ .= " STOP"
+  }
+  return(@leadin);
+}
+
+#hashstring=tohash(\%hash,$string)
+# creates a hash value based on string and stores in %hash
+sub tohash {
+  my ($hash,$string)=@_;
+  my (@arr,$val);
+  my ($sum,$i)=(0,1);
+  my ($hstr);
+
+  @arr=unpack('c*',$string);
+
+  foreach $val (@arr) {
+    $sum += $i*$val;
+    $i++;
+  }
+  $hstr= "$sum";
+  if (defined($hash->{$hstr}) && $string ne $hash->{$hstr}) {
+    warn "Repeated hash value for verbatim mode in spite of different content.";
+    $hstr="-$hstr";
+  }
+  $hash->{$hstr}=$string;
+  return($hstr);
+}
+
+#string=fromhash(\%hash,$fromstring)
+# restores string value stored in hash
+#string=fromhash(\%hash,$fromstring,$prependstring)
+# additionally begins each line with prependstring
+sub fromhash {
+  my ($hash,$hstr)=($_[0],$_[1]);
+  my $retstr=$hash->{$hstr};
+  if ( $#_ >= 2) {
+    $retstr =~ s/^/$_[2]/mg;
+  }
+  return $retstr;
+}
+
+
+# postprocess($string, ..)
+# carry out the following post-processing steps for all arguments:
+# * Remove STOP token from the end
+# * Replace \RIGHTBRACE by }
+# 1. Check all deleted blocks: 
+#    a.where a deleted block contains a matching \begin and
+#      \end environment (these will be disabled by a %DIFDELCMD statements), for selected environment enable enable
+#      these commands again (such that for example displayed math in a deleted equation
+#      is properly within math mode.  For math mode environments replace numbered equation
+#      environments with their display only variety (so that equation numbers in new file and
+#      diff file are identical).  Where the correct type of math environment cannot be determined
+#      use a place holder MATHMODE
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+#    Replace all MATHMODE environment commands by the correct environment to achieve matching
+#    pairs
+#    c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+# 2. Remove DIFadd, DIFdel, DIFFaddbegin , ... from picture environments
+# 3. Convert DIFadd, DIFdel, DIFFaddbegin , ... into FL varieties
+#    within floats (currently recognised float environments: plate,table,figure
+#    plus starred varieties).
+# 4. Remove empty %DIFDELCMD < lines 
+# 4. Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+#    Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+# 6. Convert  \SUBSCRIPTNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+# 7. Expand hashes of verb and verbatim environments
+# 8. Convert '\PERCENTAGE ' back into '\%'
+# 9.. remove all \PAR tokens
+# 10.  package specific processing:  endfloat: make sure \begin{figure} and \end{figure} are always
+#      on a line by themselves, similarly for table environment
+#  4, undo renaming of the \begin and \end in comments
+
+#
+# Note have to manually synchronize substitution commands below and 
+# DIF.. command names in the header
+sub postprocess {
+  my ($begin,$len,$cnt,$float,$delblock,$addblock);
+  # second level blocks
+  my ($begin2,$cnt2,$len2,$eqarrayblock,$mathblock);
+
+  for (@_) { 
+
+    # change $'s in comments to something harmless
+    1 while s/(%.*)\$/$1DOLLARDIF/mg ;
+
+    # Remove final STOP token
+    s/ STOP$//;
+    # Replace \RIGHTBRACE by }    
+    s/\\RIGHTBRACE/}/g;
+    # Check all deleted blocks: where a deleted block contains a matching \begin and
+    #    \end environment (these will be disabled by a %DIFDELCMD statements), enable
+    #    these commands again (such that for example displayed math in a deleted equation
+    #    is properly within math mode.  For math mode environments replace numbered equation
+    #    environments with their display only variety (so that equation numbers in new file and
+    #    diff file are identical
+    while ( m/\\DIFdelbegin.*?\\DIFdelend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $delblock=$&;
+
+
+      ### (.*?[^\n]?)\n? construct is necessary to avoid empty lines in math mode, which result in
+      ### an error
+      # displayed math environments
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHREPL}$AUXCMD\n$1$3\n\\end{$MATHREPL}$AUXCMD\n$4/sg;
+      # also transform the opposite pair \end{displaymath} .. \begin{displaymath} but we have to be careful not to interfere with the results of the transformation in the line directly above
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHENV}; if found add \begin{$MATHREPL} and insert \end{$MATHREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{((?:$MATHENV)|SQUAREBRACKET)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+
+      # equation array environment
+      $delblock=~ s/(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(\%DIFDELCMD < \s*\\end\{\2\})/\\begin{$MATHARRREPL}$AUXCMD\n$1$3\n\\end{$MATHARRREPL}$AUXCMD\n$4/sg;
+      $delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))(.*?[^\n]?)\n?(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{\2\})/\\end{MATHMODE}$AUXCMD\n$1$3\n\\begin{MATHMODE}$AUXCMD\n$4/sg;
+
+      # now look for unpaired %DIFDELCMD < \begin{MATHARRENV}; if found add \begin{$MATHARRREPL} and insert \end{$MATHARRREPL} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\begin\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\begin{$MATHARRREPL}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\end{$MATHARRREPL}$AUXCMD\n$1/s ;
+      }
+      # now look for unpaired %DIFDELCMD < \end{MATHENV}; if found add \end{MATHMODE} and insert \begin{MATHMODE} 
+      # just before end of block; again we use look-behind assertion to avoid matching constructions which have already been converted
+      if ($delblock=~ s/(?<!${AUXCMD}\n)(\%DIFDELCMD < \s*\\end\{($MATHARRENV)\}\s*?(?:$DELCMDCLOSE|\n))/$1\\end{MATHMODE}$AUXCMD\n/sg ) {
+	$delblock =~ s/(\\DIFdelend$)/\\begin{MATHMODE}$AUXCMD\n$1/s ;
+      }
+
+      # parse $delblock for deleted and reinstated eqnarray* environments - within those reinstate \\ and & commands
+      while ( $delblock =~ m/\\begin\Q{$MATHARRREPL}$AUXCMD\E\n.*?\n\\end\Q{$MATHARRREPL}$AUXCMD\E\n/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$eqarrayblock=$&;
+	# reinstate deleted & and \\ commands
+	$eqarrayblock=~ s/(\%DIFDELCMD < \s*(\&|\\\\)\s*?(?:$DELCMDCLOSE|\n))/$1$2$AUXCMD\n/sg ;
+
+	substr($delblock,$begin2,$len2)=$eqarrayblock;
+	pos($delblock) = $begin2 + length($eqarrayblock);
+      }
+
+
+
+#    b.where one of the commands matching $COUNTERCMD is used as a DIFAUXCMD, add a statement
+#      subtracting one from the respective counter to keep numbering consistent with new file
+      $delblock=~ s/\\($COUNTERCMD)((?:${extraspace}\[$brat0\]${extraspace}|${extraspace}\{$pat4\})*\s*${AUXCMD}\n)/\\$1$2\\addtocounter{$1}{-1}${AUXCMD}\n/sg ;
+#     c. If in-line math mode contains array environment, enclose the whole environment in \mbox'es
+      while ( $delblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($delblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($delblock,$begin2,$len2)=$mathblock;
+	pos($delblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified delblock
+      substr($_,$begin,$len)=$delblock;
+      pos = $begin + length($delblock);
+    }
+    # make the array modification in added blocks
+    while ( m/\\DIFaddbegin.*?\\DIFaddend/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $addblock=$&;
+      while ( $addblock =~ m/($math)(\s*)/sg ) {
+	$cnt2=0;
+	$len2=length($&);
+	$begin2=pos($addblock) - $len2;
+	$mathblock="%\n\\mbox{$AUXCMD\n$1\n}$AUXCMD\n";
+        next unless $mathblock =~ m/\{$ARRENV\}/ ;
+	substr($addblock,$begin2,$len2)=$mathblock;
+	pos($addblock) = $begin2 + length($mathblock);
+      }
+
+#     splice in modified addblock
+      substr($_,$begin,$len)=$addblock;
+      pos = $begin + length($addblock);
+    }
+
+
+    ### old place for BEGINDIF, ENDDIF replacement
+    # change begin and end commands  within comments such that they
+    # don't disturb the pattern matching (if there are several \begin or \end in one line
+    # this substitution is insufficient but that appears unlikely)
+    s/(%.*)\\begin\{(.*)$/$1\\BEGINDIF\{$2/mg ;
+    s/(%.*)\\end\{(.*)$/$1\\ENDDIF\{$2/mg ;
+
+    # Replace MATHMODE environments from step 1a above by the correct Math environment
+
+    # The next line is complicated.  The negative look-ahead insertion makes sure that no \end{$MATHENV} (or other mathematical
+    # environments) are between the \begin{$MATHENV} and \end{MATHMODE} commands. This is necessary as the minimal matching 
+    # is not globally minimal but only 'locally' (matching is beginning from the left side of the string)
+    1 while s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}((?:.(?!(?:\\end{(?:(?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}|\\begin{MATHMODE})))*?)\\end{MATHMODE}/\\begin{$1}$2\\end{$1}/s;
+    1 while s/\\begin{MATHMODE}((?:.(?!\\end{MATHMODE}))*?)\\end{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}/\\begin{$2}$1\\end{$2}/s;
+    # convert remaining \begin{MATHMODE} \end{MATHMODE} (and not containing & or \\ )into MATHREPL environments
+    s/\\begin{MATHMODE}((?:(.(?!(?<!\\)\&|\\\\))*)?)\\end{MATHMODE}/\\begin{$MATHREPL}$1\\end{$MATHREPL}/sg;
+    # others into MATHARRREPL
+    s/\\begin{MATHMODE}(.*?)\\end{MATHMODE}/\\begin{$MATHARRREPL}$1\\end{$MATHARRREPL}/sg;
+
+    # now look for AUXCMD math-mode pairs which have only comments (or empty lines between them), and remove the added commands
+    s/\\begin{((?:$MATHENV)|(?:$MATHARRENV)|SQUAREBRACKET)}$AUXCMD\n((?:\s*%.[^\n]*\n)*)\\end{\1}$AUXCMD\n/$2/sg; 
+
+
+    # Remove all mark up within picture environments
+    while ( m/\\begin\{($PICTUREENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin //g;
+      $float =~ s/\\DIFaddend //g;
+      $float =~ s/\\DIFadd\{($pat4)\}/$1/g;
+      $float =~ s/\\DIFdelbegin //g;
+      $float =~ s/\\DIFdelend //g;
+      $float =~ s/\\DIFdel\{($pat4)\}//g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    # Convert DIFadd, DIFdel, DIFFaddbegin , ... into  varieties
+    #    within floats (currently recognised float environments: plate,table,figure
+    #    plus starred varieties).
+    while ( m/\\begin\{($FLOATENV)\}.*?\\end\{\1\}/sg ) {
+      $cnt=0;
+      $len=length($&);
+      $begin=pos($_) - $len;
+      $float=$&;
+      $float =~ s/\\DIFaddbegin /\\DIFaddbeginFL /g;
+      $float =~ s/\\DIFaddend /\\DIFaddendFL /g;
+      $float =~ s/\\DIFadd\{/\\DIFaddFL{/g;
+      $float =~ s/\\DIFdelbegin /\\DIFdelbeginFL /g;
+      $float =~ s/\\DIFdelend /\\DIFdelendFL /g;
+      $float =~ s/\\DIFdel\{/\\DIFdelFL{/g;
+      substr($_,$begin,$len)=$float;
+      pos = $begin + length($float);
+    }
+    ### former location of undo renaming of \begin and \end in comments
+
+    # remove empty DIFCMD < lines
+    s/^\Q${DELCMDOPEN}\E\n//msg;
+
+    # Expand hashes of verb and verbatim environments (note negative look behind assertion to not leak out of DIFDELCMD comments
+    s/(\\verb\*?)\{([-\d]*?)\}/"${1}". fromhash(\%verbhash,$2)/esg;
+    s/${DELCMDOPEN}\\(verbatim\*?)\{([-\d]*?)\}/"${DELCMDOPEN}\\begin{${1}}".fromhash(\%verbhash,$2,$DELCMDOPEN)."${DELCMDOPEN}\\end{${1}}"/esg;
+    s/\\(verbatim\*?)\{([-\d]*?)\}/"\\begin{${1}}".fromhash(\%verbhash,$2)."\\end{${1}}"/esg;
+    # Convert '\PERCENTAGE ' back into '\%'			       
+    s/\\PERCENTAGE /\\%/g;
+    # remove all \PAR tokens (taking care to properly keep commented out PAR's
+    # from introducing uncommented newlines - next line)
+    s/(%DIF < )([^\n]*?)\\PAR\n/$1$2\n$1\n/sg;
+    # convert PAR commands which are on a line by themselves
+    s/\n(\s*?)\\PAR\n/\n\n/sg;
+    # convert remaining PAR commands (which are preceded by non-white space characters, usually "}" ($ADDCLOSE)
+    s/\\PAR\n/\n\n/sg;
+
+    #  package specific processing: 
+    if ( defined($packages{"endfloat"})) {
+      #endfloat: make sure \begin{figure} and \end{figure} are always
+      #      on a line by themselves, similarly for table environment
+      print STDERR "endfloat package detected.\n" if $verbose ;
+      # eliminate whitespace before and after
+      s/^(\s*)(\\(?:begin|end)\{(?:figure|table)\})(\s*)$/$2/mg;
+      # split lines with remaining characters before float enviroment conmmand
+      s/^(.+)(\\(?:begin|end)\{(?:figure|table)\})/$1\n$2/mg;
+      # split lines with remaining characters after float enviroment conmmand
+      s/(\\(?:begin|end)\{(?:figure|table)\})(.+)$/$1\n$2/mg;
+    }
+    # undo renaming of the \begin and \end  and dollars in comments 
+    s/(%.*)\\BEGINDIF\{(.*)$/$1\\begin\{$2/mg ;
+    s/(%.*)\\ENDDIF\{(.*)$/$1\\end\{$2/mg ;
+    1 while s/(%.*)DOLLARDIF/$1\$/mg ;
+#   Convert \begin{SQUAREBRACKET} \end{SQUAREBRACKET} into \[ \]
+    s/\\end{SQUAREBRACKET}/\\\]/sg;
+    s/\\begin{SQUAREBRACKET}/\\\[/sg;
+# 4. Convert \begin{DOLLARDOLLAR} \end{DOLLARDOLLAR} into $$ $$
+    s/\\begin\{DOLLARDOLLAR\}(.*?)\\end\{DOLLARDOLLAR\}/\$\$$1\$\$/sg;
+# 5. Convert  \SUPERSCRIPTNB{n} into ^n  and  \SUPERSCRIPT{nn} into ^{nnn}
+    s/\\SUPERSCRIPTNB{($pat0)}/^$1/g ;
+    s/\\SUPERSCRIPT{($pat4)}/^{$1}/g ;
+    # Convert  \SUBSCRIPNB{n} into _n  and  \SUBCRIPT{nn} into _{nnn}
+    s/\\SUBSCRIPTNB{($pat0)}/_$1/g ;
+    s/\\SUBSCRIPT{($pat4)}/_{$1}/g ;
+
+  return;
+  }
+}
+
+
+# @diffs=linediff(\@seq1, \@seq2)
+# mark up lines like this
+#%DIF mm-mmdnn
+#%< old deleted line(s)
+#%DIF -------
+#%DIF mmann-nn
+#new appended line %< 
+#%DIF -------
+# Future extension: mark change explicitly
+# Assumes: traverse_sequence traverses deletions before insertions in changed sequences
+#          all line numbers relative to line 0 (first line of real file)
+sub linediff {
+  my $seq1 = shift ;
+  my $seq2 = shift ;
+
+  my $block = [];
+  my $retseq = [];
+  my @begin=('','',''); # dummy initialisation
+  my $instring ; 
+
+  my $discard = sub { @begin=('d',$_[0],$_[1]) unless scalar @$block ; 
+                      push(@$block, "%DIF < " . $seq1->[$_[0]]) };
+  my $add = sub { if (! scalar  @$block) {
+		    @begin=('a',$_[0],$_[1]) ;}
+		  elsif ( $begin[0] eq 'd' ) {
+                    $begin[0]='c'; $begin[2]=$_[1];
+		    push(@$block, "%DIF -------") }
+                  push(@$block,  $seq2->[$_[1]] . " %DIF > " ) };
+  my $match = sub { if ( scalar @$block ) {
+                      if ( $begin[0] eq 'd' && $begin[1]!=$_[0]-1) {
+			$instring = sprintf "%%DIF %d-%dd%d",$begin[1],$_[0]-1,$begin[2]; }
+		      elsif ( $begin[0] eq 'a' && $begin[2]!=$_[1]-1) {
+			$instring = sprintf "%%DIF %da%d-%d",$begin[1],$begin[2],$_[1]-1; }
+		      elsif ( $begin[0] eq 'c' ) {
+			$instring = sprintf "%%DIF %sc%s",
+			                     ($begin[1]==$_[0]-1) ? "$begin[1]" : $begin[1]."-".($_[0]-1)  , 
+			                     ($begin[2]==$_[1]-1) ? "$begin[2]" : $begin[2]."-".($_[1]-1)  ; }
+		      else {
+			$instring = sprintf "%%DIF %d%s%d",$begin[1],$begin[0],$begin[2]; }
+		      push @$retseq, $instring,@$block, "%DIF -------" ; 
+		      $block = []; 
+		    }
+		    push @$retseq, $seq2->[$_[1]]
+		  };
+  # key function: remove multiple spaces (such that insertion or deletion of redundant white space is not reported)
+  my $keyfunc = sub { join("  ",split(" ",shift())) };
+
+  traverse_sequences($seq1,$seq2, { MATCH=>$match, DISCARD_A=>$discard, DISCARD_B=>$add }, $keyfunc );
+  push @$retseq, @$block if scalar @$block; 
+
+  return wantarray ? @$retseq : $retseq ;
+}
+
+
+
+# init_regex_arr_data(\@array,"TOKEN INIT")
+# scans DATA file handel for line "%% TOKEN INIT" line
+# then appends each line not beginning with % into array (as a quoted regex)
+sub init_regex_arr_data {
+  my ($arr,$token)=@_;
+  my ($copy);
+  while (<DATA>) {
+    if ( m/^%%BEGIN $token\s*$/ ) {
+      $copy=1; }
+    elsif ( m/^%%END $token\s*/ )  {
+      last; }
+    chomp;
+    push (@$arr,qr/^$_$/) if ( $copy && !/^%/ ) ;
+  }
+  seek DATA,0,0;    # rewind DATA handle to file begin
+}
+
+
+# init_regex_arr_ext(\@array,$arg)
+# fills array with regular expressions.
+# if arg is a file name, then read in list of regular expressions from that file
+# (one expression per line)
+# Otherwise treat arg as a comma separated list of regular expressions
+sub init_regex_arr_ext {
+  my ($arr,$arg)=@_;
+  my $regex;
+  if ( -f $ arg ) {
+    open(FILE,"$arg") or die ("Couldn't open $arg: $!");
+    while (<FILE>) {
+      chomp;
+      next if /^\s*#/ || /^\s*%/ || /^\s*$/ ;
+      push (@$arr,qr/^$_$/);
+    }
+    close(FILE);
+  }
+  else {
+    # assume it is a comma-separated list of reg-ex
+    foreach $regex (split(qr/(?<!\\),/,$arg)) {
+      $regex =~ s/\\,/,/g;
+      push (@$arr,qr/^$regex$/);
+    }
+  }
+}
+
+#exetime() returns time since last execution of this command
+#exetime(1) resets this time
+my $lasttime=-1;   # global variable for persistence
+sub exetime {
+  my $reset=0;
+  my $retval;
+  if ((scalar @_) >=1) {
+    $reset=shift;
+  }
+  if ($reset) {
+    $lasttime=times();
+  }
+  else {
+    $retval=times()-$lasttime;
+    $lasttime=$lasttime+$retval;
+    return($retval);
+  }
+}
+
+
+sub usage {
+  die <<"EOF"; 
+Usage: $0 [options] old.tex new.tex > diff.tex
+
+Compares two latex files and writes tex code to stdout, which has the same
+format as new.tex but has all changes relative to old.tex marked up or commented.
+
+--type=markupstyle
+-t markupstyle         Add code to preamble for selected markup style
+                       Available styles: UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+                                         CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR
+                       [ Default: UNDERLINE ]
+
+--subtype=markstyle
+-s markstyle           Add code to preamble for selected style for bracketing
+                       commands (e.g. to mark changes in  margin)
+                       Available styles: SAFE MARGINAL DVIPSCOL
+                       [ Default: SAFE ]
+
+--floattype=markstyle
+-f markstyle           Add code to preamble for selected style which 
+                       replace standard marking and markup commands within floats
+                       (e.g., marginal remarks cause an error within floats
+                       so marginal marking can be disabled thus)
+                       Available styles: FLOATSAFE IDENTICAL
+                       [ Default: FLOATSAFE ]
+
+--encoding=enc
+-e enc                 Specify encoding of old.tex and new.tex. Typical encodings are
+                       ascii, utf8, latin1, latin9.  A list of available encodings can be 
+                       obtained by executing 
+                       perl -MEncode -e 'print join ("\\n",Encode->encodings( ":all" )) ;'
+                       [Default encoding is utf8 unless the first few lines of the preamble contain
+                       an invocation "\\usepackage[..]{inputenc} in which case the 
+                       encoding chosen by this command is asssumed. Note that ASCII (standard
+                       latex) is a subset of utf8]
+
+--preamble=file
+-p file                Insert file at end of preamble instead of auto-generating
+                       preamble.  The preamble must define the following commands
+                       \\DIFaddbegin,\\DIFaddend,\\DIFadd{..},
+                       \\DIFdelbegin,\\DIFdelend,\\DIFdel{..},
+                       and varieties for use within floats
+                       \\DIFaddbeginFL,\\DIFaddendFL,\\DIFaddFL{..},
+                       \\DIFdelbeginFL,\\DIFdelendFL,\\DIFdelFL{..}
+                       (If this option is set -t, -s, and -f options
+                       are ignored.)
+
+--exclude-safecmd=exclude-file
+--exclude-safecmd="cmd1,cmd2,..."
+-A exclude-file 
+--replace-safecmd=replace-file
+--append-safecmd=append-file
+--append-safecmd="cmd1,cmd2,..."
+-a append-file         Exclude from, replace or append to the list of regex
+                       matching commands which are safe to use within the 
+                       scope of a \\DIFadd or \\DIFdel command.  The file must contain
+                       one Perl-RegEx per line (Comment lines beginning with # or % are
+                       ignored). A literal comma within the comma-separated list must be
+                       escaped thus "\\,",   Note that the RegEx needs to match the whole of 
+                       the token, i.e., /^regex\$/ is implied and that the initial
+                       "\\" of the command is not included. The --exclude-safecmd
+                       and --append-safecmd options can be combined with the --replace-safecmd 
+                       option and can be used repeatedly to add cumulatively to the lists.
+
+--exclude-textcmd=exclude-file 
+--exclude-textcmd="cmd1,cmd2,..."
+-X exclude-file
+--replace-textcmd=replace-file
+--append-textcmd=append-file
+--append-textcmd="cmd1,cmd2,..."
+-x append-file         Exclude from, replace or append to the list of regex
+                       matching commands whose last argument is text.  See
+                       entry for --exclude-safecmd directly above for further details.
+
+--replace-context1cmd=replace-file
+--append-context1cmd=append-file
+--append-context1cmd="cmd1,cmd2,..."
+                       Replace or append to the list of regex matching commands
+                       whose last argument is text but which require a particular
+                       context to work, e.g. \\caption will only work within a figure
+                       or table.  These commands behave like text commands, except when 
+                       they occur in a deleted section, when they are disabled, but their
+                       argument is shown as deleted text.
+
+--replace-context2cmd=replace-file
+--append-context2cmd=append-file
+--append-context2cmd="cmd1,cmd2,..."
+                       As corresponding commands for context1.  The only difference is that
+                       context2 commands are completely disabled in deleted sections, including
+                       their arguments.
+
+
+--config var1=val1,var2=val2,...
+-c var1=val1,..        Set configuration variables.
+-c configfile           Available variables: 
+                          MINWORDSBLOCK (integer)
+                          FLOATENV (RegEx)
+                          PICTUREENV (RegEx)
+                          MATHENV (RegEx)
+                          MATHREPL (String)
+                          MATHARRENV (RegEx)
+                          MATHARRREPL (String)
+                          ARRENV (RegEx)
+                          COUNTERCMD (RegEx)
+                       This option can be repeated.
+
+
+--packages=pkg1,pkg2,..
+                       Tell latexdiff that .tex file is processed with the packages in list 
+                       loaded.  This is normally not necessary if the .tex file includes the
+                       preamble, as the preamble is automatically scanned for \\usepackage commands.
+                       Use of the --packages option disables automatic scanning, so if for any
+                       reason package specific parsing needs to be switched off, use --packages=none.
+                       The following packages trigger special behaviour:
+                       endfloat hyperref amsmath
+                       [ Default: scan the preamble for \\usepackage commands to determine
+                         loaded packages.]
+
+--show-preamble        Print generated or included preamble commands to stdout.
+
+--show-safecmd         Print list of regex matching and excluding safe commands.
+
+--show-textcmd         Print list of regex matching and excluding commands with text argument.
+
+--show-config          Show values of configuration variables
+
+--show-all             Show all of the above
+
+   NB For all --show commands, no old.tex or new.tex file needs to be given, and no 
+      differencing takes place.
+
+--allow-spaces         Allow spaces between bracketed or braced arguments to commands
+                       [Default requires arguments to directly follow each other without 
+                                intervening spaces]
+
+--flatten              Replace \\input and \\include commands within body by the content
+                       of the files in their argument.  If \\includeonly is present in the
+                       preamble, only those files are expanded into the document. However, 
+                       no recursion is done, i.e. \\input and \\include commands within 
+                       included sections are not expanded.  The included files are assumed to 
+                       be located in the same directories as the old and new master files,
+                       respectively, making it possible to organise files into old and new directories.
+
+--help
+-h                     Show this help text.
+
+--ignore-warnings      Suppress warnings about inconsistencies in length between input
+                       and parsed strings and missing characters. 
+
+--verbose
+-V                     Output various status information to stderr during processing.
+                       Default is to work silently.
+
+--version              Show version number.
+EOF
+}
+
+=head1 NAME
+
+latexdiff - determine and markup differences between two latex files
+
+=head1 SYNOPSIS
+
+B<latexdiff> [ B<OPTIONS> ] F<old.tex> F<new.tex> > F<diff.tex>
+
+=head1 DESCRIPTION
+
+Briefly, I<latexdiff> is a utility program to aid in the management of
+revisions of latex documents. It compares two valid latex files, here
+called C<old.tex> and C<new.tex>, finds significant differences
+between them (i.e., ignoring the number of white spaces and position
+of line breaks), and adds special commands to highlight the
+differences.  Where visual highlighting is not possible, e.g. for changes
+in the formatting, the differences are
+nevertheless marked up in the source.
+
+The program treats the preamble differently from the main document.
+Differences between the preambles are found using line-based
+differencing (similarly to the Unix diff command, but ignoring white
+spaces).  A comment, "S<C<%DIF E<gt>>>" is appended to each added line, i.e. a 
+line present in C<new.tex> but not in C<old.tex>.  Discarded lines 
+ are deactivated by prepending "S<C<%DIF E<lt>>>". Changed blocks are preceded  by
+comment lines giving information about line numbers in the original files.  Where there are insignificant
+differences, the resulting file C<diff.tex> will be similar to
+C<new.tex>.  At the end of the preamble, the definitions for I<latexdiff> markup commands are inserted.
+In differencing the main body of the text, I<latexdiff> attempts to
+satisfy the following guidelines (in order of priority):
+
+=over 3
+
+=item 1
+
+If both C<old.tex> and C<new.tex> are valid LaTeX, then the resulting
+C<diff.tex> should also be valid LateX. (NB If a few plain TeX commands
+are used within C<old.tex> or C<new.tex> then C<diff.tex> is not
+guaranteed to work but usually will).
+
+=item 2
+
+Significant differences are determined on the level of
+individual words. All significant differences, including differences
+between comments should be clearly marked in the resulting source code
+C<diff.tex>.
+
+=item 3
+
+If a changed passage contains text or text-producing commands, then
+running C<diff.tex> through LateX should produce output where added
+and discarded passages are highlighted.
+
+=item 4
+
+Where there are insignificant differences, e.g. in the positioning of
+line breaks, C<diff.tex> should follow the formatting of C<new.tex>
+
+=back
+
+For differencing the same algorithm as I<diff> is used but words
+instead of lines are compared.  An attempt is made to recognize
+blocks which are completely changed such that they can be marked up as a unit.
+Comments are differenced line by line
+but the number of spaces within comments is ignored. Commands including
+all their arguments are generally compared as one unit, i.e., no mark-up
+is inserted into the arguments of commands.  However, for a selected
+number of commands (for example, C<\caption> and all sectioning
+commands) the last argument is known to be text. This text is
+split into words and differenced just as ordinary text (use options to
+show and change the list of text commands, see below). As the
+algorithm has no detailed knowledge of LaTeX, it assumes all pairs of
+curly braces immediately following a command (i.e. a sequence of
+letters beginning with a backslash) are arguments for that command.
+As a restriction to condition 1 above it is thus necessary to surround
+all arguments with curly braces, and to not insert
+extraneous spaces.  For example, write 
+
+  \section{\textem{This is an emphasized section title}}
+
+and not
+
+  \section {\textem{This is an emphasized section title}}
+
+or
+
+  \section\textem{This is an emphasized section title}
+
+even though all varieties are the same to LaTeX (but see
+B<--allow-spaces> option which allows the second variety).
+
+For environments whose content does not conform to standard LaTeX or
+where graphical markup does not make sense all markup commands can be
+removed by setting the PICTUREENV configuration variable, set by
+default to C<picture> and C<DIFnomarkup> environments; see B<--config>
+option).  The latter environment (C<DIFnomarkup>) can be used to
+protect parts of the latex file where the markup results in illegal
+markup. You have to surround the offending passage in both the old and
+new file by C<\begin{DIFnomarkup}> and C<\end{DIFnomarkup}>. You must
+define the environment in the preambles of both old and new
+documents. I prefer to define it as a null-environment,
+
+C<\newenvironment{DIFnomarkup}{}{}>
+
+but the choice is yours.  Any markup within the environment will be
+removed, and generally everything within the environment will just be
+taken from the new file.
+
+It is also possible to difference files which do not have a preamble. 
+ In this case, the file is processed in the main document
+mode, but the definitions of the markup commands are not inserted.
+
+All markup commands inserted by I<latexdiff> begin with "C<\DIF>".  Added
+blocks containing words, commands or comments which are in C<new.tex>
+but not in C<old.tex> are marked by C<\DIFaddbegin> and C<\DIFaddend>.
+Discarded blocks are marked by C<\DIFdelbegin> and C<\DIFdelend>.
+Within added blocks all text is highlighted with C<\DIFadd> like this:
+C<\DIFadd{Added text block}>
+Selected `safe' commands can be contained in these text blocks as well
+(use options to show and change the list of safe commands, see below).
+All other commands as well as braces "{" and "}" are never put within
+the scope of C<\DIFadd>.  Added comments are marked by prepending
+"S<C<%DIF E<gt> >>".
+
+Within deleted blocks text is highlighted with C<\DIFdel>.  Deleted
+comments are marked by prepending "S<C<%DIF E<lt> >>".  Non-safe command
+and curly braces within deleted blocks are commented out with 
+"S<C<%DIFDELCMD E<lt> >>".
+
+
+
+=head1 OPTIONS
+
+=head2 Preamble
+
+The following options determine the visual markup style by adding the appropriate
+command definitions to the preamble. See the end of this section for a description of 
+available styles.
+
+=over 4
+
+=item B<--type=markupstyle> or
+B<-t markupstyle>
+
+Add code to preamble for selected markup style. This option defines
+C<\DIFadd> and C<\DIFdel> commands.
+Available styles: 
+
+C<UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR>
+
+[ Default: C<UNDERLINE> ]
+
+=item B<--subtype=markstyle> or
+B<-s markstyle> 
+
+Add code to preamble for selected style for bracketing
+commands (e.g. to mark changes in  margin). This option defines
+C<\DIFaddbegin>, C<\DIFaddend>, C<\DIFdelbegin> and C<\DIFdelend> commands.
+Available styles: C<SAFE MARGINAL DVIPSCOL>
+
+[ Default: C<SAFE> ]
+
+=item B<--floattype=markstyle> or
+B<-f markstyle>
+
+Add code to preamble for selected style which 
+replace standard marking and markup commands within floats
+(e.g., marginal remarks cause an error within floats
+so marginal marking can be disabled thus). This option defines all 
+C<\DIF...FL> commands.
+Available styles: C<FLOATSAFE TRADITIONALSAFE IDENTICAL>
+
+[ Default: C<FLOATSAFE> ]
+
+=item B<--encoding=enc> or 
+B<-e enc>
+
+Specify encoding of old.tex and new.tex. Typical encodings are
+C<ascii>, C<utf8>, C<latin1>, C<latin9>.  A list of available encodings can be 
+obtained by executing 
+
+C<perl -MEncode -e 'print join ("\n",Encode->encodings( ":all" )) ;' >
+
+[Default encoding is utf8 unless the first few lines of the preamble contain
+an invocation C<\usepackage[..]{inputenc}> in which case the 
+encoding chosen by this command is asssumed. Note that ASCII (standard
+latex) is a subset of utf8]
+
+=item B<--preamble=file> or
+B<-p file>
+
+Insert file at end of preamble instead of generating
+preamble.  The preamble must define the following commands
+C<\DIFaddbegin, \DIFaddend, \DIFadd{..},
+\DIFdelbegin,\DIFdelend,\DIFdel{..},>
+and varieties for use within floats
+C<\DIFaddbeginFL, \DIFaddendFL, \DIFaddFL{..},
+\DIFdelbeginFL, \DIFdelendFL, \DIFdelFL{..}>
+(If this option is set B<-t>, B<-s>, and B<-f> options
+are ignored.)
+
+=item B<--packages=pkg1,pkg2,..> 
+
+Tell latexdiff that .tex file is processed with the packages in list
+loaded.  This is normally not necessary if the .tex file includes the
+preamble, as the preamble is automatically scanned for C<\usepackage> commands.
+Use of the B<--packages> option disables automatic scanning, so if for any
+reason package specific parsing needs to be switched off, use B<--packages=none>.
+The following packages trigger special behaviour:
+
+=over 8
+
+=item C<amsmath> 
+
+Configuration variable amsmath is set to C<align*> (Default: C<eqnarray*>)
+
+=item C<endfloat> 
+
+Ensure that C<\begin{figure}> and C<\end{figure}> always appear by themselves on a line.
+
+=item C<hyperref>
+
+Change name of C<\DIFadd> and C<\DIFdel> commands to C<\DIFaddtex> and C<\DIFdeltex> and 
+define new C<\DIFadd> and C<\DIFdel> commands, which provide a wrapper for these commands,
+using them for the text but not for the link defining command (where any markup would cause
+errors).
+
+=back
+
+[ Default: scan the preamble for C<\\usepackage> commands to determine
+  loaded packages.]
+
+
+
+=item B<--show-preamble>
+
+Print generated or included preamble commands to stdout.
+
+=back
+
+=head2 Configuration
+
+=over 4
+
+=item B<--exclude-safecmd=exclude-file> or
+B<-A exclude-file> or  B<--exclude-safecmd="cmd1,cmd2,...">
+
+=item B<--replace-safecmd=replace-file>
+
+=item B<--append-safecmd=append-file> or 
+B<-a append-file> or B<--append-safecmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions (RegEx)
+matching commands which are safe to use within the 
+scope of a C<\DIFadd> or C<\DIFdel> command.  The file must contain
+one Perl-RegEx per line (Comment lines beginning with # or % are
+ignored).  Note that the RegEx needs to match the whole of 
+the token, i.e., /^regex$/ is implied and that the initial
+"\" of the command is not included. 
+The B<--exclude-safecmd> and B<--append-safecmd> options can be combined with the -B<--replace-safecmd> 
+option and can be used repeatedly to add cumulatively to the lists.
+ B<--exclude-safecmd>
+and B<--append-safecmd> can also take a comma separated list as input. If a
+comma for one of the regex is required, escape it thus "\,". In most cases it
+will be necessary to protect the comma-separated list from the shell by putting
+it in quotation marks.
+
+=item B<--exclude-textcmd=exclude-file> or
+B<-X exclude-file> or B<--exclude-textcmd="cmd1,cmd2,...">
+
+=item B<--replace-textcmd=replace-file>
+
+=item B<--append-textcmd=append-file> or 
+B<-x append-file> or B<--append-textcmd="cmd1,cmd2,...">
+
+Exclude from, replace or append to the list of regular expressions
+matching commands whose last argument is text.  See
+entry for B<--exclude-safecmd> directly above for further details.
+
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context1cmd=append-file> or
+=item B<--append-context1cmd="cmd1,cmd2,...">
+
+Replace or append to the list of regex matching commands
+whose last argument is text but which require a particular
+context to work, e.g. \caption will only work within a figure
+or table.  These commands behave like text commands, except when 
+they occur in a deleted section, when they are disabled, but their
+argument is shown as deleted text.
+
+=item B<--replace-context1cmd=replace-file> 
+
+=item B<--append-context2cmd=append-file> or
+=item B<--append-context2cmd="cmd1,cmd2,...">
+As corresponding commands for context1.  The only difference is that
+context2 commands are completely disabled in deleted sections, including
+their arguments.
+
+
+
+=item B<--config var1=val1,var2=val2,...> or B<-c var1=val1,..>
+
+=item B<-c configfile>
+
+Set configuration variables.  The option can be repeated to set different
+variables (as an alternative to the comma-separated list).
+Available variables (see below for further explanations): 
+
+C<MINWORDSBLOCK> (integer)
+
+C<FLOATENV> (RegEx)
+
+C<PICTUREENV> (RegEx)
+
+C<MATHENV> (RegEx)
+
+C<MATHREPL> (String)
+
+C<MATHARRENV> (RegEx)
+
+C<MATHARRREPL> (String)
+
+C<ARRENV> (RegEx)
+
+C<COUNTERCMD> (RegEx)
+
+=item B<--show-safecmd>
+
+Print list of RegEx matching and excluding safe commands.
+
+=item B<--show-textcmd>
+
+Print list of RegEx matching and excluding commands with text argument.
+
+=item B<--show-config>
+
+Show values of configuration variables.
+
+=item B<--show-all>
+
+Combine all --show commands.
+
+NB For all --show commands, no C<old.tex> or C<new.tex> file needs to be specified, and no 
+differencing takes place.
+
+
+=back
+
+=head2 Miscellaneous
+
+=over 4
+
+=item B<--verbose> or B<-V>
+
+Output various status information to stderr during processing.
+Default is to work silently.
+
+=item B<--ignore-warnings>
+
+Suppress warnings about inconsistencies in length between input and
+parsed strings and missing characters.  These warning messages are
+often related to non-standard latex or latex constructions with a
+syntax unknown to C<latexdiff> but the resulting difference argument
+is often fully functional anyway, particularly if the non-standard
+latex only occurs in parts of the text which have not changed.
+
+=item B<--allow-spaces>
+
+Allow spaces between bracketed or braced arguments to commands.  Note
+that this option might have undesirable side effects (unrelated scope
+might get lumpeded with preceding commands) so should only be used if the
+default produces erroneous results.  (Default requires arguments to
+directly follow each other without intervening spaces).
+
+=item B<--flatten>
+
+Replace C<\input> and C<\include> commands within body by the content
+of the files in their argument.  If C<\includeonly> is present in the
+preamble, only those files are expanded into the document. However, 
+no recursion is done, i.e. C<\input> and C<\include> commands within 
+included sections are not expanded.  The included files are assumed to 
+ be located in the same directories as the old and new master files,
+respectively, making it possible to organise files into old and new directories. 
+
+Use of this option is not recommended
+primarily the processing time for the large documents is prohibitive, and
+the resulting difference document no longer reflects the structure of the 
+input documents. 
+
+=item B<--help> or
+B<-h>
+
+Show help text
+
+=item B<--version>
+
+Show version number
+
+=back
+
+=head2 Predefined styles 
+
+=head2 Major types
+
+The major type determine the markup of plain text and some selected latex commands outside floats by defining the markup commands C<\DIFadd{...}> and C<\DIFdel{...}> .
+
+=over 10
+
+=item C<UNDERLINE>
+
+Added text is wavy-underlined and blue, discarded text is struck out and red
+(Requires color and ulem packages).  Overstriking does not work in displayed math equations such that deleted parts of equation are underlined, not struck out (this is a shortcoming inherent to the ulem package).
+
+=item C<CTRADITIONAL>
+
+Added text is blue and set in sans-serif, and a red footnote is created for each discarded 
+piece of text. (Requires color package)
+
+=item C<TRADITIONAL>
+
+Like C<CTRADITIONAL> but without the use of color.
+
+=item C<CFONT>
+
+Added text is blue and set in sans-serif, and discarded text is red and very small size.
+
+=item C<FONTSTRIKE>
+
+Added tex is set in sans-serif, discarded text small and struck out
+
+=item C<CCHANGEBAR>
+
+Added text is blue, and discarded text is red.  Additionally, the changed text is marked with a bar in the margin (Requires color and changebar packages).
+
+=item C<CFONTCHBAR>
+
+Like C<CFONT> but with additional changebars (Requires color and changebar packages).
+
+=item C<CULINECHBAR>
+
+Like C<UNDERLINE> but with additional changebars (Requires color, ulem and changebar packages).
+
+=item C<CHANGEBAR>
+
+No mark up of text, but mark margins with changebars (Requires changebar package).
+
+=item C<INVISIBLE>
+
+No visible markup (but generic markup commands will still be inserted.
+
+=back
+
+=head2 Subtypes
+
+The subtype defines the commands that are inserted at the begin and end of added or discarded blocks, irrespectively of whether these blocks contain text or commands (Defined commands: C<\DIFaddbegin, \DIFaddend, \DIFdelbegin, \DIFdelend>) 
+
+=over 10
+
+=item C<SAFE>
+
+No additional markup (Recommended choice)
+
+=item C<MARGIN>
+
+Mark beginning and end of changed blocks with symbols in the margin nearby (using
+the standard C<\marginpar> command - note that this sometimes moves somewhat
+from the intended position.
+
+=item C<DVIPSCOL>
+
+An alternative way of marking added passages in blue, and deleted ones in red. Note
+that C<DVIPSCOL> only works with the dvips converter, e.g. not pdflatex.
+(it is recommeneded to use instead the main types to effect colored markup,
+although in some cases coloring with dvipscol can be more complete).
+
+=back
+
+=head2 Float Types
+
+Some of the markup used in the main text might cause problems when used within 
+floats (e.g. figures or tables).  For this reason alternative versions of all
+markup commands are used within floats. The float type defines these alternative commands.
+
+=over 10
+
+=item C<FLOATSAFE>
+
+Use identical markup for text as in the main body, but set all commands marking the begin and end of changed blocks to null-commands.  You have to choose this float type if your subtype is C<MARGIN> as C<\marginpar> does not work properly within floats.
+
+=item C<TRADITIONALSAFE>
+
+Mark additions the same way as in the main text.  Deleted environments are marked by angular brackets \[ and \] and the deleted text is set in scriptscript size. This float type should always be used with the C<TRADITIONAL> and  C<CTRADITIONAL> markup types as the \footnote command does not work properly in floating environments.
+
+=item C<IDENTICAL>
+
+Make no difference between the main text and floats.
+
+=back
+
+
+=head2 Configuration Variables
+
+=over 10
+
+=item C<MINWORDSBLOCK>
+
+Minimum number of tokens required to form an independent block. This value is
+used in the algorithm to detect changes of complete blocks by merging identical text parts of less than C<MINWORDSBLOCK> to the preceding added and discarded parts.
+
+[ Default: 3 ]
+
+=item C<FLOATENV>
+
+Environments whose name matches the regular expression in C<FLOATENV> are 
+considered floats.  Within these environments, the I<latexdiff> markup commands
+are replaced by their FL variaties.
+
+[ Default: S<C<(?:figure|table|plate)[\w\d*@]*> >]
+
+=item C<PICTUREENV>
+
+Within environments whose name matches the regular expression in C<PICTUREENV>
+all latexdiff markup is removed (in pathologic cases this might lead to
+ inconsistent markup but this situation should be rare).
+
+[ Default: S<C<(?:picture|DIFnomarkup)[\w\d*@]*> >]
+
+=item C<MATHENV>,C<MATHREPL>
+
+If both \begin and \end for a math environment (environment name matching C<MATHENV>
+or \[ and \])
+are within the same deleted block, they are replaced by a \begin and \end commands for C<MATHREPL>
+rather than being commented out.
+
+[ Default: C<MATHENV>=S<C<(?:displaymath|equation)> >, C<MATHREPL>=S<C<displaymath> >]
+
+=item C<MATHARRENV>,C<MATHARRREPL>
+
+as C<MATHENV>,C<MATHREPL> but for equation arrays
+
+[ Default: C<MATHARRENV>=S<C<eqnarray\*?> >, C<MATHREPL>=S<C<eqnarray> >]
+
+=item C<ARRENV>
+
+If a match to C<ARRENV> is found within an inline math environment within a deleted or added block, then the inlined math 
+is surrounded by C<\mbox{>...C<}>.  This is necessary as underlining does not work within inlined array environments.
+
+[ Default: C<ARRENV>=S<C<(?:array|[pbvBV]matrix)> >
+
+=item C<COUNTERCMD>
+
+If a command in a deleted block which is also in the textcmd list matches C<COUNTERCMD> then an
+additional command C<\addtocounter{>F<cntcmd>C<}{-1}>, where F<cntcmd> is the matching command, is appended in the diff file such that the numbering in the diff file remains synchronized with the
+numbering in the new file.
+
+[ Default: C<COUNTERCMD>=C<(?:footnote|part|section|subsection> ...
+
+C<|subsubsection|paragraph|subparagraph)>  ]
+
+=back
+
+=head1 BUGS
+
+UTF-8 support requires a relatively new version of perl (5.8.0 is sufficient 
+but 5.6.2 up would work OK, too).
+
+Option allow-spaces not implemented entirely consistently. It breaks
+the rules that number and type of white space does not matter, as
+different numbers of inter-argument spaces are treated as significant.
+
+Please send bug reports
+to I<tilmann@esc.cam.ac.uk>.  Include the serial number of I<latexdiff>
+(from comments at the top of the source or use B<--version>).  If you come across latex
+files that are error-free and conform to the specifications set out
+above, and whose differencing still does not result in error-free
+latex, please send me those files, ideally edited to only contain the
+offending passage as long as that still reproduces the problem. 
+
+=head1 SEE ALSO
+
+L<latexrevise>
+
+=head1 PORTABILITY
+
+I<latexdiff> does not make use of external commands and thus should run
+on any platform  supporting Perl 5.6 or higher.  If files with encodings 
+other than ASCII or UTF-8 are processed, Perl 5.8 or higher is required.
+
+The standard version of I<latexdiff> requires installation of the Perl package
+C<Algorithm::Diff> (available from I<www.cpan.org> - 
+I<http://search.cpan.org/~nedkonz/Algorithm-Diff-1.15>) but a stand-alone
+version, I<latexdiff-so>, which has this package inlined, is available, too.
+I<latexdiff-fast> requires the I<diff> command to be present.
+
+=head1 AUTHOR
+
+Copyright (C) 2004-2007 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+
+Contributors of fixes and additions: V. Kuhlmann, J. Paisley, N. Becker, T. Doerges, K. Huebner
+Thanks to everyone who send in bug reports.
+
+=cut
+
+__END__
+%%BEGIN SAFE COMMANDS
+% Regex matching commands which can safely be in the
+% argument of a \DIFadd or \DIFdel command (leave out the \)
+arabic
+dashbox
+emph
+fbox
+framebox
+hspace
+math.*
+makebox
+mbox
+pageref
+ref
+symbol
+raisebox
+rule
+text.*
+shortstack
+usebox
+dag
+ddag
+copyright
+pounds
+S
+P
+oe
+OE
+ae
+AE
+aa
+AA
+o
+O
+l
+L
+frac
+ss
+sqrt
+ldots
+cdots
+vdots
+ddots
+alpha
+beta
+gamma
+delta
+epsilon
+varepsilon
+zeta
+eta
+theta
+vartheta
+iota
+kappa
+lambda
+mu
+nu
+xi
+pi
+varpi
+rho
+varrho
+sigma
+varsigma
+tau
+upsilon
+phi
+varphi
+chi
+psi
+omega
+Gamma
+Delta
+Theta
+Lambda
+Xi
+Pi
+Sigma
+Upsilon
+Phi
+Psi
+Omega
+ps
+mp
+times
+div
+ast
+star
+circ
+bullet
+cdot
+cap
+cup
+uplus
+sqcap
+vee
+wedge
+setminus
+wr
+diamond
+(?:big)?triangle.*
+lhd
+rhd
+unlhd
+unrhd
+oplus
+ominus
+otimes
+oslash
+odot
+bigcirc
+d?dagger
+amalg
+leq
+prec
+preceq
+ll
+(?:sq)?su[bp]set(?:eq)?
+in
+vdash
+geq
+succ(?:eq)?
+gg
+ni
+dashv
+equiv
+sim(?:eq)?
+asymp
+approx
+cong
+neq
+doteq
+propto
+models
+perp
+mid
+parallel
+bowtie
+Join
+smile
+frown
+.*arrow
+(?:long)?mapsto
+.*harpoon.*
+leadsto
+aleph
+hbar
+imath
+jmath
+ell
+wp
+Re
+Im
+mho
+prime
+emptyset
+nabla
+surd
+top
+bot
+angle
+forall
+exists
+neg
+flat
+natural
+sharp
+backslash
+partial
+infty
+Box
+Diamond
+triangle
+clubsuit
+diamondsuit
+heartsuit
+spadesuit
+sum
+prod
+coprod
+int
+oint
+big(?:sq)?c[au]p
+bigvee
+bigwedge
+bigodot
+bigotimes
+bigoplus
+biguplus
+(?:arc)?(?:cos|sin|tan|cot)h?
+csc
+arg
+deg
+det
+dim
+exp
+gcd
+hom
+inf
+ker
+lg
+lim
+liminf
+limsup
+ln
+log
+max
+min
+Pr
+sec
+sup
+(SUPER|SUB)SCRIPTNB
+(SUPER|SUB)SCRIPT
+%%END SAFE COMMANDS
+
+%%BEGIN TEXT COMMANDS
+% Regex matching commands with a text argument (leave out the \)
+addcontents.*
+cc
+closing
+chapter
+dashbox
+emph
+encl
+fbox
+framebox
+footnote
+footnotetext
+framebox
+part
+(sub){0,2}section\*?
+(sub)?paragraph\*?
+makebox
+mbox
+opening
+parbox
+raisebox
+savebox
+sbox
+shortstack
+signature
+text.*
+value
+underline
+sqrt
+(SUPER|SUB)SCRIPT
+%%END TEXT COMMANDS 
+
+%%BEGIN CONTEXT1 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+caption
+%%END CONTEXT1 COMMANDS 
+
+%%BEGIN CONTEXT2 COMMANDS
+% Regex matching commands with a text argument (leave out the \), which will fail out of context, but who's arguemtn should be printed as plain text
+title
+author
+%%END CONTEXT2 COMMANDS 
+
+
+%% TYPES (Commands for highlighting changed blocks)
+
+%DIF UNDERLINE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue}\uwave{#1}}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}\sout{#1}}}                     
+%DIF END UNDERLINE PREAMBLE
+
+%DIF CTRADITIONAL PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} [..\footnote{removed: #1} ]}}
+%DIF END CTRADITIONAL PREAMBLE
+
+%DIF TRADITIONAL PREAMBLE
+\RequirePackage[stable]{footmisc}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{[..\footnote{removed: #1} ]}}
+%DIF END TRADITIONAL PREAMBLE
+
+%DIF CFONT PREAMBLE
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{{\protect\color{blue} \sf #1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red} \scriptsize #1}}
+%DIF END CFONT PREAMBLE
+
+%DIF FONTSTRIKE PREAMBLE
+\RequirePackage[normalem]{ulem}
+\providecommand{\DIFadd}[1]{{\sf #1}}
+\providecommand{\DIFdel}[1]{{\footnotesize \sout{#1}}}
+%DIF END FONTSTRIKE PREAMBLE
+
+%DIF CCHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}#1}\protect\cbdelete}
+%DIF END CCHANGEBAR PREAMBLE
+
+%DIF CFONTCHBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}\definecolor{RED}{rgb}{1,0,0}\definecolor{BLUE}{rgb}{0,0,1}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\sf #1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\scriptsize #1}\protect\cbdelete}
+%DIF END CFONTCHBAR PREAMBLE
+
+%DIF CULINECHBAR PREAMBLE
+\RequirePackage[normalem]{ulem}
+\RequirePackage[dvips]{changebar}
+\RequirePackage{color}
+\providecommand{\DIFadd}[1]{\protect\cbstart{\protect\color{blue}\uwave{#1}}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete{\protect\color{red}\sout{#1}}\protect\cbdelete}
+%DIF END CULINECHBAR PREAMBLE
+
+%DIF CHANGEBAR PREAMBLE
+\RequirePackage[dvips]{changebar}
+\providecommand{\DIFadd}[1]{\protect\cbstart{#1}\protect\cbend}
+\providecommand{\DIFdel}[1]{\protect\cbdelete}
+%DIF END CHANGEBAR PREAMBLE
+
+%DIF INVISIBLE PREAMBLE
+\providecommand{\DIFadd}[1]{#1}
+\providecommand{\DIFdel}[1]{}
+%DIF END INVISIBLE PREAMBLE
+
+
+%% SUBTYPES (Markers for beginning and end of changed blocks)
+
+%DIF SAFE PREAMBLE
+\providecommand{\DIFaddbegin}{}
+\providecommand{\DIFaddend}{}
+\providecommand{\DIFdelbegin}{}
+\providecommand{\DIFdelend}{}
+%DIF END SAFE PREAMBLE
+
+%DIF MARGIN PREAMBLE
+\providecommand{\DIFaddbegin}{\protect\marginpar{a[}}
+\providecommand{\DIFaddend}{\protect\marginpar{]}}
+\providecommand{\DIFdelbegin}{\protect\marginpar{d[}}
+\providecommand{\DIFdelend}{\protect\marginpar{]}}
+%DIF END BRACKET PREAMBLE
+
+%DIF DVIPSCOL PREAMBLE
+%Note: only works with dvips converter
+\RequirePackage{color}
+\RequirePackage{dvipscol}
+\providecommand{\DIFaddbegin}{\protect\nogroupcolor{blue}}
+\providecommand{\DIFaddend}{\protect\nogroupcolor{black}}
+\providecommand{\DIFdelbegin}{\protect\nogroupcolor{red}}
+\providecommand{\DIFdelend}{\protect\nogroupcolor{black}}
+%DIF END DVIPSCOL PREAMBLE
+
+
+%% FLOAT TYPES 
+
+%DIF FLOATSAFE PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%DIF IDENTICAL PREAMBLE
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
+\providecommand{\DIFaddbeginFL}{\DIFaddbegin}
+\providecommand{\DIFaddendFL}{\DIFaddend}
+\providecommand{\DIFdelbeginFL}{\DIFdelbegin}
+\providecommand{\DIFdelendFL}{\DIFdelend}
+%DIF END IDENTICAL PREAMBLE
+
+%DIF TRADITIONALSAFE PREAMBLE
+% procidecommand color to make this work for TRADITIONAL and CTRADITIONAL
+\providecommand{\color}[1]{}
+\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
+\providecommand{\DIFdel}[1]{{\protect\color{red}[..{\scriptsize {removed: #1}} ]}}
+\providecommand{\DIFaddbeginFL}{}
+\providecommand{\DIFaddendFL}{}
+\providecommand{\DIFdelbeginFL}{}
+\providecommand{\DIFdelendFL}{}
+%DIF END FLOATSAFE PREAMBLE
+
+%% SPECIAL PACKAGE PREAMBLE COMMANDS
+
+% Standard \DIFadd and \DIFdel are redefined as \DIFaddtex and \DIFdeltex
+% when hyperref package is included.
+%DIF HYPERREF PREAMBLE
+\providecommand{\DIFadd}[1]{\texorpdfstring{\DIFaddtex{#1}}{#1}}
+\providecommand{\DIFdel}[1]{\texorpdfstring{\DIFdeltex{#1}}{}}
+%DIF END HYPERREF PACKAGE
diff --git a/Master/texmf-dist/scripts/latexdiff/latexrevise b/Master/texmf-dist/scripts/latexdiff/latexrevise
new file mode 100755
index 00000000000..279dac1fc6a
--- /dev/null
+++ b/Master/texmf-dist/scripts/latexdiff/latexrevise
@@ -0,0 +1,523 @@
+#!/usr/bin/perl -w
+#   latexrevise - takes output file of latexdiff and removes either discarded
+#                 or appended passages, then deletes all other latexdiff markup
+#
+#   Copyright (C) 2004  F J Tilmann (tilmann@esc.cam.ac.uk)
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License Version 2 as published by
+#    the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Detailed usage information at the end of the file
+#
+# Version 0.1   First public release
+# Version 0.3   Updated for compatibility with latexdiff 0.3 output (DIFAUXCMD removal)
+#
+
+use Getopt::Long ;
+use strict;
+
+# Markup strings (make sure that this are set to the same value as in 
+# latexdiff)
+# If at all possible, do not change these as parts of the program
+# depend on the actual name.
+# At the very least adapt subroutine postprocess to new tokens.
+
+# note: have to use three backslashes to mean one literal one (reason
+# unknown
+my $ADDMARKOPEN='\\\DIFaddbegin(?:FL)? ';   # Token to mark begin of appended text
+my $ADDMARKCLOSE='\\\DIFaddend(?:FL)?(?: |\z)';   # Token to mark end of appended text (|\z only deals with the case of \DIFaddend right before \end{document}
+my $ADDOPEN='\\\DIFadd(?:FL)?{';  # To mark begin of added text passage
+my $ADDCLOSE='}';        # To mark end of added text passage
+my $ADDCOMMENT='DIF > ';   # To mark added comment line
+my $DELMARKOPEN='\\\DIFdelbegin(?:FL)? ';   # Token to mark begin of deleted text
+my $DELMARKCLOSE='\\\DIFdelend(?:FL)?(?: |\z)';   # Token to mark end of deleted text
+my $DELOPEN='\\\DIFdel(?:FL)?{';  # To mark begin of deleted text passage
+my $DELCLOSE='}';        # To mark end of deleted text passage
+my $ALTEXT='FL';         # string which might be appended to above commands
+my $DELCMDOPEN='%DIFDELCMD < ';  # To mark begin of deleted commands (must begin with %, i.e., be a comment
+my $DELCMDCLOSE="%%%\n";    # To mark end of deleted commands (must end with a new line)
+my $AUXCMD='%DIFAUXCMD' ; #  follows auxiliary commands put in by latexdiff to make difference file legal
+my $DELCOMMENT='DIF < ';   # To mark deleted comment line
+
+my $PREAMBLEXTBEG='^%DIF PREAMBLE EXTENSION ADDED BY LATEXDIFF$';
+my $PREAMBLEXTEND='^%DIF END PREAMBLE EXTENSION ADDED BY LATEXDIFF$';
+
+
+my $pat0 = '(?:[^{}]|\\\{|\\\})*';
+my $pat1 = '(?:[^{}]|\\\{|\\\}|\{'.$pat0.'\})*';
+my $pat2 = '(?:[^{}]|\\\{|\\\}|\{'.$pat1.'\})*';
+my $pat3 = '(?:[^{}]|\\\{|\\\}|\{'.$pat2.'\})*';
+my $pat4 = '(?:[^{}]|\\\{|\\\}|\{'.$pat3.'\})*';
+my $brat0 = '(?:[^\[\]]|\\\[|\\\])*'; 
+
+
+my ($input,$preamble,$body,$post);
+my (@matches);
+my ($cnt,$prematch,$postmatch);
+my ($help);
+my ($verbose,$quiet,$accept,$decline,$simplify)=(0,0,0,0,0);
+my ($comment,$comenv,$markup,$markenv);
+
+# A word unlikely ever to be used in a real latex file
+my $someword='gobbledegooksygook';
+
+Getopt::Long::Configure('bundling');
+GetOptions('accept|a' => \$accept,
+	   'decline|d'=> \$decline,
+	   'simplify|s' => \$simplify,
+	   'comment|c=s' => \$comment,
+	   'comment-environment|e=s' => \$comenv,
+	   'markup|m=s' => \$markup,
+	   'markup-environment|n=s' => \$markenv,
+	   'no-warnings|q' => \$verbose,
+	   'verbose|V' => \$verbose,
+	   'help|h|H' => \$help);
+
+if ( $help ) {
+  usage() ;
+}
+
+if ( ($accept &&  $decline) || ($accept && $simplify) || ($decline && $simplify) ) {
+  die '-a,-d and -s options are mutually axclusive. Type latexrevise -h to get more help.';
+}
+
+
+
+print STDERR "ACCEPT mode\n" if $verbose && $accept;
+print STDERR "DECLINE mode\n" if $verbose && $decline;
+print STDERR "SIMPLIFY mode.  WARNING: The output will not normally be valid latex,\n" if $verbose && $simplify;
+
+# Slurp old and new files
+{ 
+  local $/ ; # locally set record operator to undefined, ie. enable whole-file mode
+  $input=<>;
+}
+
+# split into parts
+($preamble,$body,$post)=splitdoc($input,'\begin{document}','\end{document}');
+
+if (length $preamble && ( $accept || $decline ) ) {
+  #
+  # WORK ON PREAMBLE
+  #
+  # (compare subroutine linediff in latexdiff to make sure correct strings are used)
+  
+  # remove extra commands added to preamble by latexdiff 
+  $preamble =~ s/${PREAMBLEXTBEG}.*?${PREAMBLEXTEND}\n{0,1}//smg ;
+
+  if ( $accept ) {
+    # delete mark up in appended lines
+    $preamble =~ s/^(.*) %DIF > $/$1/mg ;
+  } elsif ( $decline ) {
+    # delete appended lines
+    #  $preamble =~ s/^(.*) %DIF > $//mg ;
+    $preamble =~ s/^(.*) %DIF > \n//mg ;
+    # delete markup in deleted lines
+    $preamble =~ s/^%DIF < //mg ;
+  }
+  # remove any remaining DIF markups
+  #$preamble =~ s/%DIF.*$//mg ;
+  $preamble =~ s/%DIF.*?\n//sg ;
+}
+#print $preamble ;
+
+#
+# WORK ON BODY
+#
+if ($accept) {
+  # remove ADDMARKOPEN, ADDMARKCLOSE tokens
+  @matches= $body =~ m/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/sg;
+  checkpure(@matches);
+  $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/$1/sg;
+  # remove text flanked by DELMARKOPEN, DELMARKCLOSE tokens
+  @matches= $body =~ m/${DELMARKOPEN}(.*?)${DELMARKCLOSE}/sg;
+  checkpure(@matches);
+  $body =~ s/${DELMARKOPEN}(.*?)${DELMARKCLOSE}//sg;
+  # remove markup of added comments
+  $body =~ s/%${ADDCOMMENT}(.*?)$/%$1/mg ;
+  # remove deleted comments (full line)
+  $body =~ s/^%${DELCOMMENT}.*?\n//mg ;
+  # remove deleted comments (part of line)
+  $body =~ s/%${DELCOMMENT}.*?$//mg ;
+} 
+elsif ( $decline) {
+  # remove DELMARKOPEN, DELMARKCLOSE tokens
+  @matches= $body =~ m/${DELMARKOPEN}(.*?)${DELMARKCLOSE}/sg;
+  checkpure(@matches);
+  $body =~ s/${DELMARKOPEN}(.*?)${DELMARKCLOSE}/$1/sg;
+  # remove text flanked by ADDMARKOPEN, ADDMARKCLOSE tokens
+  # as latexdiff algorithm keeps the formatting and white spaces
+  # of the new text, sometimes whitespace might be inserted or
+  # removed inappropriately.  We try to guess whether this has
+  # happened
+
+  # Mop up tokens. This must be done already now as otherwise 
+  # detection of white-space problems does not work
+  $cnt = $body =~ s/${DELOPEN}($pat4)${DELCLOSE}/$1/sg;
+  # remove markup of deleted commands 
+  $cnt +=   $body =~ s/${DELCMDOPEN}(.*?)${DELCMDCLOSE}/$1/sg ;
+  $cnt +=   $body =~ s/${DELCMDOPEN}//g ;
+  # remove aux commands
+  $cnt +=   $body =~ s/^.*${AUXCMD}$/${someword}/mg; $body =~ s/${someword}\n//g;
+
+  while ( $body =~ m/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/s ) {
+    $prematch=$`;
+    $postmatch=$';
+    checkpure($1);
+    if ( $prematch =~ /\w$/s && $postmatch =~ /^\w/ ) {
+      # apparently no white-space between word=>Insert white space
+      $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/ /s ;
+    }
+    elsif ( $prematch =~ /\s$/s && $postmatch =~ /^[.,;:]/ ) {
+      # space immediately before one of ".,:;" => remove this space
+      $body =~ s/\s${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}//s ;
+    }
+    else {
+      # do not insert or remove any extras
+      $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}//s;
+    }
+  }
+# Alternative without special cases treatment
+#  @matches= $body =~ m/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}/sg;
+#  checkpure(@matches);
+#  $body =~ s/${ADDMARKOPEN}(.*?)${ADDMARKCLOSE}//sg;
+  # remove markup of deleted comments
+  $body =~ s/%${DELCOMMENT}(.*?)$/%$1/mg ;
+  # remove added comments (full line)
+  $body =~ s/^%${ADDCOMMENT}.*?\n//mg ;
+  # remove added comments (part of line)
+  $body =~ s/%${ADDCOMMENT}.*?$//mg ;
+}
+
+# remove any remaining tokens
+if ( $accept || $decline || $simplify ) {
+  # first substitution command deals with special case of added paragraph
+  $cnt = $body =~ s/${ADDOPEN}($pat4)\n${ADDCLOSE}\n/$1\n/sg;
+  $cnt += $body =~ s/${ADDOPEN}($pat4)${ADDCLOSE}/$1/sg;
+  $cnt==0 || warn 'Remaining $ADDOPEN tokens in DECLINE mode\n' unless ( $quiet || $accept || $simplify );
+}
+if ($accept || $simplify ) {
+  # Note: in decline mode these commands have already been removed above
+  $cnt = $body =~ s/${DELOPEN}($pat4)${DELCLOSE}/$1/sg;
+  #### remove markup of deleted commands 
+  $cnt +=   $body =~ s/${DELCMDOPEN}(.*?)${DELCMDCLOSE}/$1/sg ;
+  $cnt +=   $body =~ s/${DELCMDOPEN}//g ;
+  # remove aux commands
+  # $cnt +=   
+  $body =~ s/^.*${AUXCMD}$/${someword}/mg; $body =~ s/${someword}\n//g;
+
+  #### remove deleted comments 
+  ###$cnt += $body =~ s/${DIFDELCMD}.*?$//mg ;
+  $cnt==0 || warn 'Remaining $DELOPEN or $DIFDELCMD tokens in ACCEPT mode\n' unless ( $quiet || $simplify );
+}
+
+# Remove comment commands
+if (defined($comment)) {
+  print STDERR "Removing \\$comment\{..\} sequences ..." if $verbose;
+  # protect $comments in comments by making them look different
+  $body =~ s/(%.*)${comment}(.*)$/$1${someword}$2/mg ;
+  # carry out the substitution
+  $cnt = 0 + $body =~ s/\\${comment}(?:\[${brat0}\])?\{${pat4}\}//sg ;
+  print STDERR "$cnt matches found and removed.\n" if $verbose;
+  # and undo the protection substitution
+  $body =~ s/(%.*)${someword}(.*)$/$1${comment}$2/mg ;
+}
+if (defined($comenv)) {
+  print STDERR "Removing $comenv environments ..." if $verbose;
+  $body =~ s/(%.*)${comenv}/$1${someword}/mg ;
+##  $cnt = 0 + $body =~ s/\\begin(?:\[${brat0}\])?\{\$comenv\}.*?\\end\{\$comenv\}//sg ;
+    $cnt = 0 + $body =~ s/\\begin(?:\[${brat0}\])?\{${comenv}\}.*?\\end\{${comenv}\}\s*?\n//sg ;
+  print STDERR "$cnt matches found and removed.\n" if $verbose;
+  $body =~ s/(%.*)${someword}/$1${comenv}/mg ;
+}
+
+if (defined($markup)) {
+  print STDERR "Removing \\$markup\{..\} cpmmands ..." if $verbose;
+  # protect $markups in comments by making them look different
+  $body =~ s/(%.*)${markup}(.*)$/$1${someword}$2/mg ;
+  # carry out the substitution
+  $cnt = 0 + $body =~ s/\\${markup}(?:\[${brat0}\])?\{(${pat4})\}/$1/sg ;
+  print STDERR "$cnt matches found and removed.\n" if $verbose;
+  # and undo the protection substitution
+  $body =~ s/(%.*)${someword}(.*)$/$1${markup}$2/mg ;
+}
+if (defined($markenv)) {
+  print STDERR "Removing $markenv environments ..." if $verbose;
+  $body =~ s/(%.*)${markenv}/$1${someword}/mg ;
+  $cnt = 0 + $body =~ s/\\begin(?:\[${brat0}\])?\{${markenv}\}\n?//sg;
+  $cnt += 0 + $body =~ s/\\end\{${markenv}\}\n?//sg;
+  print STDERR $cnt/2, " matches found and removed.\n" if $verbose;
+  $body =~ s/(%.*)${someword}/$1${markenv}/mg ;
+}
+
+
+if ( length $preamble ) {
+  print "$preamble\\begin{document}${body}\\end{document}$post";
+} else {
+  print $body;
+}
+
+# checkpure(@matches)
+# checks whether any of the strings in matches contains
+# $ADDMARKOPEN, $ADDMARKCLOSE,$DELMARKOPEN, or $DELMARKCLOSE
+# If so, die reporting nesting problems, otherwise return to caller
+sub checkpure {
+  while (defined($_=shift)) {
+    if (  /$ADDMARKOPEN/ || /$ADDMARKCLOSE/
+	  || /$DELMARKOPEN/ || /$DELMARKCLOSE/ ) {
+      die <<EOF ;
+There is a problem with nesting of  $ADDMARKOPEN, $ADDMARKCLOSE,
+$DELMARKOPEN, and $DELMARKCLOSE tokens that prevents me from 
+processing the file.  Exiting ...
+EOF
+     }
+  }
+}
+
+# ($part1,$part2,$part3)=splitdoc($text,$word1,$word2)
+# splits $text into 3 parts at $word1 and $word2.
+# if neither $word1 nor $word2 exist, $part1 and $part3 are empty, $part2 is $text
+# If only $word1 or $word2 exist but not the other, output an error message.
+#
+# same subroutine as in latexdiff
+sub splitdoc {
+  my ($text,$word1,$word2)=@_;
+  my $l1 = length $word1 ;
+  my $l2 = length $word2 ;
+
+  my $i = index($text,$word1);
+  my $j = index($text,$word2);
+
+  my ($part1,$part2,$part3)=("","","");
+
+  if ( $i<0 && $j<0) {
+    # no $word1 or $word2
+    print STDERR "Old Document not a complete latex file. Assuming it is a tex file with no preamble.\n";
+    $part2 = $text;
+  } elsif ( $i>=0 && $j>$i ) {
+    $part1 = substr($text,0,$i) ; 
+    $part2 = substr($text,$i+$l1,$j-$i-$l1);
+    $part3 = substr($text,$j+$l2) unless $j+$l2 >= length $text;
+  } else {
+    die "$word1 or $word2 not in the correct order or not present as a pair."
+  }
+  return ($part1,$part2,$part3);
+}
+
+
+
+sub usage {
+  die <<"EOF"; 
+Usage: $0 [OPTIONS] [diff.tex] > revised.tex
+
+Read a file diff.tex (output of latexdiff), and remove its markup. 
+If no filename is given read from standard input. The command can be used
+in ACCEPT, DECLINE, or SIMPLIFY mode, and be used to remove user-defined
+latex commands from the input (see options -c, -e, -m, -n below). 
+In ACCEPT mode, all appended text fragments  (or preamble lines)
+are kept, and all discarded text fragments (or preamble lines) are
+deleted.  
+In DECLINE mode, all discarded text fragments are kept, and all appended 
+text fragments are deleted.  
+If you wish to keep some changes, edit the diff.tex file in
+advance, and manually remove those tokens  which would otherwise be
+deleted.  Note that latexrevise only pays attention to the \\DIFaddbegin,
+\\DIFaddend, \\DIFdelbegin, and \\DIFdelend tokens and corresponding FL
+varieties.  All \\DIFadd and \\DIFdel commands (but not their content) are 
+simply deleted.   The commands added by latexdiff to the preamble are also
+removed.
+In SIMPLIFY mode all latexdiff markup is removed from the body of the text (after
+\\begin{document}) except for \\DIFaddbegin, \\DIFaddend, \\DIFdelbegin, \\DIFdelend
+tokens and the corresponding FL varieties of those commands.  The result
+will not in general be valid latex-code but might be easier to read and edit in 
+preparation for a subsequent run in ACCEPT or DECLINE mode.  
+In SIMPLIFY mode the preamble is left unmodified.
+
+-a
+--accept          Run in ACCEPT mode (delete all blocks marked by \\DIFdelbegin
+                  and \\DIFdelend).
+
+-d
+--decline         Run in DECLINE mode (delete all blocks marked by \\DIFaddbegin
+                  and \\DIFaddend).
+
+-s
+--simplify        Run in SIMPLIFY mode (Keep all \\DIFaddbegin, \\DIFaddend, 
+                  \\DIFdelbegin, \\DIFdelend tokens, but remove all other latexdiff
+                  markup from body.  
+
+Note that the three mode options are mutually exclusive. If no mode option is given,
+latexrevise simply removes user annotations and markup according to the following four
+options.
+
+
+-c cmd
+--comment=cmd     Remove \\cmd{...}.  cmd is supposed to mark some explicit 
+                  anotations which should be removed from the file before 
+                  release.
+
+-e envir
+--comment-environment=envir 
+                  Remove explicit annotation environments from the text, i.e. remove
+                  \\begin{envir}
+                  ...
+                  \\end{envir}
+                  blocks.
+
+-m cmd
+--markup=cmd      Remove the markup command cmd but leave its argument, i.e.
+                  turn \\cmd{abc} into abc.  
+
+-n envir
+--markup-environment=envir  
+                  Similarly, remove \\begin{envir} and \\end{envir} commands,
+                  but leave content of the environment in the text.
+                  
+-q
+--no-warnings     Do not warn users about \\DIDadd{..} or \\DIFdel statements
+                  which should not be there anymore
+
+-V
+--verbose         Verbose output
+
+EOF
+}
+
+=head1 NAME
+
+latexrevise - selectively remove markup and text from latexdiff output
+
+=head1 SYNOPSIS
+
+B<latexrevise> [ B<OPTIONS> ] [ F<diff.tex> ] > F<revised.tex>
+
+=head1 DESCRIPTION
+
+I<latexrevise> reads a file C<diff.tex> (output of I<latexdiff>), and remove the markup commands. 
+If no filename is given the input is read from standard input. The command can be used
+in I<ACCEPT>, I<DECLINE>, or I<SIMPLIFY> mode, or can be used to remove user-defined
+latex commands from the input (see B<-c>, B<-e>, B<-m>, and B<-n> below). 
+In I<ACCEPT> mode, all appended text fragments  (or preamble lines)
+are kept, and all discarded text fragments (or preamble lines) are
+deleted.  
+In I<DECLINE> mode, all discarded text fragments are kept, and all appended 
+text fragments are deleted.  
+If you wish to keep some changes, edit the diff.tex file in
+advance, and manually remove those tokens  which would otherwise be
+deleted.  Note that I<latexrevise> only pays attention to the C<\DIFaddbegin>,
+C<\DIFaddend>, C<\DIFdelbegin>, and C<\DIFdelend> tokens and corresponding FL
+varieties.  All C<\DIFadd> and C<\DIFdel> commands (but not their contents) are 
+simply deleted.   The commands added by latexdiff to the preamble are also
+removed.
+In I<SIMPLIFY> mode, C<\DIFaddbegin, \DIFaddend, \DIFdelbegin, \DIFdelend>
+tokens and their corresponding C<FL> varieties are kept but all other markup (e.g. C<DIFadd> and <\DIFdel>) is removed.  The result
+will not in general be valid latex-code but it will be easier to read and edit in 
+preparation for a subsequent run in I<ACCEPT> or I<DECLINE> mode.  
+In I<SIMPLIFY> mode the preamble is left unmodified.
+
+=head1 OPTIONS
+
+=over 4
+
+=item B<-a> or B<--accept>
+
+Run in I<ACCEPT> mode (delete all blocks marked by C<\DIFdelbegin> and C<\DIFdelend>).
+
+=item B<-d> or B<--decline>
+
+Run in I<DECLINE> mode (delete all blocks marked by C<\DIFaddbegin>
+and C<\DIFaddend>).
+
+=item B<-s> or B<--simplify>
+
+Run in I<SIMPLIFY> mode (Keep all C<\DIFaddbegin>, C<\DIFaddend>, 
+C<\DIFdelbegin>, C<\DIFdelend> tokens, but remove all other latexdiff
+markup from body).  
+
+=back
+
+Note that the three mode options are mutually exclusive.  If no mode option is given,
+I<latexrevise> simply removes user annotations and markup according to the following four
+options.
+
+=over 4
+
+=item B<-c cmd> or B<--comment=cmd>
+
+Remove C<\cmd{...}> sequences.  C<cmd> is supposed to mark some explicit 
+anotations which should be removed from the file before 
+release.
+
+=item B<-e envir> or B<--comment-environment=envir> 
+
+Remove explicit annotation environments from the text, i.e. remove
+
+            \begin{envir}
+            ...
+            \end{envir}
+
+blocks.
+
+=item B<-m cmd> or B<--markup=cmd>
+
+Remove the markup command C<\cmd> but leave its argument, i.e.
+turn C<\cmd{abc}> into C<abc>.  
+
+=item B<-n envir> or B<--markup-environment=envir>
+
+Similarly, remove C<\begin{envir}> and C<\end{envir}> commands but 
+leave content of the environment in the text.
+                  
+
+=item B<-V> or B<--verbose>
+
+Verbose output
+
+=item B<-q> or B<--no-warnings>
+
+Do not warn users about C<\DIDadd{..}> or C<\DIFdel{..}> statements
+which should have been removed already.
+
+=back
+
+=head1 BUGS
+
+The current version is a beta version which has not yet been
+extensively tested, but worked fine locally.  Please send bug reports
+to I<tilmann@esc.cam.ac.uk>.  Include the serial number of I<latexrevise>
+(from comments at the top of the source).  If you come across latexdiff
+output which is not processed correctly by I<latexrevise> please include the
+problem file as well as the old and new files on which it is based,
+ideally edited to only contain the offending passage as long as that still
+reproduces the problem.
+
+I<latexrevise> gets confused by commented C<\begin{document}> or 
+C<\end{document}> statements
+
+=head1 SEE ALSO
+
+L<latexdiff>
+
+=head1 PORTABILITY
+
+I<latexrevise> does not make use of external commands and thus should run
+on any platform  supporting PERL v5 or higher. 
+
+=head1 AUTHOR
+
+Copyright (C) 2004 Frederik Tilmann
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License Version 2
+
+=cut
diff --git a/Master/texmf/doc/man/man1/latexdiff-vc.1 b/Master/texmf/doc/man/man1/latexdiff-vc.1
new file mode 100644
index 00000000000..1c5946d6fdf
--- /dev/null
+++ b/Master/texmf/doc/man/man1/latexdiff-vc.1
@@ -0,0 +1,235 @@
+.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14
+.\"
+.\" Standard preamble:
+.\" ========================================================================
+.de Sh \" Subsection heading
+.br
+.if t .Sp
+.ne 5
+.PP
+\fB\\$1\fR
+.PP
+..
+.de Sp \" Vertical space (when we can't use .PP)
+.if t .sp .5v
+.if n .sp
+..
+.de Vb \" Begin verbatim text
+.ft CW
+.nf
+.ne \\$1
+..
+.de Ve \" End verbatim text
+.ft R
+.fi
+..
+.\" Set up some character translations and predefined strings.  \*(-- will
+.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
+.\" double quote, and \*(R" will give a right double quote.  | will give a
+.\" real vertical bar.  \*(C+ will give a nicer C++.  Capital omega is used to
+.\" do unbreakable dashes and therefore won't be available.  \*(C` and \*(C'
+.\" expand to `' in nroff, nothing in troff, for use with C<>.
+.tr \(*W-|\(bv\*(Tr
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.ie n \{\
+.    ds -- \(*W-
+.    ds PI pi
+.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
+.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
+.    ds L" ""
+.    ds R" ""
+.    ds C` ""
+.    ds C' ""
+'br\}
+.el\{\
+.    ds -- \|\(em\|
+.    ds PI \(*p
+.    ds L" ``
+.    ds R" ''
+'br\}
+.\"
+.\" If the F register is turned on, we'll generate index entries on stderr for
+.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
+.\" entries marked with X<> in POD.  Of course, you'll have to process the
+.\" output yourself in some meaningful fashion.
+.if \nF \{\
+.    de IX
+.    tm Index:\\$1\t\\n%\t"\\$2"
+..
+.    nr % 0
+.    rr F
+.\}
+.\"
+.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
+.\" way too many mistakes in technical documents.
+.hy 0
+.if n .na
+.\"
+.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
+.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
+.    \" fudge factors for nroff and troff
+.if n \{\
+.    ds #H 0
+.    ds #V .8m
+.    ds #F .3m
+.    ds #[ \f1
+.    ds #] \fP
+.\}
+.if t \{\
+.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
+.    ds #V .6m
+.    ds #F 0
+.    ds #[ \&
+.    ds #] \&
+.\}
+.    \" simple accents for nroff and troff
+.if n \{\
+.    ds ' \&
+.    ds ` \&
+.    ds ^ \&
+.    ds , \&
+.    ds ~ ~
+.    ds /
+.\}
+.if t \{\
+.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
+.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
+.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
+.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
+.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
+.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
+.\}
+.    \" troff and (daisy-wheel) nroff accents
+.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
+.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
+.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
+.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
+.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
+.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
+.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
+.ds ae a\h'-(\w'a'u*4/10)'e
+.ds Ae A\h'-(\w'A'u*4/10)'E
+.    \" corrections for vroff
+.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
+.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
+.    \" for low resolution devices (crt and lpr)
+.if \n(.H>23 .if \n(.V>19 \
+\{\
+.    ds : e
+.    ds 8 ss
+.    ds o a
+.    ds d- d\h'-1'\(ga
+.    ds D- D\h'-1'\(hy
+.    ds th \o'bp'
+.    ds Th \o'LP'
+.    ds ae ae
+.    ds Ae AE
+.\}
+.rm #[ #] #H #V #F C
+.\" ========================================================================
+.\"
+.IX Title "LATEXDIFF-VC 1"
+.TH LATEXDIFF-VC 1 "2007-07-24" "perl v5.8.5" " "
+.SH "NAME"
+latexdiff\-vc \- wrapper script that calls latexdiff for different versions of a file under version management (CVS, RCS or SVN)
+.SH "SYNOPSIS"
+.IX Header "SYNOPSIS"
+\&\fBlatexdiff-vc\fR [ \fIlatexdiff-options\fR ] [ \fIlatexdiff-vc-options\fR ]  \fB\-r\fR [\fIrev1\fR] [\fB\-r\fR \fIrev2\fR]  \fIfile1.tex\fR [ \fIfile2.tex\fR ...]
+.PP
+.Vb 1
+\& or
+.Ve
+.PP
+\&\fBlatexdiff-vc\fR [ \fIlatexdiff-options\fR ]  [ \fIlatexdiff-vc-options\fR ][ \fB\-\-postscript\fR | \fB\-\-pdf\fR ]  \fIold.tex\fR \fInew.tex\fR
+.SH "DESCRIPTION"
+.IX Header "DESCRIPTION"
+\&\fIlatexdiff-vc\fR is a wrapper script that applies \fIlatexdiff\fR to a
+file, or multiple files under version control (\s-1CVS\s0 or \s-1RCS\s0), and optionally runs the
+sequence of \f(CW\*(C`latex\*(C'\fR and \f(CW\*(C`dvips\*(C'\fR or \f(CW\*(C`pdflatex\*(C'\fR commands necessary to
+produce pdf or postscript output of the difference tex file(s). It can
+also be applied to a pair of files to automatise the generation of difference
+file in postscript or pdf format.
+.SH "OPTIONS"
+.IX Header "OPTIONS"
+.IP "\fB\-\-rcs\fR, \fB\-\-svn\fR, or \fB\-\-cvs\fR" 4
+.IX Item "--rcs, --svn, or --cvs"
+Set the version system. 
+If no version system is specified, latexdiff-vc will venture a guess.
+.Sp
+latexdiff-cvs and latexdiff-rcs are variants of latexdiff-vc which default to 
+the respective versioning system. However, this default can still be overridden using the options above.
+.IP "\fB\-r\fR, \fB\-r\fR \fIrev\fR or \fB\-\-revision\fR, \fB\-\-revision=\fR\fIrev\fR" 4
+.IX Item "-r, -r rev or --revision, --revision=rev"
+Choose revision (under \s-1RCS\s0, \s-1CVS\s0 or \s-1SVN\s0). One or two \fB\-r\fR options can be
+specified, and the resulting in different behaviour:
+.RS 4
+.IP "\fBlatexdiff-vc\fR \-r \fIfile.tex\fR ..." 4
+.IX Item "latexdiff-vc -r file.tex ..."
+compares \fIfile.tex\fR with the most recent version checked into \s-1RCS\s0.
+.IP "\fBlatexdiff-vc\fR \-r \fIrev1\fR \fIfile.tex\fR ..." 4
+.IX Item "latexdiff-vc -r rev1 file.tex ..."
+compares \fIfile.tex\fR with revision \fIrev1\fR.
+.IP "\fBlatexdiff-vc\fR \-r \fIrev1\fR \-r \fIrev2\fR \fIfile.tex\fR ..." 4
+.IX Item "latexdiff-vc -r rev1 -r rev2 file.tex ..."
+compares revisions \fIrev1\fR and \fIrev2\fR of \fIfile.tex\fR.
+.Sp
+Multiple files can be specified for all of the above options. All files must have the
+extension \f(CW\*(C`.tex\*(C'\fR, though.
+.IP "\fBlatexdiff-vc\fR  \fIold.tex\fR \fInew.tex\fR" 4
+.IX Item "latexdiff-vc  old.tex new.tex"
+compares two files.
+.RE
+.RS 4
+.Sp
+The name of the difference file is generated automatically and
+reported to stdout.
+.RE
+.IP "\fB\-d\fR or \fB\-\-dir\fR  \fB\-d\fR \fIpath\fR or \fB\-\-dir=\fR\fIpath\fR" 4
+.IX Item "-d or --dir  -d path or --dir=path"
+Rather than appending the string \f(CW\*(C`diff\*(C'\fR and optionally the version
+numbers given to the output\-file, this will prepend a directory name \f(CW\*(C`diff\*(C'\fR 
+to the
+original filename, creating the directory and subdirectories should they not exist already.  This is particularly useful in order to clone a
+complete directory hierarchy.  Optionally, a pathname \fIpath\fR can be specified, which is prepended instead of \f(CW\*(C`diff\*(C'\fR.
+.IP "\fB\-\-ps\fR or \fB\-\-postscript\fR" 4
+.IX Item "--ps or --postscript"
+Generate postscript output from difference file.  This will run the
+sequence \f(CW\*(C`latex; latex; dvips\*(C'\fR on the difference file (do not use
+this option in the rare cases, where three \f(CW\*(C`latex\*(C'\fR commands are
+required if you care about correct referencing).  If the difference
+file contains a \f(CW\*(C`\ebibliography\*(C'\fR tag, run the sequence \f(CW\*(C`latex;
+bibtex; latex; latex; dvips\*(C'\fR.
+.IP "\fB\-\-pdf\fR" 4
+.IX Item "--pdf"
+Generate pdf output from difference file using \f(CW\*(C`pdflatex\*(C'\fR. This will
+run the sequence \f(CW\*(C`pdflatex; pdflatex\*(C'\fR on the difference file, or
+\&\f(CW\*(C`pdflatex; bibtex; pdflatex; pdflatex\*(C'\fR for files requiring bibtex.
+.IP "\fB\-\-force\fR" 4
+.IX Item "--force"
+Overwrite existing diff files without asking for confirmation. Default 
+behaviour is to ask for confirmation before overwriting an existing difference
+file.
+.IP "\fB\-\-help\fR or \fB\-h\fR" 4
+.IX Item "--help or -h"
+Show help text
+.IP "\fB\-\-version\fR" 4
+.IX Item "--version"
+Show version number
+.PP
+All other options are passed on to \f(CW\*(C`latexdiff\*(C'\fR.
+.SH "SEE ALSO"
+.IX Header "SEE ALSO"
+latexdiff
+.SH "PORTABILITY"
+.IX Header "PORTABILITY"
+\&\fIlatexdiff-vc\fR uses external commands and is therefore
+limited to Unix-like systems. It also requires the \s-1RCS\s0 version control
+system and latex to be installed on the system.  Modules from Perl 5.8
+or higher are required.
+.SH "AUTHOR"
+.IX Header "AUTHOR"
+Copyright (C) 2005 Frederik Tilmann
+.PP
+This program is free software; you can redistribute it and/or modify
+it under the terms of the \s-1GNU\s0 General Public License Version 2
+Contributors: S Utcke, H Bruyninckx
diff --git a/Master/texmf/doc/man/man1/latexdiff.1 b/Master/texmf/doc/man/man1/latexdiff.1
new file mode 100644
index 00000000000..7b6653fca4e
--- /dev/null
+++ b/Master/texmf/doc/man/man1/latexdiff.1
@@ -0,0 +1,666 @@
+.\" Automatically generated by Pod::Man v1.34, Pod::Parser v1.13
+.\"
+.\" Standard preamble:
+.\" ========================================================================
+.de Sh \" Subsection heading
+.br
+.if t .Sp
+.ne 5
+.PP
+\fB\\$1\fR
+.PP
+..
+.de Sp \" Vertical space (when we can't use .PP)
+.if t .sp .5v
+.if n .sp
+..
+.de Vb \" Begin verbatim text
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+.ne \\$1
+..
+.de Ve \" End verbatim text
+.ft R
+.fi
+..
+.\" Set up some character translations and predefined strings.  \*(-- will
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+.\" double quote, and \*(R" will give a right double quote.  | will give a
+.\" real vertical bar.  \*(C+ will give a nicer C++.  Capital omega is used to
+.\" do unbreakable dashes and therefore won't be available.  \*(C` and \*(C'
+.\" expand to `' in nroff, nothing in troff, for use with C<>.
+.tr \(*W-|\(bv\*(Tr
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.ie n \{\
+.    ds -- \(*W-
+.    ds PI pi
+.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
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+.    ds L" ""
+.    ds R" ""
+.    ds C` ""
+.    ds C' ""
+'br\}
+.el\{\
+.    ds -- \|\(em\|
+.    ds PI \(*p
+.    ds L" ``
+.    ds R" ''
+'br\}
+.\"
+.\" If the F register is turned on, we'll generate index entries on stderr for
+.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
+.\" entries marked with X<> in POD.  Of course, you'll have to process the
+.\" output yourself in some meaningful fashion.
+.if \nF \{\
+.    de IX
+.    tm Index:\\$1\t\\n%\t"\\$2"
+..
+.    nr % 0
+.    rr F
+.\}
+.\"
+.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
+.\" way too many mistakes in technical documents.
+.hy 0
+.if n .na
+.\"
+.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
+.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
+.    \" fudge factors for nroff and troff
+.if n \{\
+.    ds #H 0
+.    ds #V .8m
+.    ds #F .3m
+.    ds #[ \f1
+.    ds #] \fP
+.\}
+.if t \{\
+.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
+.    ds #V .6m
+.    ds #F 0
+.    ds #[ \&
+.    ds #] \&
+.\}
+.    \" simple accents for nroff and troff
+.if n \{\
+.    ds ' \&
+.    ds ` \&
+.    ds ^ \&
+.    ds , \&
+.    ds ~ ~
+.    ds /
+.\}
+.if t \{\
+.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
+.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
+.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
+.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
+.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
+.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
+.\}
+.    \" troff and (daisy-wheel) nroff accents
+.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
+.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
+.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
+.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
+.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
+.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
+.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
+.ds ae a\h'-(\w'a'u*4/10)'e
+.ds Ae A\h'-(\w'A'u*4/10)'E
+.    \" corrections for vroff
+.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
+.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
+.    \" for low resolution devices (crt and lpr)
+.if \n(.H>23 .if \n(.V>19 \
+\{\
+.    ds : e
+.    ds 8 ss
+.    ds o a
+.    ds d- d\h'-1'\(ga
+.    ds D- D\h'-1'\(hy
+.    ds th \o'bp'
+.    ds Th \o'LP'
+.    ds ae ae
+.    ds Ae AE
+.\}
+.rm #[ #] #H #V #F C
+.\" ========================================================================
+.\"
+.IX Title "LATEXDIFF 1"
+.TH LATEXDIFF 1 "2007-10-19" "perl v5.8.0" " "
+.SH "NAME"
+latexdiff \- determine and markup differences between two latex files
+.SH "SYNOPSIS"
+.IX Header "SYNOPSIS"
+\&\fBlatexdiff\fR [ \fB\s-1OPTIONS\s0\fR ] \fIold.tex\fR \fInew.tex\fR > \fIdiff.tex\fR
+.SH "DESCRIPTION"
+.IX Header "DESCRIPTION"
+Briefly, \fIlatexdiff\fR is a utility program to aid in the management of
+revisions of latex documents. It compares two valid latex files, here
+called \f(CW\*(C`old.tex\*(C'\fR and \f(CW\*(C`new.tex\*(C'\fR, finds significant differences
+between them (i.e., ignoring the number of white spaces and position
+of line breaks), and adds special commands to highlight the
+differences.  Where visual highlighting is not possible, e.g. for changes
+in the formatting, the differences are
+nevertheless marked up in the source.
+.PP
+The program treats the preamble differently from the main document.
+Differences between the preambles are found using line-based
+differencing (similarly to the Unix diff command, but ignoring white
+spaces).  A comment, "\f(CW\*(C`%DIF\ >\*(C'\fR" is appended to each added line, i.e. a 
+line present in \f(CW\*(C`new.tex\*(C'\fR but not in \f(CW\*(C`old.tex\*(C'\fR.  Discarded lines 
+ are deactivated by prepending "\f(CW\*(C`%DIF\ <\*(C'\fR". Changed blocks are preceded  by
+comment lines giving information about line numbers in the original files.  Where there are insignificant
+differences, the resulting file \f(CW\*(C`diff.tex\*(C'\fR will be similar to
+\&\f(CW\*(C`new.tex\*(C'\fR.  At the end of the preamble, the definitions for \fIlatexdiff\fR markup commands are inserted.
+In differencing the main body of the text, \fIlatexdiff\fR attempts to
+satisfy the following guidelines (in order of priority):
+.IP "1" 3
+.IX Item "1"
+If both \f(CW\*(C`old.tex\*(C'\fR and \f(CW\*(C`new.tex\*(C'\fR are valid LaTeX, then the resulting
+\&\f(CW\*(C`diff.tex\*(C'\fR should also be valid LateX. (\s-1NB\s0 If a few plain TeX commands
+are used within \f(CW\*(C`old.tex\*(C'\fR or \f(CW\*(C`new.tex\*(C'\fR then \f(CW\*(C`diff.tex\*(C'\fR is not
+guaranteed to work but usually will).
+.IP "2" 3
+.IX Item "2"
+Significant differences are determined on the level of
+individual words. All significant differences, including differences
+between comments should be clearly marked in the resulting source code
+\&\f(CW\*(C`diff.tex\*(C'\fR.
+.IP "3" 3
+.IX Item "3"
+If a changed passage contains text or text-producing commands, then
+running \f(CW\*(C`diff.tex\*(C'\fR through LateX should produce output where added
+and discarded passages are highlighted.
+.IP "4" 3
+.IX Item "4"
+Where there are insignificant differences, e.g. in the positioning of
+line breaks, \f(CW\*(C`diff.tex\*(C'\fR should follow the formatting of \f(CW\*(C`new.tex\*(C'\fR
+.PP
+For differencing the same algorithm as \fIdiff\fR is used but words
+instead of lines are compared.  An attempt is made to recognize
+blocks which are completely changed such that they can be marked up as a unit.
+Comments are differenced line by line
+but the number of spaces within comments is ignored. Commands including
+all their arguments are generally compared as one unit, i.e., no mark-up
+is inserted into the arguments of commands.  However, for a selected
+number of commands (for example, \f(CW\*(C`\ecaption\*(C'\fR and all sectioning
+commands) the last argument is known to be text. This text is
+split into words and differenced just as ordinary text (use options to
+show and change the list of text commands, see below). As the
+algorithm has no detailed knowledge of LaTeX, it assumes all pairs of
+curly braces immediately following a command (i.e. a sequence of
+letters beginning with a backslash) are arguments for that command.
+As a restriction to condition 1 above it is thus necessary to surround
+all arguments with curly braces, and to not insert
+extraneous spaces.  For example, write 
+.PP
+.Vb 1
+\&  \esection{\etextem{This is an emphasized section title}}
+.Ve
+.PP
+and not
+.PP
+.Vb 1
+\&  \esection {\etextem{This is an emphasized section title}}
+.Ve
+.PP
+or
+.PP
+.Vb 1
+\&  \esection\etextem{This is an emphasized section title}
+.Ve
+.PP
+even though all varieties are the same to LaTeX (but see
+\&\fB\-\-allow\-spaces\fR option which allows the second variety).
+.PP
+For environments whose content does not conform to standard LaTeX or
+where graphical markup does not make sense all markup commands can be
+removed by setting the \s-1PICTUREENV\s0 configuration variable, set by
+default to \f(CW\*(C`picture\*(C'\fR and \f(CW\*(C`DIFnomarkup\*(C'\fR environments; see \fB\-\-config\fR
+option).  The latter environment (\f(CW\*(C`DIFnomarkup\*(C'\fR) can be used to
+protect parts of the latex file where the markup results in illegal
+markup. You have to surround the offending passage in both the old and
+new file by \f(CW\*(C`\ebegin{DIFnomarkup}\*(C'\fR and \f(CW\*(C`\eend{DIFnomarkup}\*(C'\fR. You must
+define the environment in the preambles of both old and new
+documents. I prefer to define it as a null\-environment,
+.PP
+\&\f(CW\*(C`\enewenvironment{DIFnomarkup}{}{}\*(C'\fR
+.PP
+but the choice is yours.  Any markup within the environment will be
+removed, and generally everything within the environment will just be
+taken from the new file.
+.PP
+It is also possible to difference files which do not have a preamble. 
+ In this case, the file is processed in the main document
+mode, but the definitions of the markup commands are not inserted.
+.PP
+All markup commands inserted by \fIlatexdiff\fR begin with "\f(CW\*(C`\eDIF\*(C'\fR".  Added
+blocks containing words, commands or comments which are in \f(CW\*(C`new.tex\*(C'\fR
+but not in \f(CW\*(C`old.tex\*(C'\fR are marked by \f(CW\*(C`\eDIFaddbegin\*(C'\fR and \f(CW\*(C`\eDIFaddend\*(C'\fR.
+Discarded blocks are marked by \f(CW\*(C`\eDIFdelbegin\*(C'\fR and \f(CW\*(C`\eDIFdelend\*(C'\fR.
+Within added blocks all text is highlighted with \f(CW\*(C`\eDIFadd\*(C'\fR like this:
+\&\f(CW\*(C`\eDIFadd{Added text block}\*(C'\fR
+Selected `safe' commands can be contained in these text blocks as well
+(use options to show and change the list of safe commands, see below).
+All other commands as well as braces \*(L"{\*(R" and \*(L"}\*(R" are never put within
+the scope of \f(CW\*(C`\eDIFadd\*(C'\fR.  Added comments are marked by prepending
+"\f(CW\*(C`%DIF\ >\ \*(C'\fR".
+.PP
+Within deleted blocks text is highlighted with \f(CW\*(C`\eDIFdel\*(C'\fR.  Deleted
+comments are marked by prepending "\f(CW\*(C`%DIF\ <\ \*(C'\fR\*(L".  Non-safe command
+and curly braces within deleted blocks are commented out with 
+\&\*(R"\f(CW\*(C`%DIFDELCMD\ <\ \*(C'\fR".
+.SH "OPTIONS"
+.IX Header "OPTIONS"
+.Sh "Preamble"
+.IX Subsection "Preamble"
+The following options determine the visual markup style by adding the appropriate
+command definitions to the preamble. See the end of this section for a description of 
+available styles.
+.IP "\fB\-\-type=markupstyle\fR or \fB\-t markupstyle\fR" 4
+.IX Item "--type=markupstyle or -t markupstyle"
+Add code to preamble for selected markup style. This option defines
+\&\f(CW\*(C`\eDIFadd\*(C'\fR and \f(CW\*(C`\eDIFdel\*(C'\fR commands.
+Available styles: 
+.Sp
+\&\f(CW\*(C`UNDERLINE CTRADITIONAL TRADITIONAL CFONT FONTSTRIKE INVISIBLE 
+CHANGEBAR CCHANGEBAR CULINECHBAR CFONTCBHBAR\*(C'\fR
+.Sp
+[ Default: \f(CW\*(C`UNDERLINE\*(C'\fR ]
+.IP "\fB\-\-subtype=markstyle\fR or \fB\-s markstyle\fR" 4
+.IX Item "--subtype=markstyle or -s markstyle"
+Add code to preamble for selected style for bracketing
+commands (e.g. to mark changes in  margin). This option defines
+\&\f(CW\*(C`\eDIFaddbegin\*(C'\fR, \f(CW\*(C`\eDIFaddend\*(C'\fR, \f(CW\*(C`\eDIFdelbegin\*(C'\fR and \f(CW\*(C`\eDIFdelend\*(C'\fR commands.
+Available styles: \f(CW\*(C`SAFE MARGINAL DVIPSCOL\*(C'\fR
+.Sp
+[ Default: \f(CW\*(C`SAFE\*(C'\fR ]
+.IP "\fB\-\-floattype=markstyle\fR or \fB\-f markstyle\fR" 4
+.IX Item "--floattype=markstyle or -f markstyle"
+Add code to preamble for selected style which 
+replace standard marking and markup commands within floats
+(e.g., marginal remarks cause an error within floats
+so marginal marking can be disabled thus). This option defines all 
+\&\f(CW\*(C`\eDIF...FL\*(C'\fR commands.
+Available styles: \f(CW\*(C`FLOATSAFE TRADITIONALSAFE IDENTICAL\*(C'\fR
+.Sp
+[ Default: \f(CW\*(C`FLOATSAFE\*(C'\fR ]
+.IP "\fB\-\-encoding=enc\fR or \fB\-e enc\fR" 4
+.IX Item "--encoding=enc or -e enc"
+Specify encoding of old.tex and new.tex. Typical encodings are
+\&\f(CW\*(C`ascii\*(C'\fR, \f(CW\*(C`utf8\*(C'\fR, \f(CW\*(C`latin1\*(C'\fR, \f(CW\*(C`latin9\*(C'\fR.  A list of available encodings can be 
+obtained by executing 
+.Sp
+\&\f(CW\*(C`perl \-MEncode \-e 'print join ("\en",Encode\-\*(C'\fRencodings( \*(L":all\*(R" )) ;' >
+.Sp
+[Default encoding is utf8 unless the first few lines of the preamble contain
+an invocation \f(CW\*(C`\eusepackage[..]{inputenc}\*(C'\fR in which case the 
+encoding chosen by this command is asssumed. Note that \s-1ASCII\s0 (standard
+latex) is a subset of utf8]
+.IP "\fB\-\-preamble=file\fR or \fB\-p file\fR" 4
+.IX Item "--preamble=file or -p file"
+Insert file at end of preamble instead of generating
+preamble.  The preamble must define the following commands
+\&\f(CW\*(C`\eDIFaddbegin, \eDIFaddend, \eDIFadd{..},
+\&\eDIFdelbegin,\eDIFdelend,\eDIFdel{..},\*(C'\fR
+and varieties for use within floats
+\&\f(CW\*(C`\eDIFaddbeginFL, \eDIFaddendFL, \eDIFaddFL{..},
+\&\eDIFdelbeginFL, \eDIFdelendFL, \eDIFdelFL{..}\*(C'\fR
+(If this option is set \fB\-t\fR, \fB\-s\fR, and \fB\-f\fR options
+are ignored.)
+.IP "\fB\-\-packages=pkg1,pkg2,..\fR" 4
+.IX Item "--packages=pkg1,pkg2,.."
+Tell latexdiff that .tex file is processed with the packages in list
+loaded.  This is normally not necessary if the .tex file includes the
+preamble, as the preamble is automatically scanned for \f(CW\*(C`\eusepackage\*(C'\fR commands.
+Use of the \fB\-\-packages\fR option disables automatic scanning, so if for any
+reason package specific parsing needs to be switched off, use \fB\-\-packages=none\fR.
+The following packages trigger special behaviour:
+.RS 4
+.ie n .IP """amsmath""" 8
+.el .IP "\f(CWamsmath\fR" 8
+.IX Item "amsmath"
+Configuration variable amsmath is set to \f(CW\*(C`align*\*(C'\fR (Default: \f(CW\*(C`eqnarray*\*(C'\fR)
+.ie n .IP """endfloat""" 8
+.el .IP "\f(CWendfloat\fR" 8
+.IX Item "endfloat"
+Ensure that \f(CW\*(C`\ebegin{figure}\*(C'\fR and \f(CW\*(C`\eend{figure}\*(C'\fR always appear by themselves on a line.
+.ie n .IP """hyperref""" 8
+.el .IP "\f(CWhyperref\fR" 8
+.IX Item "hyperref"
+Change name of \f(CW\*(C`\eDIFadd\*(C'\fR and \f(CW\*(C`\eDIFdel\*(C'\fR commands to \f(CW\*(C`\eDIFaddtex\*(C'\fR and \f(CW\*(C`\eDIFdeltex\*(C'\fR and 
+define new \f(CW\*(C`\eDIFadd\*(C'\fR and \f(CW\*(C`\eDIFdel\*(C'\fR commands, which provide a wrapper for these commands,
+using them for the text but not for the link defining command (where any markup would cause
+errors).
+.RE
+.RS 4
+.Sp
+[ Default: scan the preamble for \f(CW\*(C`\e\eusepackage\*(C'\fR commands to determine
+  loaded packages.]
+.RE
+.IP "\fB\-\-show\-preamble\fR" 4
+.IX Item "--show-preamble"
+Print generated or included preamble commands to stdout.
+.Sh "Configuration"
+.IX Subsection "Configuration"
+.ie n .IP "\fB\-\-exclude\-safecmd=exclude\-file\fR or \fB\-A exclude-file\fR or  \fB\-\-exclude\-safecmd=""cmd1,cmd2,...""\fR" 4
+.el .IP "\fB\-\-exclude\-safecmd=exclude\-file\fR or \fB\-A exclude-file\fR or  \fB\-\-exclude\-safecmd=``cmd1,cmd2,...''\fR" 4
+.IX Item "--exclude-safecmd=exclude-file or -A exclude-file or  --exclude-safecmd=cmd1,cmd2,..."
+.PD 0
+.IP "\fB\-\-replace\-safecmd=replace\-file\fR" 4
+.IX Item "--replace-safecmd=replace-file"
+.ie n .IP "\fB\-\-append\-safecmd=append\-file\fR or \fB\-a append-file\fR or \fB\-\-append\-safecmd=""cmd1,cmd2,...""\fR" 4
+.el .IP "\fB\-\-append\-safecmd=append\-file\fR or \fB\-a append-file\fR or \fB\-\-append\-safecmd=``cmd1,cmd2,...''\fR" 4
+.IX Item "--append-safecmd=append-file or -a append-file or --append-safecmd=cmd1,cmd2,..."
+.PD
+Exclude from, replace or append to the list of regular expressions (RegEx)
+matching commands which are safe to use within the 
+scope of a \f(CW\*(C`\eDIFadd\*(C'\fR or \f(CW\*(C`\eDIFdel\*(C'\fR command.  The file must contain
+one Perl-RegEx per line (Comment lines beginning with # or % are
+ignored).  Note that the RegEx needs to match the whole of 
+the token, i.e., /^regex$/ is implied and that the initial
+\&\*(L"\e\*(R" of the command is not included. 
+The \fB\-\-exclude\-safecmd\fR and \fB\-\-append\-safecmd\fR options can be combined with the \-\fB\-\-replace\-safecmd\fR 
+option and can be used repeatedly to add cumulatively to the lists.
+ \fB\-\-exclude\-safecmd\fR
+and \fB\-\-append\-safecmd\fR can also take a comma separated list as input. If a
+comma for one of the regex is required, escape it thus \*(L"\e,\*(R". In most cases it
+will be necessary to protect the comma-separated list from the shell by putting
+it in quotation marks.
+.ie n .IP "\fB\-\-exclude\-textcmd=exclude\-file\fR or \fB\-X exclude-file\fR or \fB\-\-exclude\-textcmd=""cmd1,cmd2,...""\fR" 4
+.el .IP "\fB\-\-exclude\-textcmd=exclude\-file\fR or \fB\-X exclude-file\fR or \fB\-\-exclude\-textcmd=``cmd1,cmd2,...''\fR" 4
+.IX Item "--exclude-textcmd=exclude-file or -X exclude-file or --exclude-textcmd=cmd1,cmd2,..."
+.PD 0
+.IP "\fB\-\-replace\-textcmd=replace\-file\fR" 4
+.IX Item "--replace-textcmd=replace-file"
+.ie n .IP "\fB\-\-append\-textcmd=append\-file\fR or \fB\-x append-file\fR or \fB\-\-append\-textcmd=""cmd1,cmd2,...""\fR" 4
+.el .IP "\fB\-\-append\-textcmd=append\-file\fR or \fB\-x append-file\fR or \fB\-\-append\-textcmd=``cmd1,cmd2,...''\fR" 4
+.IX Item "--append-textcmd=append-file or -x append-file or --append-textcmd=cmd1,cmd2,..."
+.PD
+Exclude from, replace or append to the list of regular expressions
+matching commands whose last argument is text.  See
+entry for \fB\-\-exclude\-safecmd\fR directly above for further details.
+.IP "\fB\-\-replace\-context1cmd=replace\-file\fR" 4
+.IX Item "--replace-context1cmd=replace-file"
+.PD 0
+.ie n .IP "\fB\-\-append\-context1cmd=append\-file\fR or =item \fB\-\-append\-context1cmd=""cmd1,cmd2,...""\fR" 4
+.el .IP "\fB\-\-append\-context1cmd=append\-file\fR or =item \fB\-\-append\-context1cmd=``cmd1,cmd2,...''\fR" 4
+.IX Item "--append-context1cmd=append-file or =item --append-context1cmd=cmd1,cmd2,..."
+.PD
+Replace or append to the list of regex matching commands
+whose last argument is text but which require a particular
+context to work, e.g. \ecaption will only work within a figure
+or table.  These commands behave like text commands, except when 
+they occur in a deleted section, when they are disabled, but their
+argument is shown as deleted text.
+.IP "\fB\-\-replace\-context1cmd=replace\-file\fR" 4
+.IX Item "--replace-context1cmd=replace-file"
+.PD 0
+.ie n .IP "\fB\-\-append\-context2cmd=append\-file\fR or =item \fB\-\-append\-context2cmd=""cmd1,cmd2,...""\fR As corresponding commands for context1.  The only difference is that context2 commands are completely disabled in deleted sections, including their arguments." 4
+.el .IP "\fB\-\-append\-context2cmd=append\-file\fR or =item \fB\-\-append\-context2cmd=``cmd1,cmd2,...''\fR As corresponding commands for context1.  The only difference is that context2 commands are completely disabled in deleted sections, including their arguments." 4
+.IX Item "--append-context2cmd=append-file or =item --append-context2cmd=cmd1,cmd2,... As corresponding commands for context1.  The only difference is that context2 commands are completely disabled in deleted sections, including their arguments."
+.IP "\fB\-\-config var1=val1,var2=val2,...\fR or \fB\-c var1=val1,..\fR" 4
+.IX Item "--config var1=val1,var2=val2,... or -c var1=val1,.."
+.IP "\fB\-c configfile\fR" 4
+.IX Item "-c configfile"
+.PD
+Set configuration variables.  The option can be repeated to set different
+variables (as an alternative to the comma-separated list).
+Available variables (see below for further explanations): 
+.Sp
+\&\f(CW\*(C`MINWORDSBLOCK\*(C'\fR (integer)
+.Sp
+\&\f(CW\*(C`FLOATENV\*(C'\fR (RegEx)
+.Sp
+\&\f(CW\*(C`PICTUREENV\*(C'\fR (RegEx)
+.Sp
+\&\f(CW\*(C`MATHENV\*(C'\fR (RegEx)
+.Sp
+\&\f(CW\*(C`MATHREPL\*(C'\fR (String)
+.Sp
+\&\f(CW\*(C`MATHARRENV\*(C'\fR (RegEx)
+.Sp
+\&\f(CW\*(C`MATHARRREPL\*(C'\fR (String)
+.Sp
+\&\f(CW\*(C`ARRENV\*(C'\fR (RegEx)
+.Sp
+\&\f(CW\*(C`COUNTERCMD\*(C'\fR (RegEx)
+.IP "\fB\-\-show\-safecmd\fR" 4
+.IX Item "--show-safecmd"
+Print list of RegEx matching and excluding safe commands.
+.IP "\fB\-\-show\-textcmd\fR" 4
+.IX Item "--show-textcmd"
+Print list of RegEx matching and excluding commands with text argument.
+.IP "\fB\-\-show\-config\fR" 4
+.IX Item "--show-config"
+Show values of configuration variables.
+.IP "\fB\-\-show\-all\fR" 4
+.IX Item "--show-all"
+Combine all \-\-show commands.
+.Sp
+\&\s-1NB\s0 For all \-\-show commands, no \f(CW\*(C`old.tex\*(C'\fR or \f(CW\*(C`new.tex\*(C'\fR file needs to be specified, and no 
+differencing takes place.
+.Sh "Miscellaneous"
+.IX Subsection "Miscellaneous"
+.IP "\fB\-\-verbose\fR or \fB\-V\fR" 4
+.IX Item "--verbose or -V"
+Output various status information to stderr during processing.
+Default is to work silently.
+.IP "\fB\-\-ignore\-warnings\fR" 4
+.IX Item "--ignore-warnings"
+Suppress warnings about inconsistencies in length between input and
+parsed strings and missing characters.  These warning messages are
+often related to non-standard latex or latex constructions with a
+syntax unknown to \f(CW\*(C`latexdiff\*(C'\fR but the resulting difference argument
+is often fully functional anyway, particularly if the non-standard
+latex only occurs in parts of the text which have not changed.
+.IP "\fB\-\-allow\-spaces\fR" 4
+.IX Item "--allow-spaces"
+Allow spaces between bracketed or braced arguments to commands.  Note
+that this option might have undesirable side effects (unrelated scope
+might get lumpeded with preceding commands) so should only be used if the
+default produces erroneous results.  (Default requires arguments to
+directly follow each other without intervening spaces).
+.IP "\fB\-\-flatten\fR" 4
+.IX Item "--flatten"
+Replace \f(CW\*(C`\einput\*(C'\fR and \f(CW\*(C`\einclude\*(C'\fR commands within body by the content
+of the files in their argument.  If \f(CW\*(C`\eincludeonly\*(C'\fR is present in the
+preamble, only those files are expanded into the document. However, 
+no recursion is done, i.e. \f(CW\*(C`\einput\*(C'\fR and \f(CW\*(C`\einclude\*(C'\fR commands within 
+included sections are not expanded.  The included files are assumed to 
+ be located in the same directories as the old and new master files,
+respectively, making it possible to organise files into old and new directories. 
+.Sp
+Use of this option is not recommended
+primarily the processing time for the large documents is prohibitive, and
+the resulting difference document no longer reflects the structure of the 
+input documents. 
+.IP "\fB\-\-help\fR or \fB\-h\fR" 4
+.IX Item "--help or -h"
+Show help text
+.IP "\fB\-\-version\fR" 4
+.IX Item "--version"
+Show version number
+.Sh "Predefined styles"
+.IX Subsection "Predefined styles"
+.Sh "Major types"
+.IX Subsection "Major types"
+The major type determine the markup of plain text and some selected latex commands outside floats by defining the markup commands \f(CW\*(C`\eDIFadd{...}\*(C'\fR and \f(CW\*(C`\eDIFdel{...}\*(C'\fR .
+.ie n .IP """UNDERLINE""" 10
+.el .IP "\f(CWUNDERLINE\fR" 10
+.IX Item "UNDERLINE"
+Added text is wavy-underlined and blue, discarded text is struck out and red
+(Requires color and ulem packages).  Overstriking does not work in displayed math equations such that deleted parts of equation are underlined, not struck out (this is a shortcoming inherent to the ulem package).
+.ie n .IP """CTRADITIONAL""" 10
+.el .IP "\f(CWCTRADITIONAL\fR" 10
+.IX Item "CTRADITIONAL"
+Added text is blue and set in sans\-serif, and a red footnote is created for each discarded 
+piece of text. (Requires color package)
+.ie n .IP """TRADITIONAL""" 10
+.el .IP "\f(CWTRADITIONAL\fR" 10
+.IX Item "TRADITIONAL"
+Like \f(CW\*(C`CTRADITIONAL\*(C'\fR but without the use of color.
+.ie n .IP """CFONT""" 10
+.el .IP "\f(CWCFONT\fR" 10
+.IX Item "CFONT"
+Added text is blue and set in sans\-serif, and discarded text is red and very small size.
+.ie n .IP """FONTSTRIKE""" 10
+.el .IP "\f(CWFONTSTRIKE\fR" 10
+.IX Item "FONTSTRIKE"
+Added tex is set in sans\-serif, discarded text small and struck out
+.ie n .IP """CCHANGEBAR""" 10
+.el .IP "\f(CWCCHANGEBAR\fR" 10
+.IX Item "CCHANGEBAR"
+Added text is blue, and discarded text is red.  Additionally, the changed text is marked with a bar in the margin (Requires color and changebar packages).
+.ie n .IP """CFONTCHBAR""" 10
+.el .IP "\f(CWCFONTCHBAR\fR" 10
+.IX Item "CFONTCHBAR"
+Like \f(CW\*(C`CFONT\*(C'\fR but with additional changebars (Requires color and changebar packages).
+.ie n .IP """CULINECHBAR""" 10
+.el .IP "\f(CWCULINECHBAR\fR" 10
+.IX Item "CULINECHBAR"
+Like \f(CW\*(C`UNDERLINE\*(C'\fR but with additional changebars (Requires color, ulem and changebar packages).
+.ie n .IP """CHANGEBAR""" 10
+.el .IP "\f(CWCHANGEBAR\fR" 10
+.IX Item "CHANGEBAR"
+No mark up of text, but mark margins with changebars (Requires changebar package).
+.ie n .IP """INVISIBLE""" 10
+.el .IP "\f(CWINVISIBLE\fR" 10
+.IX Item "INVISIBLE"
+No visible markup (but generic markup commands will still be inserted.
+.Sh "Subtypes"
+.IX Subsection "Subtypes"
+The subtype defines the commands that are inserted at the begin and end of added or discarded blocks, irrespectively of whether these blocks contain text or commands (Defined commands: \f(CW\*(C`\eDIFaddbegin, \eDIFaddend, \eDIFdelbegin, \eDIFdelend\*(C'\fR) 
+.ie n .IP """SAFE""" 10
+.el .IP "\f(CWSAFE\fR" 10
+.IX Item "SAFE"
+No additional markup (Recommended choice)
+.ie n .IP """MARGIN""" 10
+.el .IP "\f(CWMARGIN\fR" 10
+.IX Item "MARGIN"
+Mark beginning and end of changed blocks with symbols in the margin nearby (using
+the standard \f(CW\*(C`\emarginpar\*(C'\fR command \- note that this sometimes moves somewhat
+from the intended position.
+.ie n .IP """DVIPSCOL""" 10
+.el .IP "\f(CWDVIPSCOL\fR" 10
+.IX Item "DVIPSCOL"
+An alternative way of marking added passages in blue, and deleted ones in red. Note
+that \f(CW\*(C`DVIPSCOL\*(C'\fR only works with the dvips converter, e.g. not pdflatex.
+(it is recommeneded to use instead the main types to effect colored markup,
+although in some cases coloring with dvipscol can be more complete).
+.Sh "Float Types"
+.IX Subsection "Float Types"
+Some of the markup used in the main text might cause problems when used within 
+floats (e.g. figures or tables).  For this reason alternative versions of all
+markup commands are used within floats. The float type defines these alternative commands.
+.ie n .IP """FLOATSAFE""" 10
+.el .IP "\f(CWFLOATSAFE\fR" 10
+.IX Item "FLOATSAFE"
+Use identical markup for text as in the main body, but set all commands marking the begin and end of changed blocks to null\-commands.  You have to choose this float type if your subtype is \f(CW\*(C`MARGIN\*(C'\fR as \f(CW\*(C`\emarginpar\*(C'\fR does not work properly within floats.
+.ie n .IP """TRADITIONALSAFE""" 10
+.el .IP "\f(CWTRADITIONALSAFE\fR" 10
+.IX Item "TRADITIONALSAFE"
+Mark additions the same way as in the main text.  Deleted environments are marked by angular brackets \e[ and \e] and the deleted text is set in scriptscript size. This float type should always be used with the \f(CW\*(C`TRADITIONAL\*(C'\fR and  \f(CW\*(C`CTRADITIONAL\*(C'\fR markup types as the \efootnote command does not work properly in floating environments.
+.ie n .IP """IDENTICAL""" 10
+.el .IP "\f(CWIDENTICAL\fR" 10
+.IX Item "IDENTICAL"
+Make no difference between the main text and floats.
+.Sh "Configuration Variables"
+.IX Subsection "Configuration Variables"
+.ie n .IP """MINWORDSBLOCK""" 10
+.el .IP "\f(CWMINWORDSBLOCK\fR" 10
+.IX Item "MINWORDSBLOCK"
+Minimum number of tokens required to form an independent block. This value is
+used in the algorithm to detect changes of complete blocks by merging identical text parts of less than \f(CW\*(C`MINWORDSBLOCK\*(C'\fR to the preceding added and discarded parts.
+.Sp
+[ Default: 3 ]
+.ie n .IP """FLOATENV""" 10
+.el .IP "\f(CWFLOATENV\fR" 10
+.IX Item "FLOATENV"
+Environments whose name matches the regular expression in \f(CW\*(C`FLOATENV\*(C'\fR are 
+considered floats.  Within these environments, the \fIlatexdiff\fR markup commands
+are replaced by their \s-1FL\s0 variaties.
+.Sp
+[ Default: \f(CW\*(C`(?:figure|table|plate)[\ew\ed*@]*\*(C'\fR\ ]
+.ie n .IP """PICTUREENV""" 10
+.el .IP "\f(CWPICTUREENV\fR" 10
+.IX Item "PICTUREENV"
+Within environments whose name matches the regular expression in \f(CW\*(C`PICTUREENV\*(C'\fR
+all latexdiff markup is removed (in pathologic cases this might lead to
+ inconsistent markup but this situation should be rare).
+.Sp
+[ Default: \f(CW\*(C`(?:picture|DIFnomarkup)[\ew\ed*@]*\*(C'\fR\ ]
+.ie n .IP """MATHENV""\fR,\f(CW""MATHREPL""" 10
+.el .IP "\f(CWMATHENV\fR,\f(CWMATHREPL\fR" 10
+.IX Item "MATHENV,MATHREPL"
+If both \ebegin and \eend for a math environment (environment name matching \f(CW\*(C`MATHENV\*(C'\fR
+or \e[ and \e])
+are within the same deleted block, they are replaced by a \ebegin and \eend commands for \f(CW\*(C`MATHREPL\*(C'\fR
+rather than being commented out.
+.Sp
+[ Default: \f(CW\*(C`MATHENV\*(C'\fR=\f(CW\*(C`(?:displaymath|equation)\*(C'\fR\ , \f(CW\*(C`MATHREPL\*(C'\fR=\f(CW\*(C`displaymath\*(C'\fR\ ]
+.ie n .IP """MATHARRENV""\fR,\f(CW""MATHARRREPL""" 10
+.el .IP "\f(CWMATHARRENV\fR,\f(CWMATHARRREPL\fR" 10
+.IX Item "MATHARRENV,MATHARRREPL"
+as \f(CW\*(C`MATHENV\*(C'\fR,\f(CW\*(C`MATHREPL\*(C'\fR but for equation arrays
+.Sp
+[ Default: \f(CW\*(C`MATHARRENV\*(C'\fR=\f(CW\*(C`eqnarray\e*?\*(C'\fR\ , \f(CW\*(C`MATHREPL\*(C'\fR=\f(CW\*(C`eqnarray\*(C'\fR\ ]
+.ie n .IP """ARRENV""" 10
+.el .IP "\f(CWARRENV\fR" 10
+.IX Item "ARRENV"
+If a match to \f(CW\*(C`ARRENV\*(C'\fR is found within an inline math environment within a deleted or added block, then the inlined math 
+is surrounded by \f(CW\*(C`\embox{\*(C'\fR...\f(CW\*(C`}\*(C'\fR.  This is necessary as underlining does not work within inlined array environments.
+.Sp
+[ Default: \f(CW\*(C`ARRENV\*(C'\fR=\f(CW\*(C`(?:array|[pbvBV]matrix)\*(C'\fR\ 
+.ie n .IP """COUNTERCMD""" 10
+.el .IP "\f(CWCOUNTERCMD\fR" 10
+.IX Item "COUNTERCMD"
+If a command in a deleted block which is also in the textcmd list matches \f(CW\*(C`COUNTERCMD\*(C'\fR then an
+additional command \f(CW\*(C`\eaddtocounter{\*(C'\fR\fIcntcmd\fR\f(CW\*(C`}{\-1}\*(C'\fR, where \fIcntcmd\fR is the matching command, is appended in the diff file such that the numbering in the diff file remains synchronized with the
+numbering in the new file.
+.Sp
+[ Default: \f(CW\*(C`COUNTERCMD\*(C'\fR=\f(CW\*(C`(?:footnote|part|section|subsection\*(C'\fR ...
+.Sp
+\&\f(CW\*(C`|subsubsection|paragraph|subparagraph)\*(C'\fR  ]
+.SH "BUGS"
+.IX Header "BUGS"
+\&\s-1UTF\-8\s0 support requires a relatively new version of perl (5.8.0 is sufficient 
+but 5.6.2 up would work \s-1OK\s0, too).
+.PP
+Option allow-spaces not implemented entirely consistently. It breaks
+the rules that number and type of white space does not matter, as
+different numbers of inter-argument spaces are treated as significant.
+.PP
+Please send bug reports
+to \fItilmann@esc.cam.ac.uk\fR.  Include the serial number of \fIlatexdiff\fR
+(from comments at the top of the source or use \fB\-\-version\fR).  If you come across latex
+files that are error-free and conform to the specifications set out
+above, and whose differencing still does not result in error-free
+latex, please send me those files, ideally edited to only contain the
+offending passage as long as that still reproduces the problem. 
+.SH "SEE ALSO"
+.IX Header "SEE ALSO"
+latexrevise
+.SH "PORTABILITY"
+.IX Header "PORTABILITY"
+\&\fIlatexdiff\fR does not make use of external commands and thus should run
+on any platform  supporting Perl 5.6 or higher.  If files with encodings 
+other than \s-1ASCII\s0 or \s-1UTF\-8\s0 are processed, Perl 5.8 or higher is required.
+.PP
+The standard version of \fIlatexdiff\fR requires installation of the Perl package
+\&\f(CW\*(C`Algorithm::Diff\*(C'\fR (available from \fIwww.cpan.org\fR \- 
+\&\fIhttp://search.cpan.org/~nedkonz/Algorithm\-Diff\-1.15\fR) but a stand-alone
+version, \fIlatexdiff-so\fR, which has this package inlined, is available, too.
+\&\fIlatexdiff-fast\fR requires the \fIdiff\fR command to be present.
+.SH "AUTHOR"
+.IX Header "AUTHOR"
+Copyright (C) 2004\-2007 Frederik Tilmann
+.PP
+This program is free software; you can redistribute it and/or modify
+it under the terms of the \s-1GNU\s0 General Public License Version 2
+.PP
+Contributors of fixes and additions: V. Kuhlmann, J. Paisley, N. Becker, T. Doerges, K. Huebner
+Thanks to everyone who send in bug reports.
diff --git a/Master/texmf/doc/man/man1/latexrevise.1 b/Master/texmf/doc/man/man1/latexrevise.1
new file mode 100644
index 00000000000..283c614677b
--- /dev/null
+++ b/Master/texmf/doc/man/man1/latexrevise.1
@@ -0,0 +1,235 @@
+.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14
+.\"
+.\" Standard preamble:
+.\" ========================================================================
+.de Sh \" Subsection heading
+.br
+.if t .Sp
+.ne 5
+.PP
+\fB\\$1\fR
+.PP
+..
+.de Sp \" Vertical space (when we can't use .PP)
+.if t .sp .5v
+.if n .sp
+..
+.de Vb \" Begin verbatim text
+.ft CW
+.nf
+.ne \\$1
+..
+.de Ve \" End verbatim text
+.ft R
+.fi
+..
+.\" Set up some character translations and predefined strings.  \*(-- will
+.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
+.\" double quote, and \*(R" will give a right double quote.  | will give a
+.\" real vertical bar.  \*(C+ will give a nicer C++.  Capital omega is used to
+.\" do unbreakable dashes and therefore won't be available.  \*(C` and \*(C'
+.\" expand to `' in nroff, nothing in troff, for use with C<>.
+.tr \(*W-|\(bv\*(Tr
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.ie n \{\
+.    ds -- \(*W-
+.    ds PI pi
+.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
+.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
+.    ds L" ""
+.    ds R" ""
+.    ds C` ""
+.    ds C' ""
+'br\}
+.el\{\
+.    ds -- \|\(em\|
+.    ds PI \(*p
+.    ds L" ``
+.    ds R" ''
+'br\}
+.\"
+.\" If the F register is turned on, we'll generate index entries on stderr for
+.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
+.\" entries marked with X<> in POD.  Of course, you'll have to process the
+.\" output yourself in some meaningful fashion.
+.if \nF \{\
+.    de IX
+.    tm Index:\\$1\t\\n%\t"\\$2"
+..
+.    nr % 0
+.    rr F
+.\}
+.\"
+.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
+.\" way too many mistakes in technical documents.
+.hy 0
+.if n .na
+.\"
+.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
+.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
+.    \" fudge factors for nroff and troff
+.if n \{\
+.    ds #H 0
+.    ds #V .8m
+.    ds #F .3m
+.    ds #[ \f1
+.    ds #] \fP
+.\}
+.if t \{\
+.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
+.    ds #V .6m
+.    ds #F 0
+.    ds #[ \&
+.    ds #] \&
+.\}
+.    \" simple accents for nroff and troff
+.if n \{\
+.    ds ' \&
+.    ds ` \&
+.    ds ^ \&
+.    ds , \&
+.    ds ~ ~
+.    ds /
+.\}
+.if t \{\
+.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
+.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
+.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
+.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
+.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
+.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
+.\}
+.    \" troff and (daisy-wheel) nroff accents
+.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
+.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
+.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
+.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
+.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
+.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
+.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
+.ds ae a\h'-(\w'a'u*4/10)'e
+.ds Ae A\h'-(\w'A'u*4/10)'E
+.    \" corrections for vroff
+.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
+.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
+.    \" for low resolution devices (crt and lpr)
+.if \n(.H>23 .if \n(.V>19 \
+\{\
+.    ds : e
+.    ds 8 ss
+.    ds o a
+.    ds d- d\h'-1'\(ga
+.    ds D- D\h'-1'\(hy
+.    ds th \o'bp'
+.    ds Th \o'LP'
+.    ds ae ae
+.    ds Ae AE
+.\}
+.rm #[ #] #H #V #F C
+.\" ========================================================================
+.\"
+.IX Title "LATEXREVISE 1"
+.TH LATEXREVISE 1 "2007-09-07" "perl v5.8.5" " "
+.SH "NAME"
+latexrevise \- selectively remove markup and text from latexdiff output
+.SH "SYNOPSIS"
+.IX Header "SYNOPSIS"
+\&\fBlatexrevise\fR [ \fB\s-1OPTIONS\s0\fR ] [ \fIdiff.tex\fR ] > \fIrevised.tex\fR
+.SH "DESCRIPTION"
+.IX Header "DESCRIPTION"
+\&\fIlatexrevise\fR reads a file \f(CW\*(C`diff.tex\*(C'\fR (output of \fIlatexdiff\fR), and remove the markup commands. 
+If no filename is given the input is read from standard input. The command can be used
+in \fI\s-1ACCEPT\s0\fR, \fI\s-1DECLINE\s0\fR, or \fI\s-1SIMPLIFY\s0\fR mode, or can be used to remove user-defined
+latex commands from the input (see \fB\-c\fR, \fB\-e\fR, \fB\-m\fR, and \fB\-n\fR below). 
+In \fI\s-1ACCEPT\s0\fR mode, all appended text fragments  (or preamble lines)
+are kept, and all discarded text fragments (or preamble lines) are
+deleted.  
+In \fI\s-1DECLINE\s0\fR mode, all discarded text fragments are kept, and all appended 
+text fragments are deleted.  
+If you wish to keep some changes, edit the diff.tex file in
+advance, and manually remove those tokens  which would otherwise be
+deleted.  Note that \fIlatexrevise\fR only pays attention to the \f(CW\*(C`\eDIFaddbegin\*(C'\fR,
+\&\f(CW\*(C`\eDIFaddend\*(C'\fR, \f(CW\*(C`\eDIFdelbegin\*(C'\fR, and \f(CW\*(C`\eDIFdelend\*(C'\fR tokens and corresponding \s-1FL\s0
+varieties.  All \f(CW\*(C`\eDIFadd\*(C'\fR and \f(CW\*(C`\eDIFdel\*(C'\fR commands (but not their contents) are 
+simply deleted.   The commands added by latexdiff to the preamble are also
+removed.
+In \fI\s-1SIMPLIFY\s0\fR mode, \f(CW\*(C`\eDIFaddbegin, \eDIFaddend, \eDIFdelbegin, \eDIFdelend\*(C'\fR
+tokens and their corresponding \f(CW\*(C`FL\*(C'\fR varieties are kept but all other markup (e.g. \f(CW\*(C`DIFadd\*(C'\fR and <\eDIFdel>) is removed.  The result
+will not in general be valid latex-code but it will be easier to read and edit in 
+preparation for a subsequent run in \fI\s-1ACCEPT\s0\fR or \fI\s-1DECLINE\s0\fR mode.  
+In \fI\s-1SIMPLIFY\s0\fR mode the preamble is left unmodified.
+.SH "OPTIONS"
+.IX Header "OPTIONS"
+.IP "\fB\-a\fR or \fB\-\-accept\fR" 4
+.IX Item "-a or --accept"
+Run in \fI\s-1ACCEPT\s0\fR mode (delete all blocks marked by \f(CW\*(C`\eDIFdelbegin\*(C'\fR and \f(CW\*(C`\eDIFdelend\*(C'\fR).
+.IP "\fB\-d\fR or \fB\-\-decline\fR" 4
+.IX Item "-d or --decline"
+Run in \fI\s-1DECLINE\s0\fR mode (delete all blocks marked by \f(CW\*(C`\eDIFaddbegin\*(C'\fR
+and \f(CW\*(C`\eDIFaddend\*(C'\fR).
+.IP "\fB\-s\fR or \fB\-\-simplify\fR" 4
+.IX Item "-s or --simplify"
+Run in \fI\s-1SIMPLIFY\s0\fR mode (Keep all \f(CW\*(C`\eDIFaddbegin\*(C'\fR, \f(CW\*(C`\eDIFaddend\*(C'\fR, 
+\&\f(CW\*(C`\eDIFdelbegin\*(C'\fR, \f(CW\*(C`\eDIFdelend\*(C'\fR tokens, but remove all other latexdiff
+markup from body).  
+.PP
+Note that the three mode options are mutually exclusive.  If no mode option is given,
+\&\fIlatexrevise\fR simply removes user annotations and markup according to the following four
+options.
+.IP "\fB\-c cmd\fR or \fB\-\-comment=cmd\fR" 4
+.IX Item "-c cmd or --comment=cmd"
+Remove \f(CW\*(C`\ecmd{...}\*(C'\fR sequences.  \f(CW\*(C`cmd\*(C'\fR is supposed to mark some explicit 
+anotations which should be removed from the file before 
+release.
+.IP "\fB\-e envir\fR or \fB\-\-comment\-environment=envir\fR" 4
+.IX Item "-e envir or --comment-environment=envir"
+Remove explicit annotation environments from the text, i.e. remove
+.Sp
+.Vb 3
+\&            \ebegin{envir}
+\&            ...
+\&            \eend{envir}
+.Ve
+.Sp
+blocks.
+.IP "\fB\-m cmd\fR or \fB\-\-markup=cmd\fR" 4
+.IX Item "-m cmd or --markup=cmd"
+Remove the markup command \f(CW\*(C`\ecmd\*(C'\fR but leave its argument, i.e.
+turn \f(CW\*(C`\ecmd{abc}\*(C'\fR into \f(CW\*(C`abc\*(C'\fR.  
+.IP "\fB\-n envir\fR or \fB\-\-markup\-environment=envir\fR" 4
+.IX Item "-n envir or --markup-environment=envir"
+Similarly, remove \f(CW\*(C`\ebegin{envir}\*(C'\fR and \f(CW\*(C`\eend{envir}\*(C'\fR commands but 
+leave content of the environment in the text.
+.IP "\fB\-V\fR or \fB\-\-verbose\fR" 4
+.IX Item "-V or --verbose"
+Verbose output
+.IP "\fB\-q\fR or \fB\-\-no\-warnings\fR" 4
+.IX Item "-q or --no-warnings"
+Do not warn users about \f(CW\*(C`\eDIDadd{..}\*(C'\fR or \f(CW\*(C`\eDIFdel{..}\*(C'\fR statements
+which should have been removed already.
+.SH "BUGS"
+.IX Header "BUGS"
+The current version is a beta version which has not yet been
+extensively tested, but worked fine locally.  Please send bug reports
+to \fItilmann@esc.cam.ac.uk\fR.  Include the serial number of \fIlatexrevise\fR
+(from comments at the top of the source).  If you come across latexdiff
+output which is not processed correctly by \fIlatexrevise\fR please include the
+problem file as well as the old and new files on which it is based,
+ideally edited to only contain the offending passage as long as that still
+reproduces the problem.
+.PP
+\&\fIlatexrevise\fR gets confused by commented \f(CW\*(C`\ebegin{document}\*(C'\fR or 
+\&\f(CW\*(C`\eend{document}\*(C'\fR statements
+.SH "SEE ALSO"
+.IX Header "SEE ALSO"
+latexdiff
+.SH "PORTABILITY"
+.IX Header "PORTABILITY"
+\&\fIlatexrevise\fR does not make use of external commands and thus should run
+on any platform  supporting \s-1PERL\s0 v5 or higher. 
+.SH "AUTHOR"
+.IX Header "AUTHOR"
+Copyright (C) 2004 Frederik Tilmann
+.PP
+This program is free software; you can redistribute it and/or modify
+it under the terms of the \s-1GNU\s0 General Public License Version 2
diff --git a/Master/tlpkg/bin/tlpkg-ctan-check b/Master/tlpkg/bin/tlpkg-ctan-check
index 339d37e7185..ad9dbe7bd2b 100755
--- a/Master/tlpkg/bin/tlpkg-ctan-check
+++ b/Master/tlpkg/bin/tlpkg-ctan-check
@@ -146,8 +146,9 @@ my @WorkingTLP = qw(
         l2picfaq l2tabu l2tabu-english l2tabu-french l2tabu-it l2tabu-spanish
           labbook labelcas labels lastpage
           latex latex-doc-ptr latex-notes-zh-cn latex-veryshortguide
+          latex-course latex-tds
           latex2e-help-texinfo latex2man
-          latex-course latex-tds latexcheat latexcheat-ptbr latexmk latexmp
+          latexcheat latexcheat-ptbr latexdiff latexmk latexmp
           layouts lcd lcg lcyw leading leaflet ledmac leftidx lettrine
           lewis lfb lgreek lh
           libertine libris limap linearA lineno linguex
diff --git a/Master/tlpkg/libexec/ctan2tds b/Master/tlpkg/libexec/ctan2tds
index 3dc049ad582..e64ce58adcb 100755
--- a/Master/tlpkg/libexec/ctan2tds
+++ b/Master/tlpkg/libexec/ctan2tds
@@ -657,6 +657,7 @@ $Master = "$mydir/../..";
  'knuth'		=> '&POSTknuth',
  'koma-script'          => '&POSTkomascript',
  'latex2man'		=> '&POSTlatex2man',
+ 'latexdiff'		=> '&POSTlatexdiff',
  'lithuanian'		=> '&POSTlithuanian',
  'montex'		=> '&POSTmontex',
  'pgf'			=> '&POSTpgf',
@@ -700,6 +701,7 @@ $standardsource='\.fdd|\.dtx|\.ins|\.c$|Makefile|configure.*|install-sh|\.drv';
  'latex-doc-ptr',	'NULL',	# doc package
  'latex2e-help-texinfo','NULL',	# doc package
  'latex2man',		'NULL',	# leave Makefile
+ 'latexdiff',		'NULL',	# leave Makefile
  'mpman-ru',		'NULL',	# doc package
  'ot2cyr',		'\.afm|\.etx|' . $standardsource,
  'pdfx',		'rvdtx\.sty|' . $standardsource,
@@ -1489,6 +1491,7 @@ $standardxmt='\.xmt';
  'findhyph'		=> 'findhyph$',
  'fragmaster'		=> 'fragmaster.pl',
  'latex2man'		=> 'latex2man$',
+ 'latexdiff'		=> 'latex(diff-so|diff-vc|revise)$',
  'latexmk'		=> '\.pl$',
  'listings-ext'		=> '\.sh$',
  'mkgrkindex'		=> 'mkgrkindex$',
@@ -1518,6 +1521,7 @@ $standardxmt='\.xmt';
 %specialmans = (
  'epstopdf'		=> 'epstopdf.1',
  'findhyph'		=> 'findhyph.1',
+ 'latexdiff'		=> '\.1$',
  'latexmk'		=> 'latexmk.1',
  'perltex'		=> 'perltex.1',
  'pkfix-helper'		=> 'pkfix-helper.1',
@@ -3762,14 +3766,12 @@ sub POSTlatex2man
   print "YOU-MUST-DO! update /tmp/$package.info into texmf/doc/info\n";
 }
 
-sub POSTlibertine
+sub POSTlatexdiff
 {
-  print "POST$package - remove nosource docs";
-  # post routine instead of moreclean because we use MAKEcopy.
-  # doable one way or another, but skipping for now. xx
-  # 
-  # no source for doku.pdf.
-  &SYSTEM ("$RM doc/fonts/libertine/*libertine[dD]oku.pdf");
+  print "POST$package - rename $package-so to $package.pl\n";
+  # to avoid special case in w32 wrapper
+  my $dir = "$DEST/scripts/$package";
+  &SYSTEM ("$MV $dir/latexdiff-so $dir/latexdiff.pl");  
 }
 
 sub POSTlithuanian
diff --git a/Master/tlpkg/tlpsrc/00texlive.autopatterns.tlpsrc b/Master/tlpkg/tlpsrc/00texlive.autopatterns.tlpsrc
index 7dbc0d9518c..cc1fd970a13 100644
--- a/Master/tlpkg/tlpsrc/00texlive.autopatterns.tlpsrc
+++ b/Master/tlpkg/tlpsrc/00texlive.autopatterns.tlpsrc
@@ -22,6 +22,7 @@ runpattern Package t texmf-dist tex %NAME%
 runpattern Package t texmf-dist vtex %NAME%
 srcpattern Package t texmf-dist source %NAME%
 docpattern Package t texmf-dist doc %NAME%
+docpattern Package f texmf/doc/man/man1/%NAME%.*
 
 # auto patterns for category TLCore
 docpattern TLCore t texmf doc %NAME%
diff --git a/Master/tlpkg/tlpsrc/collection-binextra.tlpsrc b/Master/tlpkg/tlpsrc/collection-binextra.tlpsrc
index 6b40a1fcf7d..2803589c234 100644
--- a/Master/tlpkg/tlpsrc/collection-binextra.tlpsrc
+++ b/Master/tlpkg/tlpsrc/collection-binextra.tlpsrc
@@ -24,6 +24,7 @@ depend fragmaster
 depend hyphenex
 depend lacheck
 depend latex2man
+depend latexdiff
 depend latexmk
 depend listings-ext
 depend mkind-english
diff --git a/Master/tlpkg/tlpsrc/latexdiff.tlpsrc b/Master/tlpkg/tlpsrc/latexdiff.tlpsrc
new file mode 100644
index 00000000000..7ab6ed498b3
--- /dev/null
+++ b/Master/tlpkg/tlpsrc/latexdiff.tlpsrc
@@ -0,0 +1,2 @@
+docpattern +f texmf/doc/man/man1/latexdiff-vc.*
+docpattern +f texmf/doc/man/man1/latexrevise.*