#!@runtime_perl@
# Original version by Ilya Zakharevich. Minor updates by the PARI group
# Features:
#      % at the end of a line followed by \n\n is recognized as end of 
#      paragraph :-(
#
# Original change log is at bottom.
#
# Options:
#	linelength=75		# Cut at this line
#	maxdef=400		# definition loops: croak if many substitutions
#	debug=0
#	by_par=0		# Expect each paragraph to be terminated
#				# by *exactly* 2 "\n", and do not print
#				# an extra "\n" between paragraphs
#	TeX			# Assume it is not LaTeX
#	ragged			# leave right ragged
#	noindent		# assume \noindent everywhere
#	ignorefonts		# make math fonts (\mathfrak etc) into NOPs
#	scissors		# Symbol to emit when a long line is cut
$@ = '';
$opt_TeX      = 1;
$opt_noindent = 1;
$opt_ragged   = 1;
$opt_by_par   = 1;
eval '
  use Getopt::Long;
  &GetOptions(
    "linelength=i" => \$opt_linelength,
    "maxdef=i" => \$opt_maxdef,
    "debug=i" => \$opt_debug,
    "by_par" => \$opt_by_par,
    "TeX" => \$opt_TeX,
    "ragged" => \$opt_ragged,
    "noindent" => \$opt_noindent,
    "ignorefonts" => \$opt_ignorefonts,
    "scissors=s" => \$opt_scissors,
    "noflush" => \$opt_noflush)
';
if ($@ && $@ !~ /Getopt\/Long/) {
  warn "Errors while parsing command line options $@\n";
}
$linelength= $opt_linelength || 75;
$maxdef= $opt_maxdef || 10000;
$debug=$opt_debug;
$opt_scissors = "---8<---8<---" unless defined $opt_scissors;

$notusualtoks="\\\\" . '\${}^_~&@';
$notusualtokenclass="[$notusualtoks]";
$usualtokenclass="[^$notusualtoks]";
$macro='\\\\([^a-zA-Z]|([a-zA-Z]+\s*))'; # Why \\\\? double interpretation!
$active="$macro|\\\$\\\$|$notusualtokenclass";
$tokenpattern="$usualtokenclass|$active";
$multitokenpattern="$usualtokenclass+|$active";

$| = 1 unless $opt_noflush;

# Format of the record: height,length,baseline,expandable-spaces,string
# The string is not terminated by \n, but separated into rows by \n.
# height=0 denotes expandable string
# Baseline=3 means the 4th row is the baseline

sub debug_print_record {
  local($h,$l,$b,$xs,$s) = split /,/, shift, 5;
  local(@arr) = split /\n/, $s;
  print STDERR "len=$l, h=$h, b=$b, exp_sp=$xs.\n";
  local($i) = 0;
  for (@arr) {
    local($lead) = ($i++ == $b) ? 'b [' : '  [';
    print STDERR "$lead$_]\n";
  }
  while ($i < $h) {		# Empty lines may skipped
    local($lead) = ($i++ == $b) ? 'b' : '';
    print STDERR "$lead\n";
  }
}

# Takes length and a record, returns 2 records

sub cut {
  local($length)=(shift);
  local($h,$l,$b,$sp,$str)=split(/,/,shift,5);
  local($st1,$st2)=("","");
  local($sp1,$sp2,$first,$l2)=(0,0,1,$l-$length);
  return (shift,&empty) if $l2<0;
  if ($h) {
    for (split(/\n/,$str,$h)) {
      if (!$first) {
        $st1 .= "\n";
        $st2 .= "\n";
      } else {$first=0;}
      $st1 .= substr($_,0,$length);
      $st2 .= substr($_,$length);
    }
  } else {
    $st1 = substr($str,0,$length);
    $st2 = substr($str,$length);
    #if ($sp && ($st1 =~ /(\S)(\s+\S*)$/)) {
    # $st2 = $2 . $st2;
    # $st1 = $` . $1;
    # $sp1 = ($st1 =~ /(\s)/g);
    # $sp2 = ($st2 =~ /(\s)/g);
    #}  
  }
  return ("$h,$length,$b,$sp1,$st1","$h,$l2,$b,$sp2,$st2");
}

# Outputs a record

sub printrecord {
  warn "Printing $_[0]\n__ENDPRINT__\n" if $debug & $debug_record;  
  local($h,$l,$b,$sp,$str)=split(/,/,shift,5);
  print $str,"\n";
} 

# Joins two records

sub join {
  local($h1,$l1,$b1,$sp1,$str1)=split(/,/,shift,5);
  local($h2,$l2,$b2,$sp2,$str2)=split(/,/,shift,5);
  $h1 || $h1++;
  $h2 || $h2++;
  local($h,$l,$b,$sp,$str,@str,@str2)=(0,0,0,$sp1+$sp2,"");
  $b = $b1 > $b2 ? $b1 : $b2;
  # Calculate space below baseline
  $h = $h1-$b1 > $h2-$b2 ? $h1-$b1 : $h2-$b2;
  # And height
  $h += $b;
  $l=$l1+$l2;
  @str="" x $h;
  @str[$b-$b1 .. $b-$b1+$h1-1]=split(/\n/,$str1,$h1);
  @str2[0..$h2-1]=split(/\n/,$str2,$h2);
  unless (length($str2[$b2])) {
    $str2[$b2] = ' ' x $l2;	# Needed for length=0 "color" strings
                                # in the baseline.
  }
  if ($debug & $debug_record && (grep(/\n/,@str) || grep(/\n/,@str2))) {
    warn "\\n found in \@str or \@str2";
    warn "`$str1', need $h1 rows\n";
    warn "`$str2', need $h2 rows\n";
  }
  # This is may be wrong if a zero-length record with escape sequences
  # is appended to with something not on the same row...  But
  # apparently, it should be OK for PARI...
  for (0..$h2-1) {
    $str[$b-$b2+$_] .= " " x ($l1 - length ($str[$b-$b2+$_])) . $str2[$_];
  } 
  return "$h,$l,$b,$sp," . join("\n",@str);
} 

# The current line is contained in the array @out of records and, possibly,
# one additional record $last. If $last exists, $islast is set to 1.
# The output channel length is contained in $linelength, the accumulated
# length of @out and $last is contained in $curlength.
# We guaranty that if $curlength>$linelength, then @out is empty.

# Gets a length of a record

sub length {
  (warn "Wrong format of a record `$_[0]'", return 0)
      unless $_[0] =~ /^\d+,(\d+)/;
  $1;
}

# Gets a height of a record

sub height {
  (warn "Wrong format of a record `$_[0]'", return 0)
      unless $_[0] =~ /^(\d+),/;
  $1;
}

# Sets baseline of a record, Usage s...(rec,base)

sub setbaseline {
  (warn("Wrong format of a record `$_[0]'"), return undef)
      unless $_[0] =~ s/^(\d+,\d+,)(\d+)/\1$_[1]/;
}

# The hierarchical structure: the records to work are in the array @out.
# The array @chunks keeps the beginning record of the chunks,
# The array @level keeps the beginning chunks of the given level.
# The last chunk can begin after the last record if this chunk is still empty.

# We do not keep the inner structure of the chunk unless it is the last
# chunk on the given level.

# Each record is a rectangle to output to the "page".

# Each chunk is a sequence of records which reflect one finished subgroup
# on the given level.

# Each level is a sequence of chunks which correspond to a
# not-yet-finished group in TeX input.


# The parallel to @level array @wait
# contains an event we wait to complete the given level of array.

# Chunks on a given level

# Used to expand spaces

sub exp_sp {$c1++;$c2=0 if $c1>$re; return " " x ($c2+$fr+1);}

# Outputs the outermost level of the output list (until the start of level 1)
# If gets a true argument, does not expand spaces

sub print {
  warn "Printing...\n" if $debug & $debug_flow; 
  local($last,$l,$exp) = ($#level? $chunks[$level[1]]-1: $#out);
  ($last >=0) || return;
  $l=&length($out[0]);
  if ($last >= 1) {
    for (1..$last) {
      $l += &length($out[$_]);
    }
  }
  if ($debug & $debug_length)  {
    if ($l != $curlength) {
      for (0..$last) {
        warn "Wrong lengths Record $_ $out[$_]\n__ENDREC__\n" ; 
      }
    } 
  } 
  $curlength=$l;
  warn "l=$l, linelength=$linelength, curlength=$curlength\n"
    if $debug & $debug_length;
 IF_L:
 {
  if (!shift && ($l=$linelength-$curlength)>=0) {
    warn "entered branch for long string\n"
      if $debug & $debug_length;
    $exp=0;
    (($out[$last] =~ s/\s+$//) && ($l+=length($&))) 
        if $out[$last] =~ /^0,/;
    warn "l=$l with whitespace\n"
      if $debug & $debug_length;
    last IF_L if $l<=0;
    local($str,$h,$fr,$re,$c1,$c2,@t);
    for (0..$last) {
      ($str,$h)=(split(/,/,$out[$_],5))[4,0];
      (@t = ($str =~ /( )/g), $exp+=@t) if (!$h);
    } 
    if ($exp) {
      $re=$l % $exp;
      $fr=int(($l-$re)/$exp);
      warn "$l Extra spaces in $exp places, Fr=$fr," . 
          " Remainder=$re, LL=$linelength, CL=$curlength\n" if $debug & $debug_length;
      $c1=0;
      $c2=1;
      for (0..$last) {
        ($str,$h)=(split(/,/,$out[$_],5))[4,0];
        unless ($h || $opt_ragged) {
          $str =~ s/ /&exp_sp/ge;
          $out[$_]=&string2record($str);
        }
      } 
    }     
  } 
  else {warn "Do not want to expand $l spaces\n" if $debug & $debug_length;}
 }
  if ($last >= 1) {
    for (1..$last) {
      $out[0] = &join($out[0],$out[$_]);
    }
  }
  $l=&length($out[0]);
  warn "LL=$linelength, CurL=$curlength, OutL=$l\n" if $debug & $debug_length;  
  &printrecord($out[0]);
  $curlength=0;
  if ($#out>$last) {
    @out=@out[$last+1..$#out];
    for (0..$#chunks) {$chunks[$_] -= $last+1;}
  } else {
    @out=();
  } 
  if ($#level) {
    splice(@chunks,1,$level[1]-2);
  } else {
    @chunks=(0);
  }   
}
  
# Cuts prepared piece and arg into printable parts (unfinished)
# Suppose that level==0

sub prepare_cut {
  warn "Preparing to cut $_[0]\n" if $debug & $debug_flow;  
  warn "B:Last chunk number $#chunks, last record $#out\n" if $debug & $debug_flow;
  (warn "\$#level non 0", return $_[0]) if ($#level!=0);
  local($lenadd)=(&length($_[0]));
  local($lenrem)=($linelength-$curlength);
  if ($lenadd+$curlength<=$linelength) {
    warn "No need to cut, extra=$lenrem\n" if $debug & $debug_flow; 
    return $_[0];
  }
  # Try to find a cut in the added record before $lenrem
  local($rec)=@_;
  local($h,$str,$ind,@p)=(split(/,/,$rec,5))[0,4];
  local($good)=(0);
  if ($h<2) {
    while ($lenrem<$lenadd && ($ind=rindex($str," ",$lenrem))>-1) {
      warn "Cut found at $ind, lenrem=$lenrem\n" if $debug & $debug_flow; 
      $good=1;
      # $ind=1 means we can cut 2 chars 
      @p= &cut($ind+1,$rec);
      warn "After cut: @p\n" if $debug & $debug_record; 
      push(@out,$p[0]);
      $curlength+=$ind+1;
      #if ($#out!=$chunks[$#chunks]) {push(@chunks,$#out);}
      &print();
      $rec=$p[1];
      ($lenadd,$str)=(split(/,/,$rec,5))[1,4];
      $lenrem=$linelength;
    }
    return $rec if $good;
  }
  # If the added record is too long, there is no sense in cutting
  # things we have already, since we will cut the added record anyway...
  local($forcedcut);
  if ($lenadd > $linelength && $lenrem) {
      @p= &cut($lenrem,$rec);
      warn "After forced cut: @p\n" if $debug & $debug_record;
      push(@out,$p[0]);
      $curlength+=$lenrem;
      &print();
      $rec=$p[1];
      ($lenadd,$str)=(split(/,/,$rec,5))[1,4];
      $lenrem=$linelength;
  }
  # Now try to find a cut before the added record
  if ($#out>=0 && !$forcedcut) {
    for (0..$#out) {
      ($h,$str)=(split(/,/,$out[$#out-$_],5))[0,4];
      if ($h<2 && ($ind=rindex($str," "))>-1 && ($ind>0 || $_<$#out)) {
        warn "Cut found at $ind, in chunk $#out-$_\n" 
            if $debug & $debug_flow;  
        # split at given position
        @p=&cut($ind+1,$out[$#out-$_]);
        $out[$#out-$_]=$p[0];
        @p=($p[1],@out[$#out-$_+1..$#out]);
        @out=@out[0..$#out-$_];
warn "\@p is !", join('!', @p), "!\n\@out is !", join('!', @out), "!\n" 
            if $debug & $debug_flow;	
        &print();
	warn "did reach that\n"
	  if $debug & $debug_length;
        @out=@p;
        $good=1;
        $curlength=0;
        for (@out) {$curlength+=&length($_);}
        last;
      }
      warn "did reach wow-this\n"
	if $debug & $debug_length;
    }
    warn "did reach this\n"
      if $debug & $debug_length;
  }
  return &prepare_cut if $good;
  warn "No cut found!\n" if $debug & $debug_flow; 
  # If anything else fails use force
  &print();
  print "$opt_scissors\n" if length($opt_scissors) && $h > 1;
  while (&length($rec)>$linelength) {
    @p=&cut($linelength,$rec);
    @out=($p[0]);
    &print();
    print "$opt_scissors\n" if length($opt_scissors) && $h > 1;
    $rec=$p[1];
  } 
  $curlength=0;
  return $rec;
} 

# Adds a record to the output list

sub commit {
  warn "Adding $_[0]\n" if $debug & $debug_flow;  
  warn "B:Last chunk number $#chunks, last record $#out\n" if $debug & $debug_flow;
  local($rec)=@_;
  if ($#level==0) {
    local($len)=&length($_[0]);
    if ($curlength+$len>$linelength) {
      $rec=&prepare_cut;
      $len=&length($rec);
    } 
    $curlength+=$len;
  }
  push(@out,$rec);
  if ($#out!=$chunks[$#chunks]) {push(@chunks,$#out);}
  warn "a:Last chunk number $#chunks, last record $#out, the first chunk\n" if $debug & $debug_flow;
  warn " on the last level=$#level is $level[$#level], waiting for $wait[$#level]\n" if $debug & $debug_flow;
  if ($#level && $wait[$#level] == $#chunks-$level[$#level]+1) {
    local($sub,$arg)=($action[$#level]);
    if ($sub eq "") {&finish($wait[$#level]);}
    else {
      &callsub($sub);
    }
  }
  warn "curlength=$curlength on level=$#level\n" if $debug & $debug_length;
} 

# Calls a subroutine, possibly with arguments

sub callsub {
  local($sub)=(shift);
  index($sub,";")>=0?
    (($sub,$arg)=split(";",$sub,2), &$sub($arg)):
      &$sub;
}

# Simulates Removing a record from the output list (unfinished)

sub uncommit {
  warn "Deleting...\n" if $debug & $debug_flow; 
  warn "B:Last chunk number $#chunks, last record $#out\n" if $debug & $debug_flow;
  (warn "Nothing to uncommit", return) if $#out<0;
  if ($#level==0) {
    local($len)=&length($out[$#out]);
    $curlength-=$len;
  }
  local($rec);
  $rec=$out[$#out];
  $out[$#out]=&empty();
  warn "UnCommit: now $chunks[$#chunks] $rec\n__ENDREC__\n"
      if $debug & $debug_record;  
  #if ($#out<$chunks[$#chunks]) {pop(@chunks);}
  warn "a:Last chunk number $#chunks, last record $#out, the first chunk\n" if $debug & $debug_flow;
  warn " on the last level=$#level is $level[$#level], waiting for $wait[$#level]" if $debug & $debug_flow;
  warn "curlength=$curlength on level=$#level\n" if $debug & $debug_length;
  return $rec;
} 

# finish($event, $force_one_group)

# Finish the inner scope with the event $event. If this scope is empty,
# add an empty record.  If finishing the group would bring us to toplevel
# and $force_one_group is not set, can break things into chunks to improve
# line-breaking.

# No additional action is executed

sub finish {
  warn "Finishing with $_[0]\n" if $debug & $debug_flow;  
  local($event,$len,$rec)=(shift);
  if (($wait[$#level] ne "") && ($wait[$#level] ne $event)) {
    warn "Got `$event' while waiting for `$wait[$#wait]', rest=$par";
  }
  warn "Got finishing event `$event' in the outermost block, rest=$par" 
      unless $#level;
  return unless $#level;
  if ($#out<$chunks[$level[$#level]]) {push(@out,&empty);}
  # Make anything after $level[$#level] one chunk if there is anything
  warn "B:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  $#chunks=$level[$#level]; #if $chunks[$level[$#level]]<=$#out;
  local(@t);
  if ($#level==1 && !$_[0]) {
    @t=@out[$chunks[$#chunks]..$#out];
    $#out=$chunks[$#chunks]-1;
  }
  #  $#chunks-- if $chunks[$#chunks-1]==$chunks[$#chunks];
  $#level--;
  $#action--;
  $#tokenByToken--;
  $#wait--;
  if ($#level==0 && !$_[0]) {
    for (@t) {&commit($_);}
  }
  warn 
      "a:Last $#chunks, the first on the last level=$#level is $level[$#level]"
           if $debug & $debug_flow;
  if ($wait[$#level] == $#chunks-$level[$#level]+1) {
    local($sub)=($action[$#level]);
    if ($sub eq "") {&finish($wait[$#level]);}
    else {&callsub($sub);}
  }
} 

# finish level and discard it

sub finish_ignore {
        warn "Finish_ignoring with $_[0]\n" if $debug & $debug_flow;
        local($event,$len)=(shift);
        if (($wait[$#level] ne "") && ($wait[$#level] ne $event)) {
                warn "Got `$event' while waiting for `$wait[$#wait]', rest=$par";
        }
        warn "Got finishing event `$event' in the outermost block, rest=$par" unless $#level;
  $#out=$chunks[$level[$#level]]-1;
  pop(@level);
  pop(@tokenByToken);
  pop(@action);
  pop(@wait);
}

# Begin a new level with waiting for $event

# Special events: If number, wait this number of chunks

sub start {
  warn "Beginning with $_[0], $_[1]\n" if $debug & $debug_flow;
  warn "B:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  warn "#out=$#out, chunks[first of last level]=$chunks[$level[$#level]], chunk
s[-1]=$chunks[$#chunks]" if $debug & $debug_flow;

  # !@chunks: may be true in \noindent{1\over2}
  if (!@chunks || ($chunks[$level[$#level]]<=$#out && $chunks[$#chunks]<=$#out)) {
    # the last level is non empty
    push(@chunks,$#out+1);
  }
  push(@level,$#chunks);
  push(@tokenByToken,0);
  $wait[$#level]=shift;
  if ($#_<0) {$action[$#level]="";} else {$action[$#level]=shift;}
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
} 
    
# Asserts that the given number of chunks exists in the last level

sub assertHave {
  local($i,$ii)=(shift);
  if (($ii=$#chunks-$level[$#level]+1)<$i) {
    warn "Too few chunks ($ii) in inner level, expecting $i";
    return 0;
  }
  return 1;
} 

# Takes the last ARGUMENT chunks, collapse them to records

sub collapse {
  warn "Collapsing $_[0]...\n" if $debug & $debug_flow; 
  local($i,$ii,$_)=(shift);
  if (($ii=$#chunks-$level[$#level]+1)<$i) {
    warn "Too few chunks ($ii) in inner level, expecting $i";
    $i=$ii;
  }
  if ($i>0) {
    for (0..$i-1) {
      &collapseOne($#chunks-$_);
    } 
    for (1..$i-1) {
      $chunks[$#chunks-$_+1]=$chunks[$#chunks-$i+1]+$i-$_;
    } 
  } 
} 

# Collapses all the chunks on given level

sub collapseAll {&collapse($#chunks-$level[$#level]+1);}

# Collapses a given chunk in the array @out. No correction of @chunks is
# performed

sub collapseOne {
  local($n)=(shift);
  local($out,$last,$_)=($out[$chunks[$n]]);
  if ($n==$#chunks) {$last=$#out;} else {$last=$chunks[$n+1]-1;}
  warn "Collapsing_one $n (last=$#chunks), records $chunks[$n]..$last\n"
                if $debug & $debug_flow;
  return unless $last>$chunks[$n];
  warn "Collapsing chunk $n beginning at $chunks[$n], ending at $last\n" if $debug & $debug_flow; 
  for ($chunks[$n]+1..$last) {
    $out=&join($out,$out[$_]);
  } 
  splice(@out,$chunks[$n],$last+1-$chunks[$n],$out);
  # $#out-=$last-$chunks[$n]; #bug in perl?
  warn "Collapsed $chunks[$n]: $out[$chunks[$n]]\n__END__\n" if $debug & $debug_record;
} 

# Return an empty record

sub empty {
  return "0,0,0,0,";
} 

# Commits a record with a sum symbol

sub sum {
  &commit("4,3,2,0," . <<'EOF');
___
\   
 >
/__ 
EOF
} 

# Additional argument specifies if to make not-expandable, not-trimmable

sub string2record {
  local($h,$sp)=(0);
  if ($_[1]) {$h=1;$sp=0;}
  else {
    $sp=($_[0] =~ /(\s)/g);
    $sp || ($sp=0); # Sometimes it is undef?
  }
  return "$h," . length($_[0]) . ",0,$sp,$_[0]";
}

# The second argument forces the block length no matter what is the
# length the string (for strings with screen escapes).

sub record_forcelength {
  $_[0] =~ s/^(\d+),(\d+)/$1,$_[1]/;
}

sub finishBuffer {
  while ($#level>0) {&finish("");}
  &print(1);
} 

# Takes two records, returns a record that concatenates them vertically
# To make fraction simpler, baseline is the last line of the first record

sub vStack {
  local($h1,$l1,$b1,$sp1,$str1)=split(/,/,shift,5);
  local($h2,$l2,$b2,$sp2,$str2)=split(/,/,shift,5);
  $h1 || $h1++;
  $h2 || $h2++;
  local($h,$l,$b)=($h1+$h2, ($l1>$l2 ? $l1: $l2), $h1-1);
  warn "\$h1=$h1, \$h2=$h2, Vstacked: $h,$l,$b,0,$str1\n$str2\n__END__\n" if $debug & $debug_record;
  return "$h,$l,$b,0,$str1\n$str2";
} 

# Takes two records, returns a record that contains them and forms 
# SupSub block

sub superSub {
  local($h1,$l1,$b1,$sp1,$str1)=split(/,/,shift,5);
  local($h2,$l2,$b2,$sp2,$str2)=split(/,/,shift,5);
  $h1 || $h1++;
  $h2 || $h2++;
  local($h,$l)=($h1+$h2+1, ($l1>$l2 ? $l1: $l2));
  return "$h,$l,$h1,0,$str1\n\n$str2";
} 

# Takes two records, returns a record that contains them and forms 
# SupSub block

sub subSuper {
  local($h1,$l1,$b1,$sp1,$str1)=split(/,/,shift,5);
  local($h2,$l2,$b2,$sp2,$str2)=split(/,/,shift,5);
  $h1 || $h1++;
  $h2 || $h2++;
  local($h,$l)=($h1+$h2+1, ($l1>$l2 ? $l1: $l2));
  return "$h,$l,$h1,0,$str2\n\n$str1";
} 

# Takes the last two records, returns a record that contains them and forms 
# SupSub block

sub f_subSuper {
  warn "Entering f_subSuper...\n" if $debug & $debug_flow;  
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  &sup_sub(0,1);
} 

sub sup_sub {
  local($p1,$p2)=($#out-shift,$#out-shift);
  warn "Super $p1 $out[$p1]\nSub $p2 $out[$p2]\n__END__\n" if $debug & $debug_record;
  local($h1,$l1,$b1,$sp1,$str1)=split(/,/,$out[$p1],5);
  local($h2,$l2,$b2,$sp2,$str2)=split(/,/,$out[$p2],5);
  if ($l1==0 && $l2==0) {return;}
  $h1 || $h1++;
  $h2 || $h2++;
  local($h,$l)=($h1+$h2+1, ($l1>$l2 ? $l1: $l2));
  $#chunks--;
  $#out--;
  if ($l1==0) {
    $h2++;
    $out[$#out]="$h2,$l,0,0,\n$str2";
  } elsif ($l2==0) {
    $h=$h1+1;
    $out[$#out]="$h,$l,$h1,0,$str1\n";
  } else {
    $out[$#out]="$h,$l,$h1,0,$str1\n\n$str2";
  } 
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(2,1);
} 

# Takes the last two records, returns a record that contains them and forms 
# SupSub block

sub f_superSub {
  warn "Entering f_superSub...\n" if $debug & $debug_flow;  
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  &sup_sub(1,0);
} 

# digest \begin{...} and similar: handles argument to a subroutine
# given as argument

sub f_get1 {
  warn "Entering f_get1...\n" if $debug & $debug_flow;  
  (warn "Argument of f_get1 consists of 2 or more chunks", return)
      if $#out != $chunks[$#chunks];
  local($rec,$sub);
  #$rec=&uncommit;
  $rec=$out[$#out];
  $rec=~s/.*,//;
  $sub=shift;
  defined $sub ? return &$sub($rec): return $rec;
} 

sub f_begin {
  warn "Entering f_begin...\n" if $debug & $debug_flow; 
  &collapse(1);
  &assertHave(1) || &finish("");
  local($arg,$env)=(&f_get1());
  &finish_ignore(1);
  $arg=~s/^\s+//;
  $arg=~s/\s+$//;
  return if defined $environment_none{$arg};
  if (defined ($env=$environment{$arg})) {
    local($b,$e)=split(/,/,$env);
    for (split(":",$b)) {&callsub($_);}
  } else {&puts("\\begin{$arg}");}
} 

sub f_end {
  warn "Entering f_end...\n" if $debug & $debug_flow;
  &collapse(1);
  &assertHave(1) || &finish("");
  local($arg,$env)=(&f_get1());
  &finish_ignore(1);
  $arg=~s/^\s+//;
  $arg=~s/\s+$//;
  return if defined $environment_none{$arg};
  if (defined ($env=$environment{$arg})) {
    local($b,$e)=split(/,/,$env,2);
    for (split(":",$e)) {&callsub($_);}
  } else {&puts("\\end{$arg}");}
} 

sub f_newtheorem {
  warn "Entering f_newtheorem...\n" if $debug & $debug_flow;  
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  warn "Name `$out[$#out-1]'\nExpansion `$out[$#out]'\n__END__\n" if $debug & $debug_record;

  local($name, $expand) = ($out[$#out-1], $out[$#out]);
  $#out -= 2;
  $#chunks -= 2;
  return unless $name =~ s/^\d+,\d+.\d+,\d+,//;
  return unless $expand =~ s/^\d+,\d+.\d+,\d+,//;
  $environment{$name}="par:unindent:puts;$expand. ,par";
  &finish(2,1);
} 

sub f_newtheorem1 {
  warn "Entering f_newtheorem1...\n" if $debug & $debug_flow;  
  &trim(1);
  &collapse(1);
  &assertHave(1) || &finish("",1);
  warn "Name `$out[$#out]'\n__END__\n" if $debug & $debug_record;

  local($name) = ($out[$#out]);
  $#out -= 1;
  $#chunks -= 1;
  $par =~ s/^\[[^\]]*\]//;	# Optional argument 2
  return unless $name =~ s/^\d+,\d+.\d+,\d+,//;
  $last_newtheorem = $name;
  &finish(1,1);
} 

sub f_newtheorem2 {
  warn "Entering f_newtheorem2...\n" if $debug & $debug_flow;  
  &trim(2);
  &collapse(2);
  warn "Expansion `$out[$#out]'\n__END__\n" if $debug & $debug_record;

  local($expand) = ($out[$#out]);
  $#out -= 2;
  $#chunks -= 2;
  $par =~ s/^\[[^\]]*\]//;	# Optional argument 4
  return unless $expand =~ s/^\d+,\d+.\d+,\d+,//;
  $environment{$last_newtheorem} = "par:unindent:puts;$expand. ,par";
  &finish(2,1);
}

sub f_literal_no_length {
  warn "Entering f_literal_no_length...\n" if $debug & $debug_flow;
  # &trim(1);
  &collapse(1);
  &assertHave(1) || &finish("",1);
  record_forcelength($out[$#out], 0);
  &finish(1,1);
}

sub f_discard {
  warn "Entering f_discard...\n" if $debug & $debug_flow;
  &finish_ignore($wait[$#level]);
} 

# Takes a number and a record, returns a centered record

sub center {
  local($len,$left)=(shift,0);
        warn "Entering center, ll=$len, rec=$_[0]\n__ENDREC__\n" if $debug & $debug_flow;
  #$_[0]; # bug in perl?
  local($h1,$l1,$b1,$sp1,$str1)=split(/,/,$_[0],5);
  $h1 || $h1++;
  if (($left=$len-$l1)<=0) {return $_[0];}
  local($LHS,$RHS);
  $LHS = int($left/2); $RHS = $left - $LHS;
  local($out,$first)=("",1);
  for (split(/\n/,$str1,$h1)) {
    if ($first) {$first=0;}
    else {$out .= "\n";}
    $out .= " " x $LHS. $_ . " " x $RHS;
  } 
  return "$h1,$len,$b1,0,$out";
} 

# Example of radical
#<<'EOF';
# +--+
#\|12
#EOF
<<EOF;				# To hide HERE-DOC start above  from old CPerl
EOF

# Takes the last record, returns a record that contains it and forms 
# radical block

sub f_radical {
  warn "Entering f_radical...\n" if $debug & $debug_flow; 
  &trim(1);
  &collapse(1);
  &assertHave(1) || &finish("",1);
  warn "Radical of $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($h,$l,$b)=($out[$#out] =~ /^(\d+),(\d+),(\d+)/g);
  $h || $h++;
  local($out,$b1,$h1);
  $out=&vStack(&string2record(("-" x $l)."+" ),$out[$#out]);
  $b1=$b+1;
  $h1=$h+1;
  #$out =~ s/^(\d+,\d+,)(\d+)/\1$b1/;
  &setbaseline($out,$b1);
  $out[$#out]=&join("$h1,2,$b1,0, +\n" . (" |\n" x ($h-1)) . '\|',$out);
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(1,1);
} 

# Takes the last two records, returns a record that contains them and forms 
# fraction block

sub arrow_fraction {
  local($minlength, $l, $r, $flip) = @_;
  warn "Entering arrow_fraction, minlength=$minlength, left=$l, right=$r...\n" if $debug & $debug_flow;  
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  warn "Numer `$out[$#out-1]'\nDenom `$out[$#out]'\n__END__\n" if $debug & $debug_record;

  local($l1,$l2)=(&length($out[$#out-1]),&length($out[$#out]));
  local($len)=(($l1>$l2 ? $l1: $l2));
  $len = $minlength if $len < $minlength;
  local $line = $len <= 1? "-" : ($l . ("-" x ($len - 2)) . $r);

  if ($flip) {
    $out[$#out-1]=&vStack(&vStack(&center($len,$out[$#out]),
                           &string2record($line)),
                   &center($len,$out[$#out-1]));
  } else {
    $out[$#out-1]=&vStack(&vStack(&center($len,$out[$#out-1]),
                           &string2record($line)),
                   &center($len,$out[$#out]));
  }
  $#chunks--;
  $#out--;
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(2,1);
} 

sub f_fraction {
  arrow_fraction(1,"-","-");
} 

sub f_right_arrow {
  arrow_fraction(3,"-",">",1);
} 

sub f_left_arrow {
  arrow_fraction(3,"<","-",1);
} 

# Takes the last two records, returns a record that contains them and forms 
# fraction block

sub f_overset {
  warn "Entering f_overset...\n" if $debug & $debug_flow;  
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  warn "Over `$out[$#out-1]'\nBase `$out[$#out]'\n__END__\n" if $debug & $debug_record;
  local($l1,$l2)=(&length($out[$#out-1]),&length($out[$#out]));
  local($len)=(($l1>$l2 ? $l1: $l2));

  local($b, $b1)=($out[$#out] =~ /^\d+,\d+,(\d+)/);
  ($b1)=($out[$#out-1] =~ /^(\d+)/);
  $b1 ||= 1;				# height=0 means 1!
  $b += $b1;
  $out[$#out-1]=&vStack(&center($len,$out[$#out-1]),           
	                &center($len,$out[$#out]));                          
  $#chunks--;
  $#out--;
  &setbaseline($out[$#out],$b);
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(2,1);
} 

sub f_choose {
  warn "Entering f_choose...\n" if $debug & $debug_flow;  
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  warn "Numer `$out[$#out-1]'\nDenom `$out[$#out]'\n__END__\n" if $debug & $debug_record;
  local($l1,$l2)=(&length($out[$#out-1]),&length($out[$#out]));
  local($len)=(($l1>$l2 ? $l1: $l2));
  $out[$#out]=&vStack(&vStack(&center($len,$out[$#out-1]),                 
                         &string2record(" " x $len)),           
                 &center($len,$out[$#out]));                          
  $#chunks++;
  $#out++;
  #warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  $out[$#out - 2] = &string2record("(");
  $out[$#out] = &string2record(")");
  local($h,$b)=($out[$#out-1] =~ /^(\d+),\d+,(\d+)/)[0,1];
  &makehigh($out[$#out-2],$h,$b,0,1);
  &makehigh($out[$#out],$h,$b,1,0);
  &finish(2,1);
}


sub f_buildrel {
        warn "Entering f_buildrel...\n" if $debug & $debug_flow;
  &trim(3);
        &collapse(3);
        &assertHave(3) || &finish("",1);
        warn "What: $out[$#out-2]\nOver $out[$#out]\n__END__\n" if $debug & $debug_record;
        local($rec)=($out[$#out-2]);
        $out[$#out-2]=$out[$#out];
        $#chunks-=2;
        $#out-=2;
  &f_putover($rec,1);
        warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
        &finish(3,1);
}

# Takes two records, returns a record that contains them and forms a
# fraction block

sub fraction {
  local($l1,$l2)=(&length($_[0]),&length($_[1]));
  local($len)=(($l1>$l2 ? $l1: $l2));
  return &vStack(&vStack(&center($len,shift),                 
                         &string2record("-" x $len)),           
                 &center($len,shift));                          
} 

# Commits a given string

sub puts {
  &commit(&string2record);
} 

# digests an eaten paragraph

$ending = 0;

sub end_TeX {
  $par = '';
  $ending = 1;
}

sub paragraph {
  local($par);
  return 0 if $ending;
  $par=<>;
  return 0 unless defined $par;
  return 1 unless $par =~ /\S/;			# whitespace only
  print "\n" if $secondtime++ && !$opt_by_par;
  #$par =~ s/(^|[^\\])%.*\n[ \t]*/\1/g;
  $par =~ s/((^|[^\\])(\\\\)*)(%.*\n[ \t]*)+/\1/g;
  $par =~ s/\n\s*\n/\\par /g;
  $par =~ s/\s+/ /g;
  $par =~ s/\s+$//;
  $par =~ s/(\$\$)\s+/\1/g;
  $par =~ s/\\par\s*$//;
  local($defcount,$piece,$pure,$type,$sub,@t,$arg)=(0);
  &commit("1,5,0,0,     ")
    unless $opt_noindent || ($par =~ s/^\s*\\noindent\s*([^a-zA-Z\s]|$)/\1/);
  while ($tokenByToken[$#level] ?
      ($par =~ s/^\s*($tokenpattern)//o): ($par =~ s/^($multitokenpattern)//o)) {
    warn "tokenByToken=$tokenByToken[$#level], eaten=`$1'\n"  
        if $debug & $debug_parsing;
    if (($piece=$1) =~ /^$usualtokenclass/o) {
      # plain piece
      &puts($piece);
    } else {
      # macro or delimiter
      ($pure = $piece);
      if ($pure =~ /^\\\s+$/) {
        $pure =~ s/(\\\s)\s+$/$1/;
      } else {
        $pure =~ s/\s+$//;
      }
      if (defined ($type=$type{$pure})) {
        if ($type eq "def") {
          warn "To many def expansions in a paragraph" if $defcount++==$maxdef;
          last if $defcount>$maxdef;
          @t=(0);
          for (1..$args{$pure}) {
            push(@t,&get_balanced());
          }
          warn "Defined token `$pure' found with $args{$pure} arguments @t[1..$#t]\n"
          if $debug & $debug_parsing;
          $sub=$def{$pure};
          $sub =~ s/(^|[^\\#])#(\d)/$1 . $t[$2]/ge if $args{$pure};
          $par=$sub . $par;
        } elsif ($type eq "sub") {
          $sub=$contents{$pure};
          index($sub,";")>=0?
            (($sub,$arg)=split(";",$sub,2), &$sub($pure,$arg)):
              &$sub($pure);
        } elsif ($type =~ /^sub(\d+)$/) {
	  local($n) = $1;
          $sub=$contents{$pure};	  
	  if ($sub =~ s/^\[\]//) {
            if ($par =~ /^\[/) {
              $par =~ s/^\[([^\]]*)\]/{$1}/;
            } else {
              substr($par, 0, 0) = "{}";
            }
          }
          &start($n,"f_$sub");
          $tokenByToken[$#level]=1;
        } elsif ($type =~ /^get(\d+)$/) {
          &start($1+1);
          &puts($piece);
          $tokenByToken[$#level]=1;
        } elsif ($type =~ /^discard(\d+)$/) {
          &start($1,"f_discard");
          $tokenByToken[$#level]=1;
        } elsif ($type eq "record") {
          &commit($contents{$pure});
        } elsif ($type eq "self") {
          &puts(substr($pure,1) . ($pure =~ /^\\[a-zA-Z]/ ? " ": ""));
        } elsif ($type eq "par_self") {
          &finishBuffer;
          &commit("1,5,0,0,     ");
                &puts($pure . ($pure =~ /^\\[a-zA-Z]/ ? " ": ""));
        } elsif ($type eq "self_par") {
          &puts($pure . ($pure =~ /^\\[a-zA-Z]/ ? " ": ""));
          &finishBuffer;
          &commit("1,5,0,0,     ")
            unless $par =~ s/^\s*\\noindent(\s+|([^a-zA-Z\s])|$)/\2/;
        } elsif ($type eq "string") {
          &puts($contents{$pure},1);
        } elsif ($type eq "nothing") {
        } else {
          warn "Error with type `$type' while interpreting `$pure'";
        } 
      } else {
        &puts($piece);
      } 
    } 
  }
  warn "Unrecognized part of input `$par',\n\ttoken-by-token[$#level]=$tokenByToken[$#level]" 
    if $par ne "";   
  &finishBuffer if $#out>=0;
# return 0 if eof();
  1;
} 

sub subscript {
  &start(1,"f_subscript");
  $tokenByToken[$#level]=1;
}

sub superscript {
  &start(1,"f_superscript");
  $tokenByToken[$#level]=1;
}


sub f_subscript {
  $wait[$#level]=2;
  $action[$#level]="f_subSuper";
  if (($par !~ s/^\s*\^//) &&
      ($par !~ s:^\s*\\begin\s*\{Sp\}:\\begin\{matrix\}:)) {
    &commit(&empty);
  }   
} 

sub f_overline {
  warn "Entering f_overline...\n" if $debug & $debug_flow;  
  &trim(1);
  &collapse(1);
  &assertHave(1) || &finish("",1);
  warn "Overlining $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($h,$len,$b)=($out[$#out] =~ /^(\d+),(\d+),(\d+)/);
  $out[$#out]=&vStack(&string2record("_" x $len),
                      $out[$#out]);
  $b++;
  #$out[$#out] =~ s/^(\d+,\d+,)(\d+)/\1$b/;
  &setbaseline($out[$#out],$b);
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(1,1);
} 

sub f_underline {
  warn "Entering f_underline...\n" if $debug & $debug_flow; 
  &trim(1);
  &collapse(1);
  &assertHave(1) || &finish("",1);
  warn "Underlining $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($h,$len,$b)=($out[$#out] =~ /^(\d+),(\d+),(\d+)/);
  $out[$#out]=&vStack($out[$#out],&string2record("_" x $len));
  #$out[$#out] =~ s/^(\d+,\d+,)(\d+)/\1$b/;
  &setbaseline($out[$#out],$b);
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(1,1);
} 

sub f_not {
  warn "Entering f_not...\n" if $debug & $debug_flow;  
  &collapse(1);
  &assertHave(1) || &finish("",1);
  warn "Negating $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($str)=(split(/,/,$out[$#out]))[4];
  if ($str eq "=") {
    $out[$#out]=$contents{"\\neq"};
  } elsif ($str =~ /^\s*\|\s*$/) {
    $out[$#out]=$contents{"\\nmid"};
  } elsif ($out[$#out] eq $contents{"\\in"}) {
    $out[$#out]=$contents{"\\notin"};
  } else {
    $out[$#out]=&join(&string2record("\\not"),$out[$#out]);
  }
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(1,1);
} 

sub f_putunder {
  warn "Entering f_putunder...\n" if $debug & $debug_flow;
  &trim(1);
  &collapse(1);
  &assertHave(1) || &finish("",1);
  warn "Putting Under $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($h,$len,$b)=($out[$#out] =~ /^(\d+),(\d+),(\d+)/);
        local($l2)=(&length($_[0]));
        local($len)=(($l1>$l2 ? $l1: $l2));
  $out[$#out]=&vStack(&center($len,$out[$#out]),&center($len,shift));
  #$out[$#out] =~ s/^(\d+,\d+,)(\d+)/\1$b/;
  &setbaseline($out[$#out],$b);
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(1,1);
}

# if has additional true argument will not finish
# Takes record to put over

sub f_putover {
  warn "Entering f_putover...\n" if $debug & $debug_flow; 
  &trim(1);
  &collapse(1);
  &assertHave(1) || &finish("",1);
  warn "Putting Over $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($h,$l1,$b,$b1)=($out[$#out] =~ /^(\d+),(\d+),(\d+)/);
        local($l2)=(&length($_[0]));
        local($len)=(($l1>$l2 ? $l1: $l2));
  ($b1)=($_[0] =~ /^(\d+)/);
  $b1 ||= 1;				# height=0 means 1!
  $b+=$b1;
  $out[$#out]=&vStack(&center($len,shift),&center($len,$out[$#out]));
  #$out[$#out] =~ s/^(\d+,\d+,)(\d+)/\1$b/;
  &setbaseline($out[$#out],$b);
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(1,1) unless shift;
} 

sub f_putpar {
        warn "Entering f_putpar...\n" if $debug & $debug_flow;
  &trim(1);
  local($l,$r)=split(";",shift);
        &collapse(1);
        &assertHave(1) || &finish("",1);
        warn "Putting Parentheses $out[$#out]\n__END__\n" if $debug & $debug_record;
  $out[$#out]=&join(&string2record($l),
      &join($out[$#out],&string2record($r)));
  &finish(1);
}

sub f_putover_string {
  &f_putover(&string2record);
} 

sub f_putunder_string {
  &f_putunder(&string2record);
} 

sub f_widehat {
        &trim(1);
  &collapse(1);
        local($l)=(&length($out[$#out]));
        if ($l<=1) {&f_putover(&string2record("^"));}
        else {&f_putover(&string2record("/" . "~" x ($l-2) . "\\"));}
}

sub f_widetilde {
  &trim(1);
  &collapse(1);
  local($l,$l1)=(&length($out[$#out]));
  if ($l<=1) {&f_putover(&string2record("~"));}
  elsif ($l<=3) {&f_putover(&string2record("/\\/"));}
  else {&f_putover(&string2record("/" . "~" x ($l1=int($l/2-1)) .
     "\\" . "_" x ($l-3-$l1) . "/"));}
}

sub f_underbrace {
  &trim(1);
  &collapse(1);
  local($l,$l1)=(&length($out[$#out]));
  if ($l < 5) { $l = 5 }
  &f_putunder(vStack(&string2record("\\" . "_" x ($l1=int($l/2-1)) . " "
				    . "_" x ($l-3-$l1) . "/"),
		     &string2record(" " x ($l1=int($l/2)) . "v"
				    . " " x ($l-2-$l1))));
}

sub f_underbrace2 {
  &trim(2);
  &collapse(2);
  local($l,$l1)=(&length($out[$#out - 1]));
  if ($l < 5) { $l = 5 }
  local($b)=($out[$#out - 1] =~ /^\d+,\d+,(\d+)/);
  $out[$#out-1]
    = &vStack(&center($l,$out[$#out-1]),
	      vStack(vStack(&string2record("\\" . "_" x ($l1=int($l/2-1)) . " "
					   . "_" x ($l-3-$l1) . "/"),
			    &string2record(" " x ($l1=int($l/2)) . "v"
					   . " " x ($l-2-$l1))),
		     &center($l,$out[$#out])));
  $#chunks--;
  $#out--;
  &setbaseline($out[$#out],$b);
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(2,1);
}

sub f_overbrace {
  &trim(1);
  &collapse(1);
  local($l)=(&length($out[$#out]));
  if ($l < 6) { $l = 6 }
  local($l1) = int($l/2);
  &f_putover(vStack(&string2record(" " . "_" x ($l1 - 2) . "/\\"
				    . "_" x ($l-2-$l1) . " "),
		    &string2record("/" . " " x ($l1 - 2) . "  "
				    . " " x ($l-2-$l1) . "\\"),
		    ));
}

sub f_overbrace2 {
  &trim(2);
  &collapse(2);
  local($l)=(&length($out[$#out - 1]));
  if ($l < 5) { $l = 5 }
  local($h,$b)=($out[$#out - 1] =~ /^(\d+),\d+,(\d+)/);
  $h ||= 1;
  local($l1) = int($l/2);
  $out[$#out-1]
    = &vStack(vStack(&center($l,$out[$#out]),
		     vStack(&string2record(" " . "_" x ($l1 - 2) . "/\\"
					   . "_" x ($l-2-$l1) . " "),
			    &string2record("/" . " " x ($l1 - 2) . "  "
					   . " " x ($l-2-$l1) . "\\"))),
	      &center($l,$out[$#out-1]));
  $#chunks--;
  $#out--;
  local($h1) = ($out[$#out] =~ /^(\d+),/);
  &setbaseline($out[$#out], $h1 - ($h - $b));
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(2,1);
}

sub f_superscript {
  $wait[$#level]=2;
  $action[$#level]="f_superSub";
  if (($par !~ s/^\s*\_//) &&
      ($par !~ s:^\s*\\begin\s*\{Sb\}:\\begin\{matrix\}:)) {
    &commit(&empty);
  }   
}

sub let {
        $par =~ s/^($tokenpattern)(= ?)?($tokenpattern)//o;
}

sub let_exp {
        $par =~ s/^($tokenpattern)(= ?)?($tokenpattern)//o;
  return if index($&,'@')>=0;
  local($what)=$1;
  $type{$what}='def';
  $& =~ /($tokenpattern)$/;
  $def{$what}=$1;
  $args{$what}=0;
        warn "Definition of `$what' with $args{$what} args is `$def{$what}'\n"
                        if $debug & $debug_parsing;
}


sub def {
  $par =~ s/^[^{]*//;
  &start(1,"f_discard");
  $tokenByToken[$#level]=1;
}

sub def_exp {
  return unless $par =~ s:^(([^\\{]|\\.)*)\{:\{:;
  local($arg)=($1);
  local($def,$act)=(&get_balanced());
  return unless defined $def;
  return if index("$arg$def",'@')>=0;
  return if $def =~ /\\([egx]?def|fi)([^a-zA-Z]|$)/;
  $def .= " "  if $def =~ /($macro)$/o;
  &define($arg,$def);
}

sub def_exp_block {
  return unless $par =~ s:\{(\\([a-zA-Z]+|.))\}\{:\{:;
  local($arg)=($1);
  local($def,$act)=(&get_balanced());
  return unless defined $def;
  return if index("$arg$def",'@')>=0;
  return if $def =~ /\\([egx]?def|fi)([^a-zA-Z]|$)/;
  $def .= " "  if $def =~ /($macro)$/o;
  &define($arg,$def);
}

# Arguments: Token . Parameters, Expansion

sub define {
  local($arg,$def,$act)=(shift,shift);
  return unless $arg =~ /^($active)/o;
  $act=$1;
  $args{$act}=$';
  return unless $args{$act} =~ /^(#\d)*$/;
  $args{$act}=length($args{$act})/2;
  $def{$act}=$def;
  $type{$act}='def';
  warn "Definition of `$act' with $args{$act} args is `$def'\n"
      if $debug & $debug_parsing;
}

sub defb {
  for (@_) {
    &define("\\$_","\\begin{$_}");&define("\\end$_","\\endTeXtoMail{$_}");
  }
}

# Discards surrounding {}

sub get_balanced {
        return undef unless $par =~ s/^($tokenpattern)//;
  return $1 unless $1 eq '{';
        local($def,$lev)=('',1);
        while ($lev) {
                last unless $par =~ s/^[^\\{}]|\\.|[{}]//;
                $lev++ if $& eq '{';
                $lev-- if $& eq '}';
                $def .= $& if $lev;
        }
        (warn "Balanced text not finished!",return undef) if $lev;
        return $def;
}


sub open_curly {
  #&puts("{") unless $tokenByToken[$#level];
  &start("}");
}

# Deletes extra spaces at the end of a record

sub trim_end {
  local($h,$str)=(split(/,/,$_[0],5))[0,4];
  if (!$h) {
    $str =~ s/\s+$//;
    $_[0]=&string2record($str);
    warn "Trimmed End `$_[0]'\n__END__\n" if $debug & $debug_record;
  }
}

# Deletes extra spaces at the beginning of a record

sub trim_beg {
  local($h,$str)=(split(/,/,$_[0],5))[0,4];
  if (!$h) {
    $str =~ s/^\s+//;
    $_[0]=&string2record($str);
    warn "Trimmed Beg `$_[0]'\n__END__\n" if $debug & $debug_record;
  }
}

# Deletes extra spaces at the ends of a chunk with given number

sub trim_one {
  &trim_beg($out[$chunks[$_[0]]]);
  &trim_end($_[0]==$#chunks? $out[$#out]: $out[$chunks[$_[0]+1]-1]);
}

# Deletes extra spaces at the ends of a given number of chunks

sub trim {
  for ($#chunks-$_[0]+1..$#chunks) {&trim_one($_);}
}

sub dollar {
  if ($wait[$#level] eq '$') {        # ';
    &trim_end($out[$#out]);
    &finish('$');
  }
  else {
    &start('$');
    $par =~ s/^\s+//;
  }
} 

sub ddollar {
  if ($wait[$#level] eq '$$') {
    &trim_end($out[$#out]);
    &finish('$$');
    return unless $#out>=0;
    $#chunks=0;
    $chunks[0]=0;
    &trim(1);
    &collapse(1);
    &printrecord(&center($linelength,$out[0]));
    @level=(0);
    @chunks=(0);
    @tokenByToken=(0);
    @out=();
    $curlength=0;
    # Maybe after \begin{align}
  }
  else {
    &finishBuffer;
    &start('$$');
  }
  $par =~ s/^\s+//;
}

sub item {
  &finishBuffer;
  # To make unexpandable:
  &commit("1,11,0,0,     (\@)   ");
}

sub bbackslash {
  if ($wait[$#level] eq '$$') {
    &ddollar();
    &ddollar();
  } elsif ($wait[$#level] eq 'endCell') {
    return if $par =~ /^\s*\\end/;		# Ignore the last one
    &finish('endCell', 1);
    &trim(1);
    &collapse(1);
    &finish('endRow', 1);
    &start('endRow');
    &start('endCell');
  } else {
    #&puts(" \\\\ ");
    &par;
  }
}

sub ampersand {
  if ($wait[$#level] eq 'endCell') {
    &finish('endCell',1);
    &trim(1);
    &collapse(1);
    &start('endCell');
  } 
}

sub matrix {
  &start('endMatrix');
  &start('endRow');
  &start('endCell');
}

sub endmatrix {
  &finish('endCell',1);
  &trim(1);
  &collapse(1);
  &finish('endRow',1);
  # Now chunks correspond to rows of the matrix, records inside chunks to 
  # Cells
  &halign(split(";",shift));
  &finish('endMatrix',1);
}

sub endmatrixArg {
  my $aspec = pop(@argStack);
  # Replace *{20}{c} by "c" x 20; same for omited {}.
  $aspec =~ s/\*(?:\{(\d+)\}|([^{]))(?:\{(.*?)\}|([^{]))/
	(defined($1) ? $1 : $2) x (defined($3) ? $3 : $4) /eg;
  &endmatrix(join(";",($_[0],split("", $aspec))));
}

# Takes a matrix in the following form: chunks on the last level
# are row of the matrix, records inside chunks are cells.
# Puts the resulting matrix in the first record on the given level 
# and truncates the rest

# I'm trying to add parameters: 
#	length to insert between columns
#	Array of centering options one for a column (last one repeated if needed)
#		Currently supported:	c for center
#					r for right
#					l for left

sub halign {
  local($explength)=(shift);
  local(@c)=@_;
  local($last,$le,$b,$h);
  local(@w)=();
  #warn "levels @level, chunks @chunks, records @out\n";
  # Find metrics of cells
  for $r (0..$#chunks-$level[$#level]) {
    $last= ($r==$#chunks-$level[$#level]) ? $#out:
                                            $chunks[$r+1+$level[$#level]]-1;
  warn "Row $r: last column " . ($last-$chunks[$r+$level[$#level]]) ."\n"
                                if $debug & $debug_matrix;
    for $c (0..$last-$chunks[$r+$level[$#level]]) {
      ($h,$le,$b)=
                ($out[$chunks[$r+$level[$#level]]+$c] =~ /(\d+),(\d+),(\d+)/);
        # Format is Height:Length:Baseline
      $w[$c]=$le unless $w[$c]>$le;
    }
  }
  # expand the height and depth
  for $c (0..$#w-1) {$w[$c]+=$explength;}
  # Extend the @c array by the last element or "c" if it is empty
  @c=("c") x @w unless @c;
  @c=(@c,($c[$#c]) x (@w-@c));
  # Now expand the cells
  warn "Widths of columns @w\n" if $debug & $debug_matrix;
  for $r (0..$#chunks-$level[$#level]) {
    $last= ($r==$#chunks-$level[$#level]) ? $#out: 
                                            $chunks[$r+1+$level[$#level]]-1;
    warn "Row $r: last column " . ($last-$chunks[$r+$level[$#level]]) ."\n"
        if $debug & $debug_matrix;
    for $c (0..$last-$chunks[$r+$level[$#level]]) {
      if ($c[$c] eq "c") {
        warn "Centering row $r col $c to width $w[$c]\n"
            if $debug & $debug_matrix;
        $out[$chunks[$r+$level[$#level]]+$c]=
          &center($w[$c],$out[$chunks[$r+$level[$#level]]+$c]);
      } elsif ($c[$c] eq "l") {
        warn "Expanding row $r col $c to width $w[$c]\n"
            if $debug & $debug_matrix;
        $out[$chunks[$r+$level[$#level]]+$c]=
          &join($out[$chunks[$r+$level[$#level]]+$c],
                &string2record(" " x 
                  ($w[$c] - &length($out[$chunks[$r+$level[$#level]]+$c]))));
      } elsif ($c[$c] eq "r") {
        warn "Expanding row $r col $c to width $w[$c] on the left\n"
            if $debug & $debug_matrix;
        $out[$chunks[$r+$level[$#level]]+$c]=
          &join(&string2record(" " x
                  ($w[$c]-$explength- 
                       &length($out[$chunks[$r+$level[$#level]]+$c]))),
                $out[$chunks[$r+$level[$#level]]+$c]);
        $out[$chunks[$r+$level[$#level]]+$c]=
          &join($out[$chunks[$r+$level[$#level]]+$c],
                &string2record(" " x $explength));
      } else {warn "Unknown centering option `$c[$c]' for halign";}
    } 
  }
  # Now we creat rows
  &collapseAll;
  # And stack them vertically
  for ($chunks[$level[$#level]]+1..$#out) {
    $out[$chunks[$level[$#level]]]=&vStack($out[$chunks[$level[$#level]]],
                                           $out[$_]);
  }
  &setbaseline($out[$chunks[$level[$#level]]],
               int((&height($out[$chunks[$level[$#level]]])-1)/2));
  $#chunks=$level[$#level];
  $#out=$chunks[$level[$#level]];
}

sub close_curly {
  &finish("}");
  #&puts("}") unless $tokenByToken[$#level]; # well, this can change under our foot...
} 

sub at {
  local($c,$first,$second,$t,$m)=($par =~ /^(.)/);
  if ($c eq '@') {&puts('@');$par =~ s/^.//;}
  elsif (index("<>AV",$c)>=0) {
    $m="&" if ($wait[$#level] eq 'endCell');
    $m="&&" if $m eq "&" && index("AV",$c)>=0;
    &ampersand if $m eq "&";
    $par =~ s/^.//;
    $first=$second="";
    while (($t=&get_balanced()) ne $c && defined $t) {
      $first .= $t;
    }
    while (($t=&get_balanced()) ne $c && defined $t) {
      $second .= $t;
    }
    $par="{$first}{$second}$m" . $par;
    local($l,$r);
    ($l=$c) =~ tr/A>V/^/d;
    ($r=$c) =~ tr/<A//d;
    index("<>",$c)>=0 ?
       &start(2,"f_arrow;$l;$r"):
       &start(2,"f_arrow_v;$l;$r");
  }
  elsif ($c eq "." && $wait[$#level] eq 'endCell') {
    &ampersand;
    &ampersand;
    $par =~ s/^.//;
  }
  else {&puts('@');}
}

# takes two tips of arrow as argument separated by ";",
# we assume that total length is 1

sub f_arrow {
  warn "Entering f_arrow...\n" if $debug & $debug_flow;
  local($l,$r)=split(";",shift);
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  warn "Over: $out[$#out-1]\nUnder: $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($l1,$l2)=(&length($out[$#out-1]),&length($out[$#out]));
  local($len)=(($l1>$l2 ? $l1: $l2));
  $out[$#out-1]=&vStack(&vStack(&center($len+4,$out[$#out-1]),
                         &string2record(" $l" ."-" x ($len+1) . "$r ")),
                 &center($len+4,$out[$#out]));
  $#chunks--;
  $#out--;
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(2,1);
}

# takes two tips of arrow as argument separated by ";",
# we assume that total length is 1

sub f_arrow_v {
  warn "Entering f_arrow_v...\n" if $debug & $debug_flow;
  local($l,$r)=split(";",shift);
  &trim(2);
  &collapse(2);
  &assertHave(2) || &finish("",1);
  warn "Over: $out[$#out-1]\nUnder: $out[$#out]\n__END__\n" if $debug & $debug_record;
  local($h1,$b1)=($out[$#out-1] =~ /^(\d+),\d+,(\d+)/);
  local($h2,$b2)=($out[$#out] =~ /^(\d+),\d+,(\d+)/);
  local($b)=(($b1>$b2 ? $b1: $b2));
  local($res)=(&join($out[$#out-1],$out[$#out]));
  local($h,$bb)=($res =~ /^(\d+),\d+,(\d+)/);
  $bb=$b+1;
  $out[$#out-1]=&vStack(&vputs(" " x ($b-$b1+1)),
                        $out[$#out-1]);
  #$out[$#out-1] =~ s/^(\d+,\d+,)(\d+)/\1$bb/;
  &setbaseline($out[$#out-1],$bb);
  $out[$#out]=&vStack(&vputs(" " x ($b-$b2+1)),
                                     $out[$#out]);
  #$out[$#out] =~ s/^(\d+,\d+,)(\d+)/\1$bb/;
  &setbaseline($out[$#out],$bb);
  $out[$#out-1]=&join(&join($out[$#out-1],
                         &vputs($l ."|" x ($h+1) . $r,$b+1)),
                      $out[$#out]);
  $#chunks--;
  $#out--;
  warn "a:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
  &finish(2,1);
}

sub noindent {
  if ($#out == 0 && $#chunks == 0 && $out[$#out] eq '1,5,0,0,     ') {
    $#out--;
    $#chunks--;
  } else {
    &puts('\\noindent');
  }
}

# put strings vertically, returns a record with the second argument as baseline 

sub vputs {
  local($b)=($_[1]);
  $b=0 unless defined $b;
  return length($_[0]) . ",1,$b,0," . join("\n",split('',$_[0]));
}

sub choose {
  if ($wait[$#level] eq '}') {
    local($prevw)=($wait[$#level-1]);
    $wait[$#level-1]="junk";
    &finish("}",1);
          &collapse(1);
          &assertHave(1) || &finish("",1);
    local($rec)=$out[$#out];
    $#out--;
    $#chunks--;
    &start(2,"f_choose");
    $wait[$#level-1]=$prevw;
    &start("}");
    &commit($rec);
    &finish("}",1);
    &start("}");
  } else {&puts("\\choose");}
}

sub over {
  if ($wait[$#level] eq '}') {
    local($prevw)=($wait[$#level-1]);
    $wait[$#level-1]="junk";
    &finish("}", 1);
    &collapse(1);
    warn "X:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
    &assertHave(1) || &finish("",1);
    warn "Y:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
    local($rec)=$out[$#out];
    $#out--;
    $#chunks--;
    warn "Z:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
    &start(2,"f_fraction");
    $wait[$#level-1]=$prevw;
    &start("}");
    &commit($rec);
    &finish("}",1);
    &start("}");
  } else {&puts("\\over");}
}

# Takes a record, height, baseline, spaces_toleft and _toright
# and makes this record this high

sub makehigh {
  local($str)=(split(",",$_[0],5))[4];
  local($h,$b,$d)=($_[1],$_[2]+1);
  warn "Entering makehigh(@_)\n" if $debug & $debug_flow;
  if ($str eq ".") {$_[0] =~ s/\.$/ /;return;}
  #$str="<" if $str eq "\\langle";
  #$str=">" if $str eq "\\rangle";
  $h=1 unless $h;
  $d=$h-$b;
  return if $h<2 || $h==2 && index("()<>",$str)>=0;
  local(@c);
  if    ($str eq "(") {@c=split(":",'(: :|:/:\:|');}
  elsif ($str eq ")") {@c=split(":",'): :|:\:/:|');}
  elsif ($str eq "{") {@c=split(":",'{: :|:/:\:<');}
  elsif ($str eq "}") {@c=split(":",'}: :|:\:/:>');}
  elsif ($str eq "|" && $str eq "||") 
                      {@c=split(":",'|:|:|:|:|:|');}
  elsif ($str eq "[") {@c=split(":",'[:[:|:[:[:|');}
  elsif ($str eq "]") {@c=split(":",']:]:|:]:]:|');}
  elsif ($str eq "<" || $str eq ">") {
    return if $h==2;
    local($l)=($b);
    $l=$d+1 if $b<$d+1;
    for (2..$l) {
      $_[0]=&join($_[0],
                  &vputs("/" . " " x (2*$_-3) . "\\",$_-1)) if $str eq "<";
      $_[0]=&join(&vputs("\\" . " " x (2*$_-3) . "/",$_-1),
                  $_[0]) if $str eq ">";
    }
    $_[0]=&join($_[0],&string2record(" ")) if $str eq "<";
    $_[0]=&join(&string2record(" "),$_[0]) if $str eq ">";
    return;
  }
  else {return;}
  $_[0]=&vputs(&makecompound($b,$d,@c),$b-1);
  $_[0]=&join($_[0],$_[0]) if length($str)==2;
  $_[0]=&join(&string2record(" " x $_[3]),$_[0]) if $_[3];
  $_[0]=&join($_[0],&string2record(" " x $_[4])) if $_[4];
}

sub f_FOOTNOTE {
  &finish(1);
  puts(">>> ");
}

sub footnote {
  puts("<<<FOOTNOTE: ");
  &start(1, "f_FOOTNOTE");
  $tokenByToken[$#level]=1;
}

sub right {
  close_curly();
  &finish("LeftRight",1);
  &trim(1);
  &collapse(1);
}

sub f_left {
  &trim(1);
  &collapse(1);
  &finish(1);
  &start("LeftRight");
  open_curly();			# Fake a {}-group for \over etc.
}

sub left {
  &start(3,"f_leftright");
  $tokenByToken[$#level]=1;
  &start(1,"f_left");
  $tokenByToken[$#level]=1;
}

sub f_leftright_go {
  &trim(1);
  &collapse(1);
  local($l,$r)=split(";",shift);
  &assertHave(1) || warn "Left-Right not balanced";
  local($rec)=($out[$#out]);
  $#out--;
  $wait[$#level]="junk";
  &start(3,"f_leftright");
  &puts($l);
  &commit($rec);
  &puts($r);
  &finish("junk");
}

# Used to put \left SOMETHING \right SOMETHING around a group
sub beg_lr {
  &start(1,"f_leftright_go" . ";" . shift);
  $tokenByToken[$#level]=1;
}

sub f_leftright {
  &trim(1);
  &collapse(1);
  &assertHave(3) || warn "Left-Right not balanced";
  local($h,$b)=($out[$#out-1] =~ /^(\d+),\d+,(\d+)/)[0,1];
  &makehigh($out[$#out-2],$h,$b,0,1);
  &makehigh($out[$#out],$h,$b,1,0);
  &finish(3);
}

sub today {
  &puts(scalar localtime);
}

sub unindent {
# a:Last chunk number 0, last record 0, the first chunk
#  on the last level=0 is 0, waiting for
#    warn "B:Last $#chunks, the first on the last level=$#level is $level[$#level]" if $debug & $debug_flow;
   # Silently ignore failures (XXXX sometimes $#chunks is 0, sometimes 1?!)
   unless ($#chunks <= 1 && $#level == 0 && $level[$#level] == 0
           && $#out == 0 && $out[0] eq "1,5,0,0,     " && $curlength == 5) {
     return;
   }
   $out[0] = "1,0,0,0,";
   $curlength = 0;
}

sub puts_unindent {
  unindent();
  puts($_[1]);
}

sub par_puts_unindent {
  par();
  unindent();
  puts($_[1]);
}

# Arguments: Ascent, descent, base string, oneside expander, real expander
#            0       1        2            3                 4
#            Top tip, Bottom tip, Mid
#            5        6           7
# All component should be one character long

sub makecompound {
  # If Mid is the same as real expander, all depends on the height only
  # if there is extend on both sides
  # If it is 3 or more
  if ($_[0]>1 && $_[1]>0 && $_[4] eq $_[7]) {
    return $_[5] . $_[4] x ($_[0]+$_[1]-2) . $_[6];
  }
  # No descent:
  if ($_[1] <= 0) {return $_[3] x ($_[0]-1) . $_[2];}
  # No ascent:
  if ($_[0] <= 1) {return $_[2] . $_[3] x $_[1];}
  local($mid,$asc,$des)=($_[2]);
  # descent == 1
  $des = ($_[1]==1) ? $_[2]: $_[4] x ($_[1]-1) . $_[6];
  $asc  = ($_[0]==2) ? $_[2]: $_[5] . $_[4] x ($_[0]-2);
  $mid = $_[7] unless $_[0]==2 || $_[1]==1;
  return "$asc$mid$des";
}

sub arg2stack {push(@argStack,&get_balanced());}

sub par {&finishBuffer;&commit("1,5,0,0,     ")
	   unless $par =~ s/^\s*\\noindent\s*(\s+|([^a-zA-Z\s])|$)/\2/;}

$type{"\\sum"}="record";
$contents{"\\sum"}="3,4,1,0," . <<'EOF';
\~~   
 >
/__ 
EOF

$type{"\\int"}="record";
$contents{"\\int"}="3,3,1,0," . <<'EOF';
 ,-
 |
-'
EOF

$type{"\\prod"}="record";
$contents{"\\prod"}="3,3,1,0," . <<'EOF';
___
| |
| |
EOF

$type{"\\Pi"}="record";
$contents{"\\Pi"}="2,3,1,0," . <<'EOF';
 _
| |
EOF

$type{"\\Sigma"}="record";
$contents{"\\Sigma"}="3,2,1,0," . <<'EOF';
__
>
~~
EOF

$type{"\\Delta"}="record";
$contents{"\\Delta"}="2,2,0,0," . <<'EOF';
/\
~~
EOF

$type{"\\nabla"}="record";
$contents{"\\nable"}="2,2,1,0," . <<'EOF';
__
\/
EOF

$type{"\\oplus"}="record";
$contents{"\\oplus"}="3,5,1,0," . <<'EOF';
  _ 
 (+)
  ~
EOF

$type{"\\otimes"}="record";
$contents{"\\otimes"}="3,5,1,0," . <<'EOF';
  _ 
 (x)
  ~
EOF

$type{"\\ominus"}="record";
$contents{"\\ominus"}="3,5,1,0," . <<'EOF';
  _ 
 (-)
  ~
EOF

$type{"\\odot"}="record";
$contents{"\\odot"}="3,5,1,0," . <<'EOF';
  _ 
 (.)
  ~
EOF

$type{"\\leq"}="record";
$contents{"\\leq"}="2,3,1,0," . <<'EOF';
 _
 <
EOF

$type{"\\equiv"}="record";
$contents{"\\equiv"}="2,3,1,0," . <<'EOF';
 _
 =
EOF

$type{"\\not"}="record";
$contents{"\\not"}="2,4,1,0," . <<'EOF';
 _
  |
EOF

$type{"\\geq"}="record";
$contents{"\\geq"}="2,3,1,0," . <<'EOF';
 _
 >
EOF

$type{"\\partial"}="record";
$contents{"\\partial"}="2,1,1,0," . <<'EOF';
\
d
EOF

$type{"\\forall"}="record";
$contents{"\\forall"}="3,4,1,0," . <<'EOF';
\__/
 \/
EOF

$type{"\\exists"}="record";
$contents{"\\exists"}="3,2,1,0," . <<'EOF';
_.
-|
~'
EOF

$type{"\\owns"}="record";
$contents{"\\owns"}="3,4,1,0," . <<'EOF';
 _
 -)
 ~
EOF

$type{"\\ni"}="record";
$contents{"\\ni"}="3,4,1,0," . <<'EOF';
 _
 -)
 ~
EOF

$type{"\\in"}="record";
$contents{"\\in"}="3,4,1,0," . <<'EOF';
  _
 (-
  ~
EOF

$type{"\\notin"}="record";
$contents{"\\notin"}="3,5,1,0," . <<'EOF';
  |_
 (|-
  |~
EOF

$type{"\\qed"}="record";
$contents{"\\qed"}="2,6,1,0," . <<'EOF';
    _
   |_| 
EOF

$type{"\\Box"}="record";
$contents{"\\Box"}="2,5,1,0," . <<'EOF';
  _
 |_| 
EOF

$type{"\\boxtimes"}="record";
$contents{"\\boxtimes"}="3,5,1,0," . <<'EOF';
  _
 |X| 
  ~
EOF

$type{"\\pm"}="record";
$contents{"\\pm"}="2,1,0,0," . <<'EOF';
+
-
EOF

$type{"\\mp"}="record";
$contents{"\\mp"}="2,1,1,0," . <<'EOF';
_
+
EOF

$type{"\\cong"}="record";
$contents{"\\cong"}="2,1,0,0," . <<'EOF';
=
~
EOF

$type{"\\neq"}="record";
$contents{"\\neq"}="1,5,0,0," . <<'EOF';
 =/= 
EOF

$type{"\\nmid"}="record";
$contents{"\\nmid"}="3,3,1,0," . <<'EOF';
 |/
 |
/|
EOF

$type{"\\subset"}="record";
$contents{"\\subset"}="2,4,1,0," . <<'EOF';
  _ 
 (_ 
EOF

$type{"\\subseteq"}="record";
$contents{"\\subseteq"}="3,4,1,0," . <<'EOF';
  _ 
 (_ 
  ~
EOF

$type{"\\supseteq"}="record";
$contents{"\\subseteq"}="3,4,1,0," . <<'EOF';
 _ 
 _) 
 ~
EOF

$type{"\\supset"}="record";
$contents{"\\supset"}="2,4,1,0," . <<'EOF';
 _
 _)
EOF

$type{"\\sqrt"}="sub1";
$contents{"\\sqrt"}="radical";

$type{"\\buildrel"}="sub3";
$contents{"\\buildrel"}="buildrel";

$type{"\\frac"}="sub2";
$contents{"\\frac"}="fraction";
  
$type{"\\xrightarrow"}="sub2";
$contents{"\\xrightarrow"}="[]right_arrow";
  
$type{"\\xleftarrow"}="sub2";
$contents{"\\xleftarrow"}="[]left_arrow";
  
$type{"\\overset"}="sub2";
$contents{"\\overset"}="overset";

$type{"\\LITERALnoLENGTH"}="sub1";
$contents{"\\LITERALnoLENGTH"}="literal_no_length";

for ("text","operatorname","operatornamewithlimits","relax","-",
     "notag","!","/","protect","mathcal","Bbb","bf","it","em","boldsymbol",
     "cal","Cal","goth","ref","maketitle","expandafter","csname","endcsname",
     "makeatletter","makeatother","topmatter","endtopmatter","rm", "tt",
     "NoBlackBoxes","document","TagsOnRight","bold","dsize","roster",
     "endroster","endkey","endRefs","enddocument","displaystyle",
     "twelverm","tenrm","twelvefm","tenfm","hbox","mbox", "url",
     "tableofcontents", "bigl", "bigr", "biggl", "biggr", "footnotesize",
     "nonumber", "tiny", "sc", "huge", "limits",
    ) {
  $type{"\\$_"}="nothing";
}

if ($opt_ignorefonts) {
  for ("mathbb", "mathit", "mathbit", "mathfrak", "frak", "mathbf",
      ) {
    $type{"\\$_"}="nothing";
  }
}

for ("par","endtitle","endauthor","endaffil","endaddress","endemail","enddate",
     "endhead","key","medskip","smallskip","bigskip","newpage",
     "vfill","eject") {
  $type{"\\$_"}="sub";
  $contents{"\\$_"}="par";
}

for ("proclaim","demo",) {
  $type{"\\$_"}="par_self";
}

for ("endproclaim","enddemo",) {
  $type{"\\$_"}="self_par";
}

$type{"\\today"}="sub";
$contents{"\\today"}="today";

#$type{"&"}="nothing";

$type{"\\let"}="sub";
$contents{"\\let"}="let_exp";

$type{"\\def"}="sub";
$contents{"\\def"}="def_exp";

$type{"\\newcommand"}="sub";
$contents{"\\newcommand"}="def_exp_block";

$type{"\\item"}="sub";
$contents{"\\item"}="item";

$type{"{"}="sub";
$contents{"{"}="open_curly";

$type{"}"}="sub";
$contents{"}"}="close_curly";

$type{"&"}="sub";
$contents{"&"}="ampersand";

$type{'$'}="sub";
$contents{'$'}="dollar";

$type{'$$'}="sub";
$contents{'$$'}="ddollar";

$type{'\\\\'}="sub";
$contents{'\\\\'}="bbackslash";

$type{"^"}="sub1";
$contents{"^"}="superscript";

$type{"_"}="sub1";
$contents{"_"}="subscript";

$type{"@"}="sub";
$contents{"@"}="at";

$type{"\\over"}="sub";
$contents{"\\over"}="over";


$type{"\\choose"}="sub";
$contents{"\\choose"}="choose";

$type{"\\noindent"}="sub";
$contents{"\\noindent"}="noindent";


$type{"\\left"}="sub";
$contents{"\\left"}="left";

$type{"\\right"}="sub";
$contents{"\\right"}="right";

$type{'\footnote'}="sub";
$contents{'\footnote'}="footnote";

$type{"\\underline"}="sub1";
$contents{"\\underline"}="underline";

$type{"\\overline"}="sub1";
$contents{"\\overline"}="overline";

$type{"\\bar"}="sub1";
$contents{"\\bar"}="overline";

$type{"\\v"}="sub1";
$contents{"\\v"}="putover_string;v";

$type{"\\widetilde"}="sub1";
$contents{"\\widetilde"}="widetilde";

$type{"\\underbrace"}="sub2";
$contents{"\\underbrace"}="underbrace2";

$type{"\\overbrace"}="sub2";
$contents{"\\overbrace"}="overbrace2";

$type{"\\~"}="sub1";
$contents{"\\~"}="putover_string;~";

$type{"\\tilde"}="sub1";
$contents{"\\tilde"}="putover_string;~";

$type{"\\widehat"}="sub1";
$contents{"\\widehat"}="widehat";

$type{"\\hat"}="sub1";
$contents{"\\hat"}="putover_string;^";

$type{"\\^"}="sub1";
$contents{"\\^"}="putover_string;^";

$type{'\\"'}="sub1";
$contents{'\\"'}='putover_string;"';

$type{'\\dot'}="sub1";
$contents{'\\dot'}='putover_string;.';

$type{"\\not"}="sub1";
$contents{"\\not"}="not";

$type{"\\label"}="sub1";
$contents{"\\label"}="putpar;(;)";

$type{"\\eqref"}="sub1";
$contents{"\\eqref"}="putpar;(;)";

$type{"\\cite"}="sub1";
$contents{"\\cite"}="putpar;[;]";

$type{"\\begin"}="sub1";
$contents{"\\begin"}="begin";

for ('@',"_","\$","{","}","#","&","arccos","arcsin","arctan","arg","cos",
    "cosh","cot","coth","csc","deg","det","dim","exp","gcd","hom",
    "inf","ker","lg","lim","liminf","limsup","ln","log","max","min",
    "mod","Pr","sec","sin","sinh","sup","tan","tanh", "%") {
  $type{"\\$_"}="self";
}

for ("bibliography","myLabel","theoremstyle","theorembodyfont", "usepackage",
     "bibliographystyle","hphantom","vphantom","phantom","hspace") {
  $type{"\\$_"}="discard1";
}

for ("numberwithin","renewcommand","setcounter"
    ) {
  $type{"\\$_"}="discard2";
}

$type{"\\newenvironment"}="discard3";
$type{"\\DeclareMathAccent"}="discard4";
$type{"\\DeclareMathAlphabet"}="discard5";

#$type{"\\newtheorem"}="sub2";
#$contents{"\\newtheorem"}="newtheorem";

$type{"\\NEWTHEOREMone"}="sub1";
$contents{"\\NEWTHEOREMone"}="newtheorem1";

$type{"\\NEWTHEOREMtwo"}="sub2";
$contents{"\\NEWTHEOREMtwo"}="[]newtheorem2";

for ("equation","gather","align"
     ) {$environment{"$_"}="ddollar,ddollar";} 

for ("matrix","CD","smallmatrix"
     ) {$environment{"$_"}="matrix,endmatrix;1;c";} 

for ("remark", "example", "theorem", "definition", "proof", "abstract",
     "proposition", "amplification", "lemma", "corollary",
     ) {$environment{"$_"}="par:unindent:puts;\U$_\E. ,par";} 

# \thanks inside \author confuse things a lot
for ("title", "author", "affil", "address", "email", "date", # "thanks",
     "section", "subsection", "subsubsection") {
  $type{"\\$_"}="sub";
  $contents{"\\$_"}="par_puts_unindent;\U$_: ";
}

for ("document","split","enumerate"
     ) {$environment_none{"$_"}++;} 

$environment{"Sb"}="subscript:matrix,endmatrix;1;l";

$environment{"Sp"}="superscript:matrix,endmatrix;1;l";

$environment{"eqnarray"}="ddollar:matrix,endmatrix;0;r;c;l:ddollar";
$environment{"eqnarray*"}="ddollar:matrix,endmatrix;0;r;c;l:ddollar";
$environment{"split"}="ddollar:matrix,endmatrix;0;r;l:ddollar";
$environment{"multiline"}="ddollar:matrix,endmatrix;0;r;l:ddollar";
$environment{"align"}="ddollar:matrix,endmatrix;0;r;l:ddollar";
$environment{"aligned"}="matrix,endmatrix;0;r;l";
$environment{"gather"}="ddollar:matrix,endmatrix;0;c:ddollar";
$environment{"gathered"}="matrix,endmatrix;0;c";
$environment{"array"}="arg2stack:matrix,endmatrixArg;1";

# $environment{"pmatrix"}="beg_lr;(;):matrix,endmatrix;1;c";
$environment{"bmatrix"}="beg_lr;[;]:matrix,endmatrix;1;c";
$environment{"vmatrix"}="beg_lr;|;|:matrix,endmatrix;1;c";

$type{"~"}="string";
$contents{"~"}=" ";

$type{"\\,"}="string";
$contents{"\\,"}=" ";

$type{"\\dots"}="string";
$contents{"\\dots"}="...";

$type{"\\and"}="string";
$contents{"\\and"}=" & ";

$type{"\\ldots"}="string";
$contents{"\\ldots"}="...";

$type{"\\cdots"}="string";
$contents{"\\cdots"}="...";

$type{"\\colon"}="string";
$contents{"\\colon"}=": ";

$type{"\\mid"}="string";
$contents{"\\mid"}=" | ";

$type{"\\smallsetminus"}="string";
$contents{"\\smallsetminus"}=" \\ ";

$type{"\\setminus"}="string";
$contents{"\\setminus"}=" \\ ";

$type{"\\backslash"}="string";
$contents{"\\backslash"}="\\";

$type{"\\iff"}="string";
$contents{"\\iff"}=" <==> ";

$type{"\\approx"}="string";
$contents{"\\approx"}=" ~ ";

$type{"\\simeq"}="string";
$contents{"\\simeq"}=" ~ ";

$type{"\\quad"}="string";
$contents{"\\quad"}="   ";

$type{"\\qquad"}="string";
$contents{"\\qquad"}="     ";

$type{"\\to"}="string";
$contents{"\\to"}=" --> ";

$type{"\\from"}="string";
$contents{"\\from"}=" <-- ";

$type{"\\wedge"}="string";
$contents{"\\wedge"}="/\\";

$type{"\\vee"}="string";
$contents{"\\vee"}="\\/";

$type{"\\Lambda"}="string";
$contents{"\\Lambda"}="/\\";

$type{"\\ltimes"}="string";
$contents{"\\ltimes"}=" |>< ";

$type{"\\lhd"}="string";
$contents{"\\lhd"}=" <| ";

$type{"\\rhd"}="string";
$contents{"\\rhd"}=" |> ";

$type{"\\cdot"}="string";
$contents{"\\cdot"}=" . ";

# $type{"\dot"}="string";
# $contents{"\\dot"}=" . ";

$type{"\\circ"}="string";
$contents{"\\circ"}=" o ";

$type{"\\bullet"}="string";
$contents{"\\bullet"}="\@";

$type{"\\infty"}="string";
$contents{"\\infty"}="oo";

$type{"\\rtimes"}="string";
$contents{"\\rtimes"}=" ><| ";

$type{"\\times"}="string";
$contents{"\\times"}=" >< ";

$type{"\\gg"}="string";
$contents{"\\gg"}=" >> ";

$type{"\\ll"}="string";
$contents{"\\ll"}=" << ";

$type{"\\hookrightarrow"}="string";
$contents{"\\hookrightarrow"}=" c--> ";

$type{"\\hookleftarrow"}="string";
$contents{"\\hookleftarrow"}=" <--j ";

$type{"\\longleftarrow"}="string";
$contents{"\\longleftarrow"}=" <----- ";

$type{"\\longleftrightarrow"}="string";
$contents{"\\longleftrightarrow"}=" <----> ";

$type{"\\longrightarrow"}="string";
$contents{"\\longrightarrow"}=" -----> ";

$type{"\\rightarrow"}="string";
$contents{"\\rightarrow"}=" ---> ";

$type{"\\leftarrow"}="string";
$contents{"\\leftarrow"}=" <--- ";

$type{"\\mapsto"}="string";
$contents{"\\mapsto"}=" :--> ";

$type{"\\longmapsto"}="string";
$contents{"\\longmapsto"}=" :----> ";

$type{"\\cap"}="string";
$contents{"\\cap"}=" /~\\ ";

$type{"\\cup"}="string";
$contents{"\\cup"}=" \\_/ ";

$type{"\|"}="string";
$contents{"\|"}="||";

$type{'\;'}="string";
$contents{'\;'}=" ";

$type{'\ '}="string";
$contents{'\ '}=" ";

$type{'\noindent'}="string";
$contents{'\noindent'}="";

$type{'\enspace'}="string";
$contents{'\enspace'}="  ";

$type{"\\thanks"}="string";
$contents{"\\thanks"}=" THANKS: ";

$type{"\\vert"}="string";
$contents{"\\vert"}=" | ";

$type{"\\Vert"}="string";
$contents{"\\Vert"}=" || ";

$type{"\\ast"}="string";
$contents{"\\ast"}=" * ";

$type{"\\prime"}="string";
$contents{"\\prime"}="'";

$type{"\\endgraph"}="string";
$contents{"\\endgraph"}=" \\NEWPAR ";

&define('\\define','\\def');
&define('\\ge','\\geq ');
&define('\\le','\\leq ');
&define('\\ne','\\neq ');
&define('\\langle','<');
&define('\\rangle','>');
&define('\\subheading','\\par\\underline ');
&define('\\(','$');
&define('\\)','$');
&define('\\[','$$');
&define('\\]','$$');
&define('\\centerline#1','$$#1$$');
&define('\\eqalign#1','\\aligned #1 \\endaligned ');
&define('\\eqalignno#1','\\aligned #1 \\endaligned ');
&define('\\cr','\\\\');
&define('\\sb','_');
&define('\\sp','^');
&define('\\iint','\int\int ');
&define('\\iiint','\int\int\int ');
&define('\\proclaim','\\noindent ');
&define('\\mathring','\\overset{\circ}');
&define('\\binom#1#2','{#1\choose{}#2}');
&define('\\bibitem#1','[#1]');
&define('\\newline','\par ');
&define('\\newtheorem#1','\\NEWTHEOREMone{#1}\\NEWTHEOREMtwo ');
&defb("matrix","vmatrix","Vmatrix","smallmatrix","bmatrix","Sp","Sb",
      "CD","align","aligned","split","multiline","gather","gathered");

for ("documentclass", "documentstyle") {
  $type{"\\$_"}="sub2";
  $contents{"\\$_"}="[]discard";
}

# works as \end in LaTeX
$type{"\\endTeXtoMail"}="sub1";
$contents{"\\endTeXtoMail"}="end";

if ($opt_TeX) {
  &define('\pmatrix#1','\left(\begin{matrix}#1\endTeXtoMail{matrix}\right)');
  $type{"\\end"}="sub";
  $contents{"\\end"}="end_TeX";
} else {
  $environment{"pmatrix"}="beg_lr;(;):matrix,endmatrix;1;c";
  &defb("pmatrix") unless $opt_TeX;
  $type{"\\end"}="sub1";
  $contents{"\\end"}="end";
}

  
  ## All the records should be specified before this point
  {local(@a)=grep("record" eq $type{$_},keys %type); 
		for (@a) {chop $contents{$_} if 
      substr($contents{$_},length($contents{$_})-1,1) eq "\n";}}

for ("oplus","otimes","cup","wedge") {
  $type{"\\big$_"}=$type{"\\$_"};
  $contents{"\\big$_"}=$contents{"\\$_"};
}


@level=(0);
@chunks=(0);
@tokenByToken=(0);
@out=();
$curlength=0;
$debug_flow=1;
$debug_record=2;
$debug_parsing=4;
$debug_length=8;
$debug_matrix=16;
#$debug |= $debug_flow | $debug_record | $debug_parsing | $debug_length;
#$debug |= $debug_flow;
#$debug |= $debug_record;
#$debug |= $debug_parsing;
#$debug |= $debug_length;
#$debug |= $debug_matrix;


$/ = $opt_by_par ? "\n\n" : ''; # whole paragraph mode
while (&paragraph()) { 1 }
&finishBuffer;

__END__

# History: Jul 98: \choose added, fixed RE for \noindent, \eqalign and \cr.
#			\proclaim and better \noindent added.
# Sep 98: last was used inside an if block, was leaking out.
# Jan 00: \sb \sp
# Feb 00: remove extraneous second EOF needed at end.
	  remove an empty line at end of output
	  New option -by_par to support per-paragraph processing
	  New option -TeX which support a different \pmatrix
	  New option -ragged to not insert whitespace to align right margin.
	  New option -noindent to not insert whitespace at beginning.
	  Ignore \\ and \cr if followed by \end{whatever}.
	  Ignore \noindent if not important.
	  Ignore whitespace paragraphs.
# Apr 00: Finishing a level 1 would not merge things into one chunk.
# May 00: Additional argument to finish() to distinguish finishing
	  things which cannot be broken between lines.
# Sep 00: Add support for new macro for strings with screen escapes sequences:
	  \LITERALnoLENGTH{escapeseq}.
# Oct 00: \LITERALnoLENGTH can have a chance to work in the baseline only;
	   in fact the previous version did not work even there...
	  If the added record is longer than line length, do not try to
	  break the line before it...
# Apr 03: new option ignorefonts
	  Hanging `}' (e.g., caused by translation of \\ to \par) would break
	    processing of the rest of the file.
	  Could not treat fraction as the first thing on the line (\noindent
	    required).
	  Support many more macros.
	  Better support for \end (with -TeX), \footnote, \endgraph.
	  Allow \over and other infix macros inside \left(\right).
	  \label would not update $curlength.
	  Whitespace edits.
	  Update the limit of expansion of definitions to 10000 per paragraph
	  (a recursion guard - used, e.g., per TeX's \pmatrix).
	  New option scissors to emit a line when a high line is cut into
	    pieces (disabled when "").
	  New option noflush (rarily useful optimization).
	  Flush the output by default.
	  \limits ignored.
	  Allow one-level-deep *{NUMBER}{PRE} in array specifier (in addition
		to c,r,l).
