stable 2004.01.02

4 files changed, 1638 insertions, 1413 deletions

diff --git a/metapost/context/base/mp-core.mp b/metapost/context/base/mp-core.mp
index 72347734f..64ac0dfff 100644
--- a/metapost/context/base/mp-core.mp
+++ b/metapost/context/base/mp-core.mp
@@ -39,10 +39,10 @@ def initialize_box_pos (expr pos,n,x,y,w,h,d) =
   pxy  := llxy--lrxy--urxy--ulxy--cycle ;
   cxy  := center pxy ;
   nxy  := n ;
-  freeze_box(pos) ; 
+  freeze_box(pos) ;
 enddef ;
 
-def freeze_box (expr pos) = 
+def freeze_box (expr pos) =
   lxy[pos]  := lxy  ;
   llxy[pos] := llxy ;
   lrxy[pos] := lrxy ;
@@ -55,7 +55,7 @@ def freeze_box (expr pos) =
   pxy[pos]  := pxy  ;
   cxy[pos]  := cxy  ;
   nxy[pos]  := nxy  ;
-enddef ; 
+enddef ;
 
 def initialize_box (expr n,x,y,w,h,d) =
 
@@ -88,13 +88,13 @@ def do_initialize_area (expr fpos, tpos) =
 enddef ;
 
 def set_par_line_height (expr ph, pd) =
-  par_strut_height := 
-    if ph>0 : ph elseif StrutHeight>0 : StrutHeight else : 8pt fi ; 
+  par_strut_height :=
+    if ph>0 : ph elseif StrutHeight>0 : StrutHeight else : 8pt fi ;
   par_strut_depth  :=
-    if pd>0 : pd elseif StrutDepth >0 : StrutDepth  else : 3pt fi ; 
-  par_line_height  := 
+    if pd>0 : pd elseif StrutDepth >0 : StrutDepth  else : 3pt fi ;
+  par_line_height  :=
     par_strut_height + par_strut_depth ;
-enddef ; 
+enddef ;
 
 def initialize_par (expr fn,fx,fy,fw,fh,fd,
                          tn,tx,ty,tw,th,td,
@@ -109,7 +109,7 @@ def initialize_par (expr fn,fx,fy,fw,fh,fd,
 
   numeric par_strut_height, par_strut_depth, par_line_height ;
 
-  set_par_line_height (ph, pd) ; 
+  set_par_line_height (ph, pd) ;
 
   do_initialize_area (fpos, tpos) ;
   do_initialize_par  (fpos, tpos, mpos, ppos, rw,rl,rr,rh,ra,ri) ;
@@ -126,14 +126,14 @@ def initialize_area_par (expr fn,fx,fy,fw,fh,fd,
 
   numeric par_strut_height, par_strut_depth, par_line_height ;
 
-  set_par_line_height (wh, wd) ; 
+  set_par_line_height (wh, wd) ;
 
   numeric ffpos ; ffpos := 4 ; initialize_box_pos(ffpos,wn,wx,fy,0,wh,wd) ;
   numeric ttpos ; ttpos := 5 ; initialize_box_pos(ttpos,wn,wx+ww,ty,0,wh,wd) ;
 
-  do_initialize_area (ffpos, ttpos) ; 
+  do_initialize_area (ffpos, ttpos) ;
 
-  numeric mpos ; mpos := 6 ; freeze_box(mpos) ; 
+  numeric mpos ; mpos := 6 ; freeze_box(mpos) ;
 
 % do_initialize_area (fpos, tpos) ;
   do_initialize_par  (fpos, tpos, mpos, ffpos, 0,0,0,0,0,0) ;
@@ -142,92 +142,92 @@ enddef ;
 
 def do_initialize_par (expr fpos, tpos, mpos, ppos, rw,rl,rr,rh,ra,ri) =
 
-  pair lref, rref, pref, lhref, rhref ; 
+  pair lref, rref, pref, lhref, rhref ;
 
   % clip the page area to the left and right skips
 
-  llxy[mpos] := llxy[mpos] shifted (+rl,0) ; 
-  lrxy[mpos] := lrxy[mpos] shifted (-rr,0) ; 
-  urxy[mpos] := urxy[mpos] shifted (-rr,0) ; 
-  ulxy[mpos] := ulxy[mpos] shifted (+rl,0) ; 
+  llxy[mpos] := llxy[mpos] shifted (+rl,0) ;
+  lrxy[mpos] := lrxy[mpos] shifted (-rr,0) ;
+  urxy[mpos] := urxy[mpos] shifted (-rr,0) ;
+  ulxy[mpos] := ulxy[mpos] shifted (+rl,0) ;
 
   % fixate the leftskip, rightskip and hanging indentation
-  
-  lref := (xpart llxy[mpos],ypart ulxy[ppos]) ; lhref := lref shifted (rh,0) ; 
-  rref := (xpart lrxy[mpos],ypart urxy[ppos]) ; rhref := rref shifted (rh,0) ; 
-
-  pref := lxy[ppos] ;  
-
-  if nxy[tpos] > nxy[fpos] : 
-    if nxy[fpos] = nxy[mpos] : 
-      % first of multiple pages 
-      llxy[tpos] := llxy[mpos] ; 
-      lrxy[tpos] := lrxy[mpos] ; 
-      urxy[tpos] := lrxy[mpos] shifted (0,par_line_height) ; 
-      ulxy[tpos] := llxy[mpos] shifted (0,par_line_height) ; 
-      boxgriddirection := down ; 
-    elseif nxy[tpos] = nxy[mpos] : 
-      % last of multiple pages 
-      llxy[fpos] := ulxy[mpos] shifted (0,-par_line_height) ; 
-      lrxy[fpos] := urxy[mpos] shifted (0,-par_line_height) ; 
-      urxy[fpos] := urxy[mpos] ; 
-      ulxy[fpos] := ulxy[mpos] ; 
-      boxgriddirection := up ; 
-    else : 
-      % middle of multiple pages 
-      llxy[fpos] := ulxy[mpos] shifted (0,-par_line_height) ; 
-      lrxy[fpos] := urxy[mpos] shifted (0,-par_line_height) ; 
-      urxy[fpos] := urxy[mpos] ; 
-      ulxy[fpos] := ulxy[mpos] ; 
-      llxy[tpos] := llxy[mpos] ; 
-      lrxy[tpos] := lrxy[mpos] ; 
-      urxy[tpos] := lrxy[mpos] shifted (0,par_line_height) ; 
-      ulxy[tpos] := llxy[mpos] shifted (0,par_line_height) ; 
-      boxgriddirection := up ; 
+
+  lref := (xpart llxy[mpos],ypart ulxy[ppos]) ; lhref := lref shifted (rh,0) ;
+  rref := (xpart lrxy[mpos],ypart urxy[ppos]) ; rhref := rref shifted (rh,0) ;
+
+  pref := lxy[ppos] ;
+
+  if nxy[tpos] > nxy[fpos] :
+    if nxy[fpos] = nxy[mpos] :
+      % first of multiple pages
+      llxy[tpos] := llxy[mpos] ;
+      lrxy[tpos] := lrxy[mpos] ;
+      urxy[tpos] := lrxy[mpos] shifted (0,par_line_height) ;
+      ulxy[tpos] := llxy[mpos] shifted (0,par_line_height) ;
+      boxgriddirection := down ;
+    elseif nxy[tpos] = nxy[mpos] :
+      % last of multiple pages
+      llxy[fpos] := ulxy[mpos] shifted (0,-par_line_height) ;
+      lrxy[fpos] := urxy[mpos] shifted (0,-par_line_height) ;
+      urxy[fpos] := urxy[mpos] ;
+      ulxy[fpos] := ulxy[mpos] ;
+      boxgriddirection := up ;
+    else :
+      % middle of multiple pages
+      llxy[fpos] := ulxy[mpos] shifted (0,-par_line_height) ;
+      lrxy[fpos] := urxy[mpos] shifted (0,-par_line_height) ;
+      urxy[fpos] := urxy[mpos] ;
+      ulxy[fpos] := ulxy[mpos] ;
+      llxy[tpos] := llxy[mpos] ;
+      lrxy[tpos] := lrxy[mpos] ;
+      urxy[tpos] := lrxy[mpos] shifted (0,par_line_height) ;
+      ulxy[tpos] := llxy[mpos] shifted (0,par_line_height) ;
+      boxgriddirection := up ;
     fi ;
-  else : 
-    % just one page 
-    boxgriddirection := up ; 
-  fi ; 
+  else :
+    % just one page
+    boxgriddirection := up ;
+  fi ;
 
-  path txy, bxy, pxy, mxy ; 
+  path txy, bxy, pxy, mxy ;
 
-  txy := originpath ; % top 
-  bxy := originpath ; % bottom 
+  txy := originpath ; % top
+  bxy := originpath ; % bottom
   pxy := originpath ; % composed
 
-  boolean lefthang, righthang, somehang ; 
+  boolean lefthang, righthang, somehang ;
 
-  % we only hang on the first of a multiple page background 
+  % we only hang on the first of a multiple page background
 
-  if nxy[mpos] > nxy[fpos] : 
-    lefthang := righthang := somehang := false ; 
-  else : 
-    lefthang := (rh>0) ; righthang := (rh<0) ; somehang := false ; 
-  fi ; 
+  if nxy[mpos] > nxy[fpos] :
+    lefthang := righthang := somehang := false ;
+  else :
+    lefthang := (rh>0) ; righthang := (rh<0) ; somehang := false ;
+  fi ;
 
   if lefthang :
-    mxy  := boundingbox (lref -- lref shifted (rh,ra*par_line_height)) ; 
-  elseif righthang : 
-    mxy  := boundingbox (rref -- rref shifted (rh,ra*par_line_height)) ; 
+    mxy  := boundingbox (lref -- lref shifted (rh,ra*par_line_height)) ;
+  elseif righthang :
+    mxy  := boundingbox (rref -- rref shifted (rh,ra*par_line_height)) ;
   else :
-    mxy  := originpath ;  
+    mxy  := originpath ;
   fi ;
 
-  if round(ypart llxy[fpos]) = round(ypart llxy[tpos]) : 
+  if round(ypart llxy[fpos]) = round(ypart llxy[tpos]) :
 
     % We have a one-liner. Watch how er use the bottom pos for
     % determining the height.
 
-    llxy[fpos] := (xpart llxy[fpos], ypart llxy[tpos]) ; 
-    ulxy[fpos] := (xpart ulxy[fpos], ypart ulxy[tpos]) ; 
+    llxy[fpos] := (xpart llxy[fpos], ypart llxy[tpos]) ;
+    ulxy[fpos] := (xpart ulxy[fpos], ypart ulxy[tpos]) ;
 
-  else : 
+  else :
 
-    % We have a multi-liner. For convenience we now correct the 
-    % begin and end points for indentation.  
+    % We have a multi-liner. For convenience we now correct the
+    % begin and end points for indentation.
 
-    if lefthang and (round(ypart llxy[tpos]) >= round(ypart lrcorner mxy)) : 
+    if lefthang and (round(ypart llxy[tpos]) >= round(ypart lrcorner mxy)) :
       llxy[tpos] := (xpart lhref, ypart llxy[tpos]) ;
       ulxy[tpos] := (xpart lhref, ypart ulxy[tpos]) ;
     else :
@@ -240,26 +240,26 @@ def do_initialize_par (expr fpos, tpos, mpos, ppos, rw,rl,rr,rh,ra,ri) =
       urxy[fpos] := (xpart rhref, ypart urxy[fpos]) ;
     else :
       lrxy[fpos] := (xpart  rref, ypart lrxy[fpos]) ;
-      urxy[fpos] := (xpart  rref, ypart urxy[fpos]) ;  
+      urxy[fpos] := (xpart  rref, ypart urxy[fpos]) ;
     fi ;
 
-  fi ; 
+  fi ;
 
-  somehang := (ypart ulxy[fpos]>ypart llcorner mxy) and 
+  somehang := (ypart ulxy[fpos]>ypart llcorner mxy) and
               (ypart llxy[tpos]<ypart llcorner mxy) ;
 
-  if round(ypart llxy[fpos]) = round(ypart llxy[tpos]) : 
+  if round(ypart llxy[fpos]) = round(ypart llxy[tpos]) :
 
-    % A (short) one-liner goes into the top box. 
+    % A (short) one-liner goes into the top box.
 
     txy := llxy[fpos] -- lrxy[tpos] -- urxy[tpos] -- ulxy[fpos] -- cycle ;
 
   elseif (round(ypart llxy[fpos]) = round(ypart ulxy[tpos])) and
          (round(xpart lrxy[tpos]) < round(xpart llxy[fpos])) :
 
-    % We have a sentence that spans two lines but with only end 
-    % of line and begin of line segments. We need to take care of 
-    % indentation. 
+    % We have a sentence that spans two lines but with only end
+    % of line and begin of line segments. We need to take care of
+    % indentation.
 
     txy := llxy[fpos] -- lrxy[fpos] -- urxy[fpos] -- ulxy[fpos] -- cycle ;
     bxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] -- ulxy[tpos] -- cycle ;
@@ -271,92 +271,92 @@ def do_initialize_par (expr fpos, tpos, mpos, ppos, rw,rl,rr,rh,ra,ri) =
     pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] -- lrxy[fpos] --
            urxy[fpos] -- ulxy[fpos] -- llxy[fpos] -- ulxy[tpos] -- cycle ;
 
-  elseif lefthang and somehang : 
+  elseif lefthang and somehang :
 
-    % We have a sentence that spans more than two lines with 
-    % left hanging indentation. 
+    % We have a sentence that spans more than two lines with
+    % left hanging indentation.
 
-    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] -- 
+    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] --
            (xpart urxy[fpos],ypart urxy[tpos]) --
-           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] -- 
-           if round(ypart urxy[tpos]) < round(ypart llcorner mxy) : 
-             (xpart lrcorner mxy,ypart llxy[fpos]) -- 
-             lrcorner mxy -- 
-             (xpart llxy[tpos],ypart llcorner mxy) -- 
-           else : 
-             (xpart llxy[tpos],ypart llxy[fpos]) -- 
-           fi 
+           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] --
+           if round(ypart urxy[tpos]) < round(ypart llcorner mxy) :
+             (xpart lrcorner mxy,ypart llxy[fpos]) --
+             lrcorner mxy --
+             (xpart llxy[tpos],ypart llcorner mxy) --
+           else :
+             (xpart llxy[tpos],ypart llxy[fpos]) --
+           fi
            cycle ;
 
   elseif righthang and somehang :
 
-    % We have a sentence that spans more than two lines with 
-    % right hanging indentation. 
+    % We have a sentence that spans more than two lines with
+    % right hanging indentation.
 
-    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] -- 
-           if round(ypart urxy[tpos]) < round(ypart llcorner mxy) :  
+    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] --
+           if round(ypart urxy[tpos]) < round(ypart llcorner mxy) :
              (xpart lrcorner mxy,ypart urxy[tpos]) --
              lrcorner mxy -- llcorner mxy --
-           else : 
+           else :
              (xpart urxy[fpos],ypart urxy[tpos]) --
-           fi 
-           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] -- 
-           (xpart llxy[tpos],ypart llxy[fpos]) -- 
+           fi
+           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] --
+           (xpart llxy[tpos],ypart llxy[fpos]) --
            cycle ;
 
-  else :       
+  else :
 
-    % We have a sentence that spans more than two lines with 
-    % no hanging indentation. 
+    % We have a sentence that spans more than two lines with
+    % no hanging indentation.
 
-    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] -- 
+    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] --
            (xpart urxy[fpos],ypart urxy[tpos]) --
-           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] -- 
+           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] --
            (xpart llxy[tpos],ypart llxy[fpos]) -- cycle ;
 
   fi ;
 
-  pxy := simplified pxy ; 
-  pxy := unspiked   pxy ; 
+  pxy := simplified pxy ;
+  pxy := unspiked   pxy ;
 
 enddef ;
 
-TopSkip     := 0 ; % will move 
-StrutHeight := 0 ; % will move 
- 
-pair last_multi_par_shift ; last_multi_par_shift := origin ; 
+TopSkip     := 0 ; % will move
+StrutHeight := 0 ; % will move
+
+pair last_multi_par_shift ; last_multi_par_shift := origin ;
 
-def relocate_multipars (expr xy) = 
-  last_multi_par_shift := xy ; 
-  for i=1 upto nofmultipars : 
+def relocate_multipars (expr xy) =
+  last_multi_par_shift := xy ;
+  for i=1 upto nofmultipars :
     multipars[i] := multipars[i] shifted last_multi_par_shift ;
-  endfor ; 
-enddef ; 
- 
-boolean compensate_multi_par_topskip ; 
-boolean span_multi_column_pars ; 
-boolean auto_multi_par_hsize ; 
+  endfor ;
+enddef ;
+
+boolean compensate_multi_par_topskip ;
+boolean span_multi_column_pars ;
+boolean auto_multi_par_hsize ;
 boolean enable_multi_par_fallback ;
 
-compensate_multi_par_topskip := true ; 
+compensate_multi_par_topskip := true ;
 span_multi_column_pars       := false ;
 auto_multi_par_hsize         := false ; % true ;
 enable_multi_par_fallback    := true ;
 
-vardef multi_par_at_top (expr i) = 
-  (round (ypart ulcorner multipars[i]) = round (ypart ulcorner 
+vardef multi_par_at_top (expr i) =
+  (round (ypart ulcorner multipars[i]) = round (ypart ulcorner
      (TextAreas[multirefs[i]] shifted last_multi_par_shift)))
-enddef ; 
+enddef ;
 
-numeric nofmultipars ; nofmultipars := 0 ; 
+numeric nofmultipars ; nofmultipars := 0 ;
 
 boolean obey_multi_par_hang   ; obey_multi_par_hang   := true ;
 boolean obey_multi_par_more   ; obey_multi_par_more   := true ;
 boolean snap_multi_par_tops   ; snap_multi_par_tops   := true ;
-boolean local_multi_par_area  ; local_multi_par_area  := false ; 
-boolean ignore_multi_par_page ; ignore_multi_par_page := false ; 
+boolean local_multi_par_area  ; local_multi_par_area  := false ;
+boolean ignore_multi_par_page ; ignore_multi_par_page := false ;
 
-boolean one_piece_multi_par   ; one_piece_multi_par   := false ; 
+boolean one_piece_multi_par   ; one_piece_multi_par   := false ;
 
 def simplify_multi_pars = % boundingbox ipv shape als optie
   for i := 1 upto nofmultipars :
@@ -387,30 +387,30 @@ def prepare_multi_pars (expr fn,fx,fy,fw,fh,fd,
     NOfTextAreas := NOfTextColumns ;
   fi ;
 
-  last_multi_par_shift := origin ; 
+  last_multi_par_shift := origin ;
 
   numeric fpos ; fpos := 1 ; initialize_box_pos(fpos,fn,fx,fy,fw,fh,fd) ;
   numeric tpos ; tpos := 2 ; initialize_box_pos(tpos,tn,tx,ty,tw,th,td) ;
   numeric wpos ; wpos := 3 ; initialize_box_pos(wpos,wn,wx,wy,ww,wh,wd) ;
   numeric ppos ; ppos := 4 ; initialize_box_pos(ppos,pn,px,py,pw,ph,pd) ;
 
-  if local_multi_par_area : 
-    RealPageNumber := fn ; 
-    NOfTextAreas := 1 ;  
-    NOfSavedTextAreas := 0 ;  
+  if local_multi_par_area :
+    RealPageNumber := fn ;
+    NOfTextAreas := 1 ;
+    NOfSavedTextAreas := 0 ;
     TextAreas[1] := TextAreas[0] ;
     TextColumns[1] := TextColumns[0] ;
-    nxy[fpos] := nxy[tpos] := nxy[wpos] := nxy[ppos] := RealPageNumber ;  
+    nxy[fpos] := nxy[tpos] := nxy[wpos] := nxy[ppos] := RealPageNumber ;
    % draw TextColumns[1] withcolor green ;
    % draw TextAreas[1] withcolor green ;
   elseif ignore_multi_par_page :
-    RealPageNumber := fn ; 
-    nxy[fpos] := nxy[tpos] := nxy[wpos] := nxy[ppos] := RealPageNumber ;  
-  fi ; 
+    RealPageNumber := fn ;
+    nxy[fpos] := nxy[tpos] := nxy[wpos] := nxy[ppos] := RealPageNumber ;
+  fi ;
 
   numeric par_strut_height, par_strut_depth, par_line_height ;
 
-  set_par_line_height (ph, pd) ; 
+  set_par_line_height (ph, pd) ;
 
   numeric par_hang_indent, par_hang_after, par_indent, par_left_skip ;
 
@@ -423,8 +423,8 @@ def prepare_multi_pars (expr fn,fx,fy,fw,fh,fd,
 
 % par_start_pos := llxy[fpos] if par_indent<0: shifted (-par_indent,0) fi ;
 
-  par_start_pos := llxy[fpos] 
-    if par_indent   <0: shifted (-par_indent,   0) fi 
+  par_start_pos := llxy[fpos]
+    if par_indent   <0: shifted (-par_indent,   0) fi
     if par_left_skip<0: shifted (-par_left_skip,0) fi ;
 
   if wxy[wpos]>0 :
@@ -439,28 +439,28 @@ def prepare_multi_pars (expr fn,fx,fy,fw,fh,fd,
   numeric multiref, multirefs[] ;
   numeric multiloc, multilocs[] ; % 1=begin 2=between 3=end
 
-  numeric multi_par_pages ; multi_par_pages := nxy[tpos]-nxy[fpos]+1 ; 
+  numeric multi_par_pages ; multi_par_pages := nxy[tpos]-nxy[fpos]+1 ;
 
   ii := 0 ; nn := NOfTextAreas+1 ; nofmultipars := 0 ;
 
   vardef snapped_multi_pos (expr p) =
     if snap_multi_par_tops :
       if abs(ypart p - ypart ulcorner multipar) < par_line_height :
-        (xpart p,ypart ulcorner multipar)  
-      else : 
-        p 
-      fi 
+        (xpart p,ypart ulcorner multipar)
+      else :
+        p
+      fi
     else :
-      p 
-    fi 
-  enddef ; 
+      p
+    fi
+  enddef ;
 
   % def set_multipar (expr i) =
   %   ((TextAreas[i] leftenlarged -left_skip) rightenlarged -right_skip)
   % enddef ;
 
   vardef set_multipar (expr i) =
-    ( (TextAreas[i] leftenlarged -left_skip) rightenlarged (-right_skip 
+    ( (TextAreas[i] leftenlarged -left_skip) rightenlarged (-right_skip
       if auto_multi_par_hsize : + rw - bbwidth(TextAreas[i]) fi) )
   enddef ;
 
@@ -518,7 +518,7 @@ def prepare_multi_pars (expr fn,fx,fy,fw,fh,fd,
 par_hang_after := ra + estimated_par_lines(py-fy) ;
 
     if (par_hang_indent>0) and (par_hang_after<0) and obey_multi_par_hang :
-      pair _ul_ ; _ul_ := (xpart ulcorner multipar, ypart snapped_multi_pos(ulxy[fpos]));  
+      pair _ul_ ; _ul_ := (xpart ulcorner multipar, ypart snapped_multi_pos(ulxy[fpos]));
       pair _pa_ ; _pa_ := _ul_ shifted (0,par_hang_after*par_line_height) ;
       _pa_ := (xpart _pa_,max(ypart _pa_,ypart llcorner multipar)) ;
       if same_area :
@@ -660,11 +660,7 @@ fi ;
 
   vardef x_left_bottom_hang (expr i, t) =
     pair _ll_, _sa_, _pa_ ;
-if t :
-    _sa_ := llxy[tpos] ;
-else :
-  _sa_ := llcorner multipar ;
-fi ;
+    _sa_ := if t : llxy[tpos] else : llcorner multipar fi ;
     if (par_hang_indent>0) and (ra>0) :
       par_hang_after := max(0,ra - estimated_multi_par_height(i,t)) ;
       _ll_ := ulcorner multipar ;
@@ -684,11 +680,7 @@ fi ;
 
   vardef x_right_bottom_hang (expr i, t) =
     pair _lr_, _sa_, _pa_ ;
-if t :
-    _sa_ := snapped_multi_pos(ulxy[tpos]) ;
-else :
-  _sa_ := llcorner multipar ;
-fi ;
+    _sa_ := if t : snapped_multi_pos(ulxy[tpos]) else : llcorner multipar fi ;
     if (par_hang_indent<0) and (ra>0) :
       par_hang_after := max(0,ra - estimated_multi_par_height(i, t)) ;
       _lr_ := urcorner multipar ;
@@ -707,36 +699,37 @@ fi ;
   enddef ;
 
   def test_multipar =
-    multipar :=
-      llcorner multipar --
-      urcorner multipar --
-      lrcorner multipar --
-      ulcorner multipar --
-      cycle ;
+%     multipar :=
+%       llcorner multipar --
+%       urcorner multipar --
+%       lrcorner multipar --
+%       ulcorner multipar --
+%       cycle ;
+    multipar := boundingbox multipar ;
   enddef ;
 
-  % first loop 
+  % first loop
+
+  if enable_multi_par_fallback  and
+     (nxy[fpos]=RealPageNumber) and
+     (nxy[tpos]=RealPageNumber) and not
+     (InsideSomeTextArea(lxy[fpos]) and
+      InsideSomeTextArea(rxy[tpos])) :
 
-  if enable_multi_par_fallback  and 
-     (nxy[fpos]=RealPageNumber) and 
-     (nxy[tpos]=RealPageNumber) and not 
-     (InsideSomeTextArea(lxy[fpos]) and 
-      InsideSomeTextArea(rxy[tpos])) : 
+  % fallback
 
-  % fallback 
+     multipar :=
 
-     multipar := 
- 
-      llxy[fpos] -- 
-      lrxy[tpos] -- 
-      urxy[tpos] -- 
+      llxy[fpos] --
+      lrxy[tpos] --
+      urxy[tpos] --
       ulxy[fpos] -- cycle ;
- 
+
       save_multipar (1,1,multipar) ;
 
   else :
 
-  % normal 
+  % normal
 
   for i=1 upto NOfTextAreas :
 
@@ -779,23 +772,23 @@ fi ;
             llxy[fpos] --
             lrxy[tpos] --
            %urxy[tpos] --
-            snapped_multi_pos(urxy[tpos]) --  
+            snapped_multi_pos(urxy[tpos]) --
            %ulxy[fpos] --
-            snapped_multi_pos(ulxy[fpos]) --  
+            snapped_multi_pos(ulxy[fpos]) --
             cycle ;
 
           save_multipar (i,1,multipar) ;
 
-        elseif (ypart llxy[fpos] = ypart ulxy[tpos]) and 
+        elseif (ypart llxy[fpos] = ypart ulxy[tpos]) and
                (xpart llxy[tpos] < xpart llxy[fpos]) :
 
-          % two loners 
+          % two loners
 
           multipar := if obey_multi_par_hang :
 
             right_bottom_hang(true) --
             right_top_hang(true) --
-            snapped_multi_pos(urxy[fpos]) -- 
+            snapped_multi_pos(urxy[fpos]) --
             lrxy[fpos] --
 
           else :
@@ -803,7 +796,7 @@ fi ;
             llxy[fpos] --
             (xpart urcorner multipar, ypart llxy[fpos]) --
             (xpart urcorner multipar, ypart ulxy[fpos]) --
-            snapped_multi_pos(ulxy[fpos]) -- 
+            snapped_multi_pos(ulxy[fpos]) --
 
           fi cycle ;
 
@@ -815,14 +808,14 @@ fi ;
 
             left_bottom_hang(true) --
             llxy[tpos] --
-            snapped_multi_pos(ulxy[tpos]) -- 
+            snapped_multi_pos(ulxy[tpos]) --
             left_top_hang(true) --
 
           else :
 
             (xpart llcorner multipar, ypart llxy[tpos]) --
             llxy[tpos] --
-            snapped_multi_pos(ulxy[tpos]) -- 
+            snapped_multi_pos(ulxy[tpos]) --
             (xpart llcorner multipar, ypart ulxy[tpos]) --
 
           fi cycle ;
@@ -836,11 +829,11 @@ fi ;
             left_bottom_hang(true) --
             llxy[tpos] --
            %ulxy[tpos] --
-            snapped_multi_pos(ulxy[tpos]) -- 
+            snapped_multi_pos(ulxy[tpos]) --
             right_bottom_hang(true) --
             right_top_hang(true) --
            %urxy[fpos] --
-            snapped_multi_pos(urxy[fpos]) -- 
+            snapped_multi_pos(urxy[fpos]) --
             lrxy[fpos] --
             left_top_hang(true) --
 
@@ -848,19 +841,19 @@ fi ;
 
             (xpart llcorner multipar, ypart llxy[tpos]) --
             llxy[tpos] --
-           %ulxy[tpos] -- 
-            snapped_multi_pos(ulxy[tpos]) -- 
+           %ulxy[tpos] --
+            snapped_multi_pos(ulxy[tpos]) --
             (xpart lrcorner multipar, ypart ulxy[tpos]) --
             (xpart urcorner multipar, ypart urxy[fpos]) --
            %urxy[fpos] --
-            snapped_multi_pos(urxy[fpos]) -- 
+            snapped_multi_pos(urxy[fpos]) --
             lrxy[fpos] --
             (xpart ulcorner multipar, ypart lrxy[fpos]) --
 
           fi cycle ;
 
           save_multipar (i,1,multipar) ;
- 
+
         fi ;
 
       else :
@@ -871,7 +864,7 @@ fi ;
           right_bottom_hang(false) --
           right_top_hang(false) --
          %urxy[fpos] --
-          snapped_multi_pos(urxy[fpos]) -- 
+          snapped_multi_pos(urxy[fpos]) --
           lrxy[fpos] --
           left_top_hang(false) --
 
@@ -881,7 +874,7 @@ fi ;
           lrcorner multipar --
           (xpart urcorner multipar, ypart urxy[fpos]) --
          %urxy[fpos] --
-          snapped_multi_pos(urxy[fpos]) -- 
+          snapped_multi_pos(urxy[fpos]) --
           lrxy[fpos] --
           (xpart ulcorner multipar, ypart lrxy[fpos]) --
 
@@ -904,7 +897,7 @@ fi ;
           x_right_top_hang(i,true) --
           x_right_bottom_hang(i,true) --
 %          ulxy[tpos] --
-snapped_multi_pos(ulxy[tpos]) -- 
+snapped_multi_pos(ulxy[tpos]) --
           llxy[tpos] --
           x_left_bottom_hang(i,true) --
           cycle ;
@@ -916,7 +909,7 @@ snapped_multi_pos(ulxy[tpos]) --
           urcorner multipar --
           (xpart lrcorner multipar, ypart urxy[tpos]) --
 %          ulxy[tpos] --
-snapped_multi_pos(ulxy[tpos]) -- 
+snapped_multi_pos(ulxy[tpos]) --
           llxy[tpos] --
           (xpart llcorner multipar, ypart llxy[tpos]) --
           cycle ;
@@ -925,15 +918,15 @@ snapped_multi_pos(ulxy[tpos]) --
 
       save_multipar (i,3,multipar) ;
 
-    else : 
+    else :
+
+      % handled later
 
-      % handled later  
-     
     fi ;
 
   endfor ;
 
-  % second loop 
+  % second loop
 
   for i=ii+1 upto nn-1 :
 
@@ -956,19 +949,19 @@ snapped_multi_pos(ulxy[tpos]) --
 
     save_multipar(i,2,multipar) ;
 
-%fi ; 
+%fi ;
 
   endfor ;
 
-  % end of normal/fallback 
+  % end of normal/fallback
 
-fi ; 
+fi ;
 
   if span_multi_column_pars :
     endgroup ;
   fi ;
 
-  % quick hack for gb: 
+  % quick hack for gb:
 
   one_piece_multi_par := (nofmultipars=1) and (pn=tn) ;
 
@@ -983,8 +976,8 @@ numeric boxfilltype      ; boxfilltype      := 1 ;
 pair    boxgriddirection ; boxgriddirection := up ;
 numeric boxgridwidth     ; boxgridwidth     := 1pt ;
 numeric boxlinewidth     ; boxlinewidth     := 1pt ;
-numeric boxlineradius    ; boxlineradius    := 0pt ; 
-numeric boxfilloffset    ; boxfilloffset    := 0pt ; 
+numeric boxlineradius    ; boxlineradius    := 0pt ;
+numeric boxfilloffset    ; boxfilloffset    := 0pt ;
 numeric boxgriddistance  ; boxgriddistance  := .5cm ;
 
 def draw_box =
@@ -992,19 +985,19 @@ def draw_box =
   draw lxy -- rxy withcolor boxlinecolor withpen pencircle scaled boxgridwidth ;
 enddef ;
 
-def draw_par  = % 1 2 3 11 12 
+def draw_par  = % 1 2 3 11 12
   do_draw_par(pxy) ; do_draw_par(txy) ; do_draw_par(bxy) ;
   for i = pxy, txy, bxy :
         if boxgridtype= 1 :
-      boxgriddirection := origin ; 
+      boxgriddirection := origin ;
       draw baseline_grid (i,boxgriddirection,true ) withcolor boxgridcolor ;
     elseif boxgridtype= 2 :
-      boxgriddirection := origin ; 
+      boxgriddirection := origin ;
       draw baseline_grid (i,boxgriddirection,false) withcolor boxgridcolor ;
     elseif boxgridtype= 3 :
-      boxgriddirection := origin ; 
+      boxgriddirection := origin ;
       draw baseline_grid (i,boxgriddirection,true ) withcolor boxgridcolor ;
-      draw baseline_grid (i,boxgriddirection,true ) 
+      draw baseline_grid (i,boxgriddirection,true )
         shifted (0,ExHeight) withcolor boxgridcolor ;
     elseif boxgridtype=11 :
       draw graphic_grid(i,boxgriddistance,boxgriddistance,boxgriddistance/2,boxgriddistance/2) ;
@@ -1016,50 +1009,50 @@ enddef ;
 
 def do_show_par (expr p, r, c) =
   if length(p) > 2 : for i=0 upto length(p) :
-    draw fullcircle scaled r shifted point i of p 
+    draw fullcircle scaled r shifted point i of p
       withpen pencircle scaled .5pt withcolor c ;
   endfor ; fi ;
   draw p withpen pencircle scaled .5pt withcolor c ;
-enddef ; 
+enddef ;
 
 def show_par  =
-  if length(mxy) > 2 : 
-    draw mxy dashed evenly 
-      withpen pencircle scaled .5pt withcolor .5white ; 
-  fi ;   
+  if length(mxy) > 2 :
+    draw mxy dashed evenly
+      withpen pencircle scaled .5pt withcolor .5white ;
+  fi ;
   do_show_par(txy, 4pt, .5green) ;
   do_show_par(bxy, 6pt, .5blue ) ;
   do_show_par(pxy, 8pt, .5red  ) ;
-  draw pref withpen pencircle scaled 2pt ; 
+  draw pref withpen pencircle scaled 2pt ;
 enddef ;
 
-def sort_multi_pars = 
+def sort_multi_pars =
   if nofmultipars>1 :
-    begingroup ; save _p_, _n_ ; path _p_ ; numeric _n_ ; 
-      for i := 1 upto nofmultipars : 
-        if multilocs[i] = 3 :  
+    begingroup ; save _p_, _n_ ; path _p_ ; numeric _n_ ;
+      for i := 1 upto nofmultipars :
+        if multilocs[i] = 3 :
           _p_ := multipars[nofmultipars] ;
-          multipars[nofmultipars] := multipars[i] ;  
-          multipars[i] := _p_ ; 
+          multipars[nofmultipars] := multipars[i] ;
+          multipars[i] := _p_ ;
           _n_ := multirefs[nofmultipars] ;
-          multirefs[nofmultipars] := multirefs[i] ;  
-          multirefs[i] := _n_ ; 
+          multirefs[nofmultipars] := multirefs[i] ;
+          multirefs[i] := _n_ ;
           _n_ := multilocs[nofmultipars] ;
-          multilocs[nofmultipars] := multilocs[i] ;  
-          multilocs[i] := _n_ ; 
-        fi ;  
+          multilocs[nofmultipars] := multilocs[i] ;
+          multilocs[i] := _n_ ;
+        fi ;
       endfor ;
-    endgroup ; 
-  fi ; 
-enddef ; 
+    endgroup ;
+  fi ;
+enddef ;
 
-% This collapses successive areas (possibly interrupted by 
-% floats. First we need to sort the areas, since they are 
-% normally in de order start, end, inbetween. 
+% This collapses successive areas (possibly interrupted by
+% floats. First we need to sort the areas, since they are
+% normally in de order start, end, inbetween.
 
-def collapse_multi_pars = 
+def collapse_multi_pars =
   if nofmultipars>1 :
-    begingroup ; save _nofmultipars_ ; numeric _nofmultipars_ ; 
+    begingroup ; save _nofmultipars_ ; numeric _nofmultipars_ ;
     _nofmultipars_ := 1 ;
     sort_multi_pars ; % block not in order: 1, 3, 2....
     for i:=1 upto nofmultipars-1 :
@@ -1068,9 +1061,9 @@ def collapse_multi_pars =
 multilocs[_nofmultipars_] := multilocs[i+1] ;
 multirefs[_nofmultipars_] := multirefs[i+1] ;
         multipars[_nofmultipars_] :=
-          ulcorner multipars[_nofmultipars_] -- 
-          urcorner multipars[_nofmultipars_] -- 
-          lrcorner multipars[i+1] -- 
+          ulcorner multipars[_nofmultipars_] --
+          urcorner multipars[_nofmultipars_] --
+          lrcorner multipars[i+1] --
           llcorner multipars[i+1] -- cycle ;
       else :
         _nofmultipars_ := _nofmultipars_ + 1 ;
@@ -1080,83 +1073,83 @@ multirefs[_nofmultipars_] := multirefs[i+1] ;
       fi  ;
     endfor ;
     nofmultipars := _nofmultipars_ ;
-    endgroup ; 
-  fi ; 
+    endgroup ;
+  fi ;
 enddef ;
 
-def draw_multi_pars  = 
-  for i=1 upto nofmultipars : 
-    do_draw_par(multipars[i]) ; 
+def draw_multi_pars  =
+  for i=1 upto nofmultipars :
+    do_draw_par(multipars[i]) ;
         if boxgridtype= 1 :
       draw baseline_grid (multipars[i],up,true ) withcolor boxgridcolor ;
     elseif boxgridtype= 2 :
       draw baseline_grid (multipars[i],up,false) withcolor boxgridcolor ;
     elseif boxgridtype= 3 :
       draw baseline_grid (multipars[i],up,true ) withcolor boxgridcolor ;
-      draw baseline_grid (multipars[i],up,true ) 
+      draw baseline_grid (multipars[i],up,true )
         shifted (0,ExHeight) withcolor boxgridcolor ;
     elseif boxgridtype=11 :
       draw graphic_grid(multipars[i],boxgriddistance,boxgriddistance,boxgriddistance/2,boxgriddistance/2) ;
     elseif boxgridtype=12 :
       draw graphic_grid(multipars[i],boxgriddistance,boxgriddistance,0,0) ;
     fi ;
-  endfor ; 
-enddef ; 
+  endfor ;
+enddef ;
 
-def show_multi_pars  = 
-  for i=1 upto nofmultipars : 
+def show_multi_pars  =
+  for i=1 upto nofmultipars :
     do_show_par(multipars[i], 6pt, .5blue) ;
-  endfor ; 
-enddef ; 
+  endfor ;
+enddef ;
 
 vardef do_draw_par (expr p) =
   if (length p>2) and (bbwidth(p)>1) and (bbheight(p)>1) :
-    save pp ; path pp ; 
-    if (boxlineradius>0) and (boxlinetype=2) : 
-      pp := p cornered boxlineradius ; 
-    else : 
-      pp := p ; 
-    fi ; 
+    save pp ; path pp ;
+    if (boxlineradius>0) and (boxlinetype=2) :
+      pp := p cornered boxlineradius ;
+    else :
+      pp := p ;
+    fi ;
     if boxfilltype>0 :
 if boxfilloffset>0 :
   % temporary hack
-  begingroup ; interim linejoin := mitered ;  
+  begingroup ; interim linejoin := mitered ;
   filldraw pp withcolor boxfillcolor withpen pencircle scaled (2*boxfilloffset) ;
-  endgroup ; 
-else : 
-      fill pp withcolor boxfillcolor ; 
-fi ; 
+  endgroup ;
+else :
+      fill pp withcolor boxfillcolor ;
+fi ;
     fi ;
     if boxlinetype>0 :
-      draw pp withcolor boxlinecolor withpen pencircle scaled boxlinewidth ; 
-    fi ; 
+      draw pp withcolor boxlinecolor withpen pencircle scaled boxlinewidth ;
+    fi ;
   fi ;
 enddef ;
 
 vardef baseline_grid (expr pxy, pdir, at_baseline) =
   if (par_line_height>0) and (bbheight(pxy)>1) and (bbwidth(pxy)>1) and (boxgridwidth>0) :
     save i, grid ; picture grid ; pair start ;
-    def _do_ (expr start) = 
-      draw start -- start shifted (bbwidth(pxy),0) 
-        withpen pencircle scaled boxgridwidth 
+    def _do_ (expr start) =
+      draw start -- start shifted (bbwidth(pxy),0)
+        withpen pencircle scaled boxgridwidth
         withcolor boxgridcolor ;
-    enddef ;  
+    enddef ;
     grid := image
       ( %fails with inlinespace
         %
         if pdir=up :
           for i = if at_baseline : par_strut_depth else : 0 fi
-                  step  par_line_height 
+                  step  par_line_height
                   until max(bbheight(pxy),par_line_height) :
             _do_ (llcorner pxy shifted (0,+i)) ;
           endfor ;
         else :
           for i = if at_baseline : par_strut_height else : 0 fi
-                  step  par_line_height 
+                  step  par_line_height
                   until bbheight(pxy) :
             _do_ (ulcorner pxy shifted (0,-i)) ;
           endfor ;
-        fi ; 
+        fi ;
       ) ;
     clip grid to pxy ;
     grid
@@ -1170,12 +1163,12 @@ vardef graphic_grid (expr pxy, dx, dy, x, y) =
     save grid ; picture grid ;
     grid := image
       ( for i = xpart llcorner pxy step dx until xpart lrcorner pxy :
-          draw (i,ypart llcorner pxy) -- (i,ypart ulcorner pxy) 
-            withpen pencircle scaled boxgridwidth ; 
+          draw (i,ypart llcorner pxy) -- (i,ypart ulcorner pxy)
+            withpen pencircle scaled boxgridwidth ;
         endfor ;
         for i = ypart llcorner pxy step dy until ypart ulcorner pxy :
-          draw (xpart llcorner pxy,i) -- (xpart lrcorner pxy,i) 
-            withpen pencircle scaled boxgridwidth ; 
+          draw (xpart llcorner pxy,i) -- (xpart lrcorner pxy,i)
+            withpen pencircle scaled boxgridwidth ;
         endfor ) shifted (x,y) ;
     clip grid to pxy ;
     grid
@@ -1192,4 +1185,165 @@ let draw_area   = draw_box ;
 let anchor_area = anchor_box ;
 let anchor_par  = anchor_box ;
 
-endinput ;
+% new and experimental and yet undocumented
+
+numeric sync_n[], sync_p[][], sync_w[][], sync_h[][], sync_d[][], sync_t[][] ;
+pair sync_xy[][] ; color sync_c[][] ;
+
+def ResetSyncTasks =
+  path SyncPaths[] ; numeric SyncTasks[], NOfSyncPaths, CurrentSyncClass ;
+  NOfSyncPaths := CurrentSyncClass := 0 ;
+  if unknown SyncLeftOffset : numeric SyncLeftOffset ; SyncLeftOffset := 0          ; fi ;
+  if unknown SyncWidth      : numeric SyncWidth      ; SyncWidth      := 0          ; fi ;
+  if unknown SyncThreshold  : numeric SyncThreshold  ; SyncThreshold  := LineHeight ; fi ;
+  if unknown SyncColor      : color   SyncColor      ; SyncColor      := .5white    ; fi ;
+  if (SyncLeftOffset = 0) and (SyncWidth = 0) :
+    SyncWidth := if known TextWidth : TextWidth else : -1cm fi ;
+  fi ;
+enddef ;
+
+ResetSyncTasks ;
+
+vardef SyncBox(expr n, i, leftoffset, width, topoffset, bottomoffset) =
+   save o ; pair o ; o := (xpart llcorner PlainTextArea,ypart sync_xy[n][i]) ;
+   o shifted (leftoffset,sync_h[n][i]+topoffset) --
+   o shifted (width+leftoffset,sync_h[n][i]+topoffset) --
+   o shifted (width+leftoffset,bottomoffset) --
+   o shifted (leftoffset,bottomoffset) -- cycle
+enddef ;
+
+def SetSyncColor(expr n, i, c) =
+  sync_c[n][i] := c ;
+enddef ;
+
+def SetSyncThreshold(expr n, i, th) =
+  sync_th[n][i] := th ;
+enddef ;
+
+vardef TheSyncColor(expr n, i) =
+  if known sync_c[n][i] : sync_c[n][i] else : SyncColor fi
+enddef ;
+
+vardef TheSyncThreshold(expr n, i) =
+  if known sync_th[n][i] : sync_th[n][i] else : SyncThreshold fi
+enddef ;
+
+vardef PrepareSyncTasks(expr n, collapse, extendtop, prestartnext) =
+  ResetSyncTasks ;
+  if known sync_n[n] :
+    CurrentSyncClass := n ;
+    save ok, l, d ; boolean ok ; ok := false ; NOfSyncPaths := l := 0 ;
+    for i=1 upto sync_n[n] :
+      if RealPageNumber > sync_p[n][i] :
+        l := i ;
+      elseif RealPageNumber = sync_p[n][i] :
+        NOfSyncPaths := NOfSyncPaths + 1 ;
+        if not ok :
+          if i>1 :
+            if sync_t[n][i-1] = sync_t[n][i] :
+              SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, PaperHeight, -PaperHeight) ;
+              SyncTasks[NOfSyncPaths] := i ;
+            else :
+              SyncPaths[NOfSyncPaths] := SyncBox(n, i-1, SyncLeftOffset, SyncWidth, PaperHeight, -PaperHeight) ;
+              SyncTasks[NOfSyncPaths] := i-1 ;
+              NOfSyncPaths := NOfSyncPaths + 1 ;
+              SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, 0, -PaperHeight) ;
+              SyncTasks[NOfSyncPaths] := i ;
+            fi ;
+          else :
+            SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, 0, -PaperHeight) ;
+            SyncTasks[NOfSyncPaths] := i ;
+          fi ;
+        else :
+          SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, 0, -PaperHeight) ;
+          SyncTasks[NOfSyncPaths] := i ;
+        fi ;
+        ok := true ;
+      fi ;
+    endfor ;
+    if (NOfSyncPaths = 0) and (l > 0) :
+      NOfSyncPaths := 1 ;
+      SyncPaths[NOfSyncPaths] := SyncBox(n, l, SyncLeftOffset, SyncWidth, PaperHeight, -PaperHeight) ;
+      SyncTasks[NOfSyncPaths] := l ;
+    fi ;
+    if NOfSyncPaths > 0 :
+      for i = 1 upto NOfSyncPaths-1 :
+        SyncPaths[i] := topboundary SyncPaths[i] -- reverse topboundary SyncPaths[i+1] -- cycle ;
+      endfor ;
+      if unknown SyncThresholdMethod :
+        numeric SyncThresholdMethod ; SyncThresholdMethod := 2 ;
+      fi ;
+      if extendtop :
+        if SyncThresholdMethod = 1 :
+          if NOfSyncPaths>1 :
+            d := ypart (ulcorner PlainTextArea - sync_xy[n][SyncTasks[2]]) ;
+            if (SyncTasks[2]>1) and (d > 0pt) and (d <= TheSyncThreshold(n,sync_t[n][SyncTasks[2]])) and (sync_p[n][SyncTasks[2]] = RealPageNumber) :
+              SyncPaths[2] := SyncPaths[2] topenlarged PaperHeight ;
+            fi ;
+          fi ;
+        else :
+          for i = 1 upto NOfSyncPaths :
+            d := ypart (ulcorner PlainTextArea - sync_xy[n][SyncTasks[i]]) ;
+            if (d > 0) and (d <= TheSyncThreshold(n,sync_t[n][SyncTasks[i]])) and (sync_p[n][SyncTasks[i]] = RealPageNumber) :
+              SyncPaths[i] := SyncPaths[i] topenlarged PaperHeight ;
+            fi ;
+          endfor ;
+        fi ;
+      fi ;
+      if prestartnext :
+        if NOfSyncPaths>1 :
+          if SyncTasks[NOfSyncPaths] < sync_n[n] : % there is a next one
+            d := ypart (ulcorner PlainTextArea - sync_xy[n][SyncTasks[NOfSyncPaths]+1]) ;
+            if (d > 0) and (d <= TheSyncThreshold(n, sync_t[n][SyncTasks[i]])) and (sync_p[n][SyncTasks[NOfSyncPaths]+1] = RealPageNumber+1) :
+              SyncPaths[NOfSyncPaths+1] :=
+                (xpart ulcorner SyncPaths[NOfSyncPaths],ypart llcorner PlainTextArea) --
+                (xpart urcorner SyncPaths[NOfSyncPaths],ypart llcorner PlainTextArea) --
+                lrcorner SyncPaths[NOfSyncPaths] --
+                llcorner SyncPaths[NOfSyncPaths] -- cycle ;
+              SyncTasks[NOfSyncPaths+1] := SyncTasks[NOfSyncPaths]+1 ;
+              NOfSyncPaths := NOfSyncPaths + 1 ;
+            fi ;
+          fi ;
+        fi ;
+      else :
+        if NOfSyncPaths>1 :
+          d := ypart (sync_xy[n][SyncTasks[NOfSyncPaths]] - llcorner PlainTextArea) ;
+          if (d < TheSyncThreshold(n, SyncTasks[NOfSyncPaths])) :
+            NOfSyncPaths := NOfSyncPaths - 1 ;
+            SyncPaths[NOfSyncPaths] := SyncPaths[NOfSyncPaths] bottomenlarged PaperHeight ;
+          fi ;
+        fi ;
+      fi ;
+      if (NOfSyncPaths>1) and collapse :
+        save j ; numeric j ; j := 1 ;
+        for i = 2 upto NOfSyncPaths :
+          if sync_t[n][SyncTasks[i]] = sync_t[n][SyncTasks[j]] :
+            SyncPaths[j] := boundingbox image (draw SyncPaths[i] ; draw SyncPaths[j] ; ) ;
+            SyncTasks[j] := SyncTasks[i] ;
+          else :
+            j := j + 1 ;
+            SyncPaths[j] := SyncPaths[i] ;
+            SyncTasks[j] := SyncTasks[i] ;
+          fi ;
+        endfor ;
+        NOfSyncPaths := j ;
+      fi ;
+    fi ;
+  fi ;
+enddef ;
+
+def SyncTask(expr n) =
+  if known SyncTasks[n] : SyncTasks[n] else : 0 fi
+enddef ;
+
+def FlushSyncTasks =
+  for i = 1 upto NOfSyncPaths :
+    ProcessSyncTask(SyncPaths[i], TheSyncColor(CurrentSyncClass,sync_t[CurrentSyncClass][SyncTasks[i]])) ;
+  endfor ;
+enddef ;
+
+def ProcessSyncTask(expr p, c) =
+  fill p withcolor c ;
+enddef ;
+
+endinput ;
\ No newline at end of file
diff --git a/metapost/context/base/mp-page.mp b/metapost/context/base/mp-page.mp
index af63b921b..e3750b55b 100644
--- a/metapost/context/base/mp-page.mp
+++ b/metapost/context/base/mp-page.mp
@@ -8,20 +8,20 @@
 %D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
 %C
 %C This module is part of the \CONTEXT\ macro||package and is
-%C therefore copyrighted by \PRAGMA. See mreadme.pdf for 
-%C details. 
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
 
-%D This module is rather preliminary and subjected to 
-%D changes. 
+%D This module is rather preliminary and subjected to
+%D changes.
 
-if unknown context_tool : input mp-tool ; fi ; 
-if   known context_page : endinput      ; fi ; 
+if unknown context_tool : input mp-tool ; fi ;
+if   known context_page : endinput      ; fi ;
 
-boolean context_page ; context_page := true ; 
+boolean context_page ; context_page := true ;
 
-if unknown PageStateAvailable : 
-  boolean PageStateAvailable ; PageStateAvailable := false ; 
-fi ; 
+if unknown PageStateAvailable :
+  boolean PageStateAvailable ; PageStateAvailable := false ;
+fi ;
 
 if unknown OnRightPage :
   boolean OnRightPage ; OnRightPage := true ;
@@ -36,10 +36,10 @@ if unknown InPageBody :
 fi ;
 
 def SaveTextAreas =
-  path    SavedTextAreas  []  ; 
-  path    SavedTextColumns[]  ; 
-  numeric NOfSavedTextAreas   ; 
-  numeric NOfSavedTextColumns ; 
+  path    SavedTextAreas  []  ;
+  path    SavedTextColumns[]  ;
+  numeric NOfSavedTextAreas   ;
+  numeric NOfSavedTextColumns ;
   for i=1 upto NOfTextAreas :
     SavedTextAreas[i] := TextAreas[i] ;
   endfor ;
@@ -50,177 +50,177 @@ def SaveTextAreas =
   NOfSavedTextColumns := NOfTextColumns ;
 enddef ;
 
-def ResetTextAreas = 
-  path TextAreas[], TextColumns[] ; 
-  numeric NOfTextAreas   ; NOfTextAreas   := 0 ;  
-  numeric NOfTextColumns ; NOfTextColumns := 0 ;  
+def ResetTextAreas =
+  path TextAreas[], TextColumns[] ;
+  numeric NOfTextAreas   ; NOfTextAreas   := 0 ;
+  numeric NOfTextColumns ; NOfTextColumns := 0 ;
   numeric nofmultipars   ; nofmultipars   := 0 ;
-  TextAreas[0] := TextColumns[0] := origin -- cycle ; 
-enddef ; 
+  TextAreas[0] := TextColumns[0] := origin -- cycle ;
+enddef ;
 
-ResetTextAreas ; SaveTextAreas ; ; 
+ResetTextAreas ; SaveTextAreas ; ;
 
-def RegisterTextArea (expr x, y, w, h, d) = 
-  begingroup ; save p ; path p ;  
+def RegisterTextArea (expr x, y, w, h, d) =
+  begingroup ; save p ; path p ;
     p := unitsquare xyscaled(w,h+d) shifted (x,y-d) ;
-    if NOfTextAreas>0 : 
-      % if needed, concatenate areas 
-      if (round(llcorner TextAreas[NOfTextAreas]) = round(ulcorner p)) and 
-         (round(lrcorner TextAreas[NOfTextAreas]) = round(urcorner p)) : 
+    if NOfTextAreas>0 :
+      % if needed, concatenate areas
+      if (round(llcorner TextAreas[NOfTextAreas]) = round(ulcorner p)) and
+         (round(lrcorner TextAreas[NOfTextAreas]) = round(urcorner p)) :
         p := ulcorner TextAreas[NOfTextAreas] --
              urcorner TextAreas[NOfTextAreas] --
              lrcorner p --
              llcorner p --
              cycle ;
-      else : 
-        NOfTextAreas := NOfTextAreas + 1 ; 
-      fi ; 
-    else : 
-      NOfTextAreas := NOfTextAreas + 1 ; 
-    fi ; 
+      else :
+        NOfTextAreas := NOfTextAreas + 1 ;
+      fi ;
+    else :
+      NOfTextAreas := NOfTextAreas + 1 ;
+    fi ;
     TextAreas[NOfTextAreas] := p ;
-    if NOfTextColumns>0 : 
-      if (round(xpart llcorner TextColumns[NOfTextColumns]) = round(xpart ulcorner p)) and 
-         (round(xpart lrcorner TextColumns[NOfTextColumns]) = round(xpart urcorner p)) : 
+    if NOfTextColumns>0 :
+      if (round(xpart llcorner TextColumns[NOfTextColumns]) = round(xpart ulcorner p)) and
+         (round(xpart lrcorner TextColumns[NOfTextColumns]) = round(xpart urcorner p)) :
         p := ulcorner TextColumns[NOfTextColumns] --
              urcorner TextColumns[NOfTextColumns] --
              lrcorner p --
              llcorner p --
              cycle ;
-      else : 
-        NOfTextColumns := NOfTextColumns + 1 ; 
-      fi ; 
-    else : 
-      NOfTextColumns := NOfTextColumns + 1 ; 
-    fi ; 
+      else :
+        NOfTextColumns := NOfTextColumns + 1 ;
+      fi ;
+    else :
+      NOfTextColumns := NOfTextColumns + 1 ;
+    fi ;
     TextColumns[NOfTextColumns] := p ;
-  endgroup ; 
-enddef ; 
+  endgroup ;
+enddef ;
 
-%D We store a local area in slot zero. 
+%D We store a local area in slot zero.
 
-def RegisterLocalTextArea (expr x, y, w, h, d) = 
+def RegisterLocalTextArea (expr x, y, w, h, d) =
   TextAreas[0] := TextColumns[0] := unitsquare xyscaled(w,h+d) shifted (x,y-d) ;
-enddef ; 
+enddef ;
 
 def ResetLocalTextArea =
-  TextAreas[0] := TextColumns[0] := origin -- cycle ; 
-enddef ; 
+  TextAreas[0] := TextColumns[0] := origin -- cycle ;
+enddef ;
 
 ResetLocalTextArea ;
 
-vardef InsideTextArea (expr _i_, _xy_) = 
-  ( (round(xpart _xy_) >= round(xpart llcorner TextAreas[_i_])) and 
-    (round(xpart _xy_) <= round(xpart lrcorner TextAreas[_i_])) and 
-    (round(ypart _xy_) >= round(ypart llcorner TextAreas[_i_])) and 
+vardef InsideTextArea (expr _i_, _xy_) =
+  ( (round(xpart _xy_) >= round(xpart llcorner TextAreas[_i_])) and
+    (round(xpart _xy_) <= round(xpart lrcorner TextAreas[_i_])) and
+    (round(ypart _xy_) >= round(ypart llcorner TextAreas[_i_])) and
     (round(ypart _xy_) <= round(ypart urcorner TextAreas[_i_])) )
-enddef ; 
+enddef ;
 
-vardef InsideSavedTextArea (expr _i_, _xy_) = 
-  ( (round(xpart _xy_) >= round(xpart llcorner SavedTextAreas[_i_])) and 
-    (round(xpart _xy_) <= round(xpart lrcorner SavedTextAreas[_i_])) and 
-    (round(ypart _xy_) >= round(ypart llcorner SavedTextAreas[_i_])) and 
+vardef InsideSavedTextArea (expr _i_, _xy_) =
+  ( (round(xpart _xy_) >= round(xpart llcorner SavedTextAreas[_i_])) and
+    (round(xpart _xy_) <= round(xpart lrcorner SavedTextAreas[_i_])) and
+    (round(ypart _xy_) >= round(ypart llcorner SavedTextAreas[_i_])) and
     (round(ypart _xy_) <= round(ypart urcorner SavedTextAreas[_i_])) )
-enddef ; 
+enddef ;
 
-vardef InsideSomeTextArea(expr _xy_) = 
-  save ok ; boolean ok ; ok := false ; 
-  for i := 1 upto NOfTextAreas : 
-    if InsideTextArea(i,_xy_) : ok := true ; fi ;  
-    exitif ok ; 
+vardef InsideSomeTextArea(expr _xy_) =
+  save ok ; boolean ok ; ok := false ;
+  for i := 1 upto NOfTextAreas :
+    if InsideTextArea(i,_xy_) : ok := true ; fi ;
+    exitif ok ;
   endfor ;
-  ok 
+  ok
 enddef ;
 
-vardef InsideSomeSavedTextArea(expr _xy_) = 
-  save ok ; boolean ok ; ok := false ; 
-  for i := 1 upto NOfSavedTextAreas : 
-    if InsideSavedTextArea(i,_xy_) : ok := true ; fi ;  
-    exitif ok ; 
+vardef InsideSomeSavedTextArea(expr _xy_) =
+  save ok ; boolean ok ; ok := false ;
+  for i := 1 upto NOfSavedTextAreas :
+    if InsideSavedTextArea(i,_xy_) : ok := true ; fi ;
+    exitif ok ;
   endfor ;
-  ok 
+  ok
 enddef ;
 
-vardef TextAreaX (expr x) = 
-  numeric _TextAreaX_ ; _TextAreaX_ := 0 ; 
-  for i := 1 upto NOfTextAreas : 
-    if (round(x) >= round(xpart llcorner TextAreas[i])) and 
-       (round(x) <= round(xpart lrcorner TextAreas[i])) : 
+vardef TextAreaX (expr x) =
+  numeric _TextAreaX_ ; _TextAreaX_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) :
       _TextAreaX_ := xpart llcorner TextAreas[i] ;
     fi ;
   endfor ;
-  _TextAreaX_ 
-enddef ; 
-
-vardef TextAreaY (expr y) = 
-  numeric _TextAreaY_ ; _TextAreaY_ := 0 ; 
-  for i := 1 upto NOfTextAreas : 
-    if (round(y) >= round(ypart llcorner TextAreas[NOfTextAreas])) and 
-       (round(y) <= round(ypart ulcorner TextAreas[NOfTextAreas])) : 
+  _TextAreaX_
+enddef ;
+
+vardef TextAreaY (expr y) =
+  numeric _TextAreaY_ ; _TextAreaY_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(y) >= round(ypart llcorner TextAreas[NOfTextAreas])) and
+       (round(y) <= round(ypart ulcorner TextAreas[NOfTextAreas])) :
       _TextAreaY_ := ypart llcorner TextAreas[NOfTextAreas] ;
     fi ;
   endfor ;
-  _TextAreaY_ 
-enddef ; 
-
-vardef TextAreaXY (expr x, y) = 
-  pair _TextAreaXY_ ; _TextAreaXY_ := origin ; 
-  for i := 1 upto NOfTextAreas : 
-    if (round(x) >= round(xpart llcorner TextAreas[i])) and 
-       (round(x) <= round(xpart lrcorner TextAreas[i])) and 
-       (round(y) >= round(ypart llcorner TextAreas[i])) and 
-       (round(y) <= round(ypart ulcorner TextAreas[i])) : 
+  _TextAreaY_
+enddef ;
+
+vardef TextAreaXY (expr x, y) =
+  pair _TextAreaXY_ ; _TextAreaXY_ := origin ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) and
+       (round(y) >= round(ypart llcorner TextAreas[i])) and
+       (round(y) <= round(ypart ulcorner TextAreas[i])) :
       _TextAreaXY_ := llconer TextAreas[i] ;
     fi ;
   endfor ;
-  _TextAreaXY_ 
-enddef ; 
-
-vardef TextAreaW (expr x) = 
-  numeric _TextAreaW_ ; _TextAreaW_ := 0 ; 
-  for i := 1 upto NOfTextAreas : 
-    if (round(x) >= round(xpart llcorner TextAreas[i])) and 
-       (round(x) <= round(xpart lrcorner TextAreas[i])) : 
+  _TextAreaXY_
+enddef ;
+
+vardef TextAreaW (expr x) =
+  numeric _TextAreaW_ ; _TextAreaW_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) :
       _TextAreaW_ := bbwidth(TextAreas[i]) ;
     fi ;
   endfor ;
-  _TextAreaW_ 
-enddef ; 
-
-vardef TextAreaH (expr y) = 
-  numeric _TextAreaH_ ; _TextAreaH_ := 0 ; 
-  for i := 1 upto NOfTextAreas : 
-    if (round(y) >= round(ypart llcorner TextAreas[i])) and 
-       (round(y) <= round(ypart ulcorner TextAreas[i])) : 
+  _TextAreaW_
+enddef ;
+
+vardef TextAreaH (expr y) =
+  numeric _TextAreaH_ ; _TextAreaH_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(y) >= round(ypart llcorner TextAreas[i])) and
+       (round(y) <= round(ypart ulcorner TextAreas[i])) :
       _TextAreaH_ := bbheight(TextAreas[i]) ;
     fi ;
   endfor ;
-  _TextAreaH_ 
-enddef ; 
-
-vardef TextAreaWH (expr x, y) = 
-  pair _TextAreaWH_ ; _TextAreaWH_ := origin ; 
-  for i := 1 upto NOfTextAreas : 
-    if (round(x) >= round(xpart llcorner TextAreas[i])) and 
-       (round(x) <= round(xpart lrcorner TextAreas[i])) and 
-       (round(y) >= round(ypart llcorner TextAreas[i])) and 
-       (round(y) <= round(ypart ulcorner TextAreas[i])) : 
+  _TextAreaH_
+enddef ;
+
+vardef TextAreaWH (expr x, y) =
+  pair _TextAreaWH_ ; _TextAreaWH_ := origin ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) and
+       (round(y) >= round(ypart llcorner TextAreas[i])) and
+       (round(y) <= round(ypart ulcorner TextAreas[i])) :
       _TextAreaWH_ := (bbwidth(TextAreas[i]),bbheight(TextAreas[i])) ;
     fi ;
   endfor ;
-  _TextAreaWH_ 
-enddef ; 
+  _TextAreaWH_
+enddef ;
 
-PageNumber          := 0 ; 
+PageNumber          := 0 ;
 PaperHeight         := 845.04684pt  ;
 PaperWidth          := 597.50787pt  ;
 PrintPaperHeight    := 845.04684pt  ;
 PrintPaperWidth     := 597.50787pt  ;
 TopSpace            :=  71.12546pt  ;
-BottomSpace         :=   0.0pt      ; 
+BottomSpace         :=   0.0pt      ;
 BackSpace           :=  71.13275pt  ;
 CutSpace            :=   0.0pt      ;
-MakeupHeight        := 711.3191pt   ; 
+MakeupHeight        := 711.3191pt   ;
 MakeupWidth         := 426.78743pt  ;
 TopHeight           :=   0.0pt      ;
 TopDistance         :=   0.0pt      ;
@@ -241,60 +241,60 @@ RightMarginWidth    :=   75.58197pt ;
 RightEdgeDistance   :=    0.0pt     ;
 RightEdgeWidth      :=    0.0pt     ;
 
-PageOffset          :=    0.0pt     ; 
-PageDepth           :=    0.0pt     ; 
+PageOffset          :=    0.0pt     ;
+PageDepth           :=    0.0pt     ;
 
 LayoutColumns       :=    0         ;
-LayoutColumnDistance:=    0.0pt     ;              
+LayoutColumnDistance:=    0.0pt     ;
 LayoutColumnWidth   :=    0.0pt     ;
 
 LeftEdge             :=  -4 ; Top             := -40 ;
-LeftEdgeSeparator    :=  -3 ; TopSeparator    := -30 ; 
-LeftMargin           :=  -2 ; Header          := -20 ; 
-LeftMarginSeparator  :=  -1 ; HeaderSeparator := -10 ; 
+LeftEdgeSeparator    :=  -3 ; TopSeparator    := -30 ;
+LeftMargin           :=  -2 ; Header          := -20 ;
+LeftMarginSeparator  :=  -1 ; HeaderSeparator := -10 ;
 Text                 :=   0 ; Text            :=   0 ;
-RightMarginSeparator :=  +1 ; FooterSeparator := +10 ; 
-RightMargin          :=  +2 ; Footer          := +20 ; 
-RightEdgeSeparator   :=  +3 ; BottomSeparator := +30 ; 
-RightEdge            :=  +4 ; Bottom          := +40 ; 
-
-Margin      := LeftMargin  ; % obsolete 
-Edge        := LeftEdge    ; % obsolete 
-InnerMargin := RightMargin ; % obsolete 
-InnerEdge   := RightEdge   ; % obsolete 
-OuterMargin := LeftMargin  ; % obsolete 
-OuterEdge   := LeftEdge    ; % obsolete 
- 
-InnerMarginWidth     := 0pt ; 
-OuterMarginWidth     := 0pt ; 
-InnerMarginDistance  := 0pt ; 
-OuterMarginDistance  := 0pt ; 
-
-InnerEdgeWidth     := 0pt ; 
-OuterEdgeWidth     := 0pt ; 
-InnerEdgeDistance  := 0pt ; 
-OuterEdgeDistance  := 0pt ; 
-
-path Area [][] ; pair Location [][] ; path Field [][] ;  path Page ; 
-numeric HorPos ; numeric Hstep [] ; numeric Hsize [] ; 
-numeric VerPos ; numeric Vstep [] ; numeric Vsize [] ; 
-
-for VerPos=Top step 10 until Bottom: 
-  for HorPos=LeftEdge step 1 until RightEdge: 
-    Area[HorPos][VerPos] := origin--cycle ; 
+RightMarginSeparator :=  +1 ; FooterSeparator := +10 ;
+RightMargin          :=  +2 ; Footer          := +20 ;
+RightEdgeSeparator   :=  +3 ; BottomSeparator := +30 ;
+RightEdge            :=  +4 ; Bottom          := +40 ;
+
+Margin      := LeftMargin  ; % obsolete
+Edge        := LeftEdge    ; % obsolete
+InnerMargin := RightMargin ; % obsolete
+InnerEdge   := RightEdge   ; % obsolete
+OuterMargin := LeftMargin  ; % obsolete
+OuterEdge   := LeftEdge    ; % obsolete
+
+InnerMarginWidth     := 0pt ;
+OuterMarginWidth     := 0pt ;
+InnerMarginDistance  := 0pt ;
+OuterMarginDistance  := 0pt ;
+
+InnerEdgeWidth     := 0pt ;
+OuterEdgeWidth     := 0pt ;
+InnerEdgeDistance  := 0pt ;
+OuterEdgeDistance  := 0pt ;
+
+path Area [][] ; pair Location [][] ; path Field [][] ;  path Page ;
+numeric HorPos ; numeric Hstep [] ; numeric Hsize [] ;
+numeric VerPos ; numeric Vstep [] ; numeric Vsize [] ;
+
+for VerPos=Top step 10 until Bottom:
+  for HorPos=LeftEdge step 1 until RightEdge:
+    Area[HorPos][VerPos] := origin--cycle ;
     Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
-    Location[HorPos][VerPos] := origin ;  
+    Location[HorPos][VerPos] := origin ;
     Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
-    Field[HorPos][VerPos] := origin--cycle ; 
+    Field[HorPos][VerPos] := origin--cycle ;
     Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
-  endfor ; 
-endfor ;  
+  endfor ;
+endfor ;
 
-% def LoadPageState = 
+% def LoadPageState =
 %   scantokens "input mp-state.tmp" ;
-% enddef ; 
+% enddef ;
 
-def SwapPageState = 
+def SwapPageState =
   if not OnRightPage :
            BackSpace := PaperWidth-MakeupWidth-BackSpace ;
             CutSpace := PaperWidth-MakeupWidth-CutSpace ;
@@ -311,137 +311,137 @@ def SwapPageState =
     LeftEdgeDistance := RightEdgeDistance ;
    RightEdgeDistance := i ;
 
-% these are now available as ..Width and ..Distance 
-
-              Margin := LeftMargin ; 
-                Edge := LeftEdge ; 
-         InnerMargin := RightMargin ; 
-           InnerEdge := RightEdge ; 
-         OuterMargin := LeftMargin ; 
-           OuterEdge := LeftEdge ; 
-  else : 
-              Margin := RightMargin ; 
-                Edge := RightEdge ; 
-         InnerMargin := LeftMargin ; 
-           InnerEdge := LeftEdge ; 
-         OuterMargin := RightMargin ; 
-           OuterEdge := RightEdge ; 
+% these are now available as ..Width and ..Distance
+
+              Margin := LeftMargin ;
+                Edge := LeftEdge ;
+         InnerMargin := RightMargin ;
+           InnerEdge := RightEdge ;
+         OuterMargin := LeftMargin ;
+           OuterEdge := LeftEdge ;
+  else :
+              Margin := RightMargin ;
+                Edge := RightEdge ;
+         InnerMargin := LeftMargin ;
+           InnerEdge := LeftEdge ;
+         OuterMargin := RightMargin ;
+           OuterEdge := RightEdge ;
   fi ;
-enddef ; 
+enddef ;
 
-def SetPageAreas = 
+def SetPageAreas =
 
   numeric Vsize[], Hsize[], Vstep[], Hstep[] ;
 
-  Vsize[Top]             = TopHeight ; 
-  Vsize[TopSeparator]    = TopDistance ; 
-  Vsize[Header]          = HeaderHeight ; 
-  Vsize[HeaderSeparator] = HeaderDistance ; 
-  Vsize[Text]            = TextHeight ; 
-  Vsize[FooterSeparator] = FooterDistance ; 
-  Vsize[Footer]          = FooterHeight ; 
-  Vsize[BottomSeparator] = BottomDistance ; 
-  Vsize[Bottom]          = BottomHeight ; 
+  Vsize[Top]             = TopHeight ;
+  Vsize[TopSeparator]    = TopDistance ;
+  Vsize[Header]          = HeaderHeight ;
+  Vsize[HeaderSeparator] = HeaderDistance ;
+  Vsize[Text]            = TextHeight ;
+  Vsize[FooterSeparator] = FooterDistance ;
+  Vsize[Footer]          = FooterHeight ;
+  Vsize[BottomSeparator] = BottomDistance ;
+  Vsize[Bottom]          = BottomHeight ;
 
   Vstep[Top]             = Vstep[TopSeparator]   +Vsize[TopSeparator] ;
-  Vstep[TopSeparator]    = PaperHeight-TopSpace ; 
-  Vstep[Header]          = Vstep[TopSeparator]   -Vsize[Header] ; 
-  Vstep[HeaderSeparator] = Vstep[Header]         -Vsize[HeaderSeparator] ; 
-  Vstep[Text]            = Vstep[HeaderSeparator]-Vsize[Text] ; 
-  Vstep[FooterSeparator] = Vstep[Text]           -Vsize[FooterSeparator] ; 
-  Vstep[Footer]          = Vstep[FooterSeparator]-Vsize[Footer] ; 
+  Vstep[TopSeparator]    = PaperHeight-TopSpace ;
+  Vstep[Header]          = Vstep[TopSeparator]   -Vsize[Header] ;
+  Vstep[HeaderSeparator] = Vstep[Header]         -Vsize[HeaderSeparator] ;
+  Vstep[Text]            = Vstep[HeaderSeparator]-Vsize[Text] ;
+  Vstep[FooterSeparator] = Vstep[Text]           -Vsize[FooterSeparator] ;
+  Vstep[Footer]          = Vstep[FooterSeparator]-Vsize[Footer] ;
   Vstep[BottomSeparator] = Vstep[Footer]         -Vsize[BottomSeparator] ;
-  Vstep[Bottom]          = Vstep[BottomSeparator]-Vsize[Bottom] ; 
+  Vstep[Bottom]          = Vstep[BottomSeparator]-Vsize[Bottom] ;
 
   Hsize[LeftEdge]             = LeftEdgeWidth ;
   Hsize[LeftEdgeSeparator]    = LeftEdgeDistance ;
   Hsize[LeftMargin]           = LeftMarginWidth ;
   Hsize[LeftMarginSeparator]  = LeftMarginDistance ;
-  Hsize[Text]                 = MakeupWidth ; 
-  Hsize[RightMarginSeparator] = RightMarginDistance ; 
-  Hsize[RightMargin]          = RightMarginWidth ; 
+  Hsize[Text]                 = MakeupWidth ;
+  Hsize[RightMarginSeparator] = RightMarginDistance ;
+  Hsize[RightMargin]          = RightMarginWidth ;
   Hsize[RightEdgeSeparator]   = RightEdgeDistance ;
-  Hsize[RightEdge]            = RightEdgeWidth ; 
+  Hsize[RightEdge]            = RightEdgeWidth ;
 
   Hstep[LeftEdge]             = Hstep[LeftEdgeSeparator]   -Hsize[LeftEdge] ;
   Hstep[LeftEdgeSeparator]    = Hstep[LeftMargin]          -Hsize[LeftEdgeSeparator] ;
   Hstep[LeftMargin]           = Hstep[LeftMarginSeparator] -Hsize[LeftMargin] ;
   Hstep[LeftMarginSeparator]  = Hstep[Text]                -Hsize[LeftMarginSeparator] ;
-  Hstep[Text]                 = BackSpace ; 
-  Hstep[RightMarginSeparator] = Hstep[Text]                +Hsize[Text] ; 
+  Hstep[Text]                 = BackSpace ;
+  Hstep[RightMarginSeparator] = Hstep[Text]                +Hsize[Text] ;
   Hstep[RightMargin]          = Hstep[RightMarginSeparator]+Hsize[RightMarginSeparator] ;
   Hstep[RightEdgeSeparator]   = Hstep[RightMargin]         +Hsize[RightMargin] ;
-  Hstep[RightEdge]            = Hstep[RightEdgeSeparator]  +Hsize[RightEdgeSeparator] ; 
+  Hstep[RightEdge]            = Hstep[RightEdgeSeparator]  +Hsize[RightEdgeSeparator] ;
 
-  for VerPos=Top step 10 until Bottom: 
-    for HorPos=LeftEdge step 1 until RightEdge: 
-      Area[HorPos][VerPos] := unitsquare xscaled Hsize[HorPos] yscaled Vsize[VerPos] ; 
+  for VerPos=Top step 10 until Bottom:
+    for HorPos=LeftEdge step 1 until RightEdge:
+      Area[HorPos][VerPos] := unitsquare xscaled Hsize[HorPos] yscaled Vsize[VerPos] ;
       Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
-      Location[HorPos][VerPos] := (Hstep[HorPos],Vstep[VerPos]) ;  
+      Location[HorPos][VerPos] := (Hstep[HorPos],Vstep[VerPos]) ;
       Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
       Field[HorPos][VerPos] := Area[HorPos][VerPos] shifted Location[HorPos][VerPos] ;
       Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
-    endfor ; 
-  endfor ; 
+    endfor ;
+  endfor ;
 
-  Page := unitsquare xscaled PaperWidth yscaled PaperHeight ;  
+  Page := unitsquare xscaled PaperWidth yscaled PaperHeight ;
 
-enddef ; 
+enddef ;
 
 def BoundPageAreas =
 
- % pickup pencircle scaled 0pt ; 
+ % pickup pencircle scaled 0pt ;
 
   bboxmargin := 0 ; setbounds currentpicture to Page ;
 
-enddef ; 
+enddef ;
 
 def StartPage =
 
-  if PageStateAvailable : 
-    LoadPageState ; 
+  if PageStateAvailable :
+    LoadPageState ;
     SwapPageState ;
-  fi ; 
- 
+  fi ;
+
   SetPageAreas ;
   BoundPageAreas ;
 
-enddef ; 
+enddef ;
 
 def StopPage =
 
   BoundPageAreas ;
 
-enddef ; 
+enddef ;
+
+def OverlayBox =
+  (unitsquare xyscaled (OverlayWidth,OverlayHeight))
+enddef ;
 
-def OverlayBox = 
-  (unitsquare xyscaled (OverlayWidth,OverlayHeight)) 
-enddef ; 
+% handy
 
-% handy 
+def innerenlarged =
+  hide(LoadPageState)
+  if OnRightPage : leftenlarged  else : rightenlarged fi
+enddef ;
 
-def innerenlarged = 
-  hide(LoadPageState) 
-  if OnRightPage : leftenlarged  else : rightenlarged fi 
-enddef ;   
-  
-def outerenlarged = 
+def outerenlarged =
   hide(LoadPageState)
-  if OnRightPage : rightenlarged else : leftenlarged  fi 
-enddef ;   
+  if OnRightPage : rightenlarged else : leftenlarged  fi
+enddef ;
 
 % obsolete
 
-def llEnlarged (expr p,d) = (llcorner p shifted (-d,-d)) enddef ; 
-def lrEnlarged (expr p,d) = (lrcorner p shifted (+d,-d)) enddef ; 
-def urEnlarged (expr p,d) = (urcorner p shifted (+d,+d)) enddef ; 
-def ulEnlarged (expr p,d) = (ulcorner p shifted (-d,+d)) enddef ; 
+def llEnlarged (expr p,d) = (llcorner p shifted (-d,-d)) enddef ;
+def lrEnlarged (expr p,d) = (lrcorner p shifted (+d,-d)) enddef ;
+def urEnlarged (expr p,d) = (urcorner p shifted (+d,+d)) enddef ;
+def ulEnlarged (expr p,d) = (ulcorner p shifted (-d,+d)) enddef ;
 
-def Enlarged (expr p, d) = 
+def Enlarged (expr p, d) =
   (llEnlarged (p,d) --
    lrEnlarged (p,d) --
    urEnlarged (p,d) --
-   ulEnlarged (p,d) -- cycle) 
-enddef ; 
+   ulEnlarged (p,d) -- cycle)
+enddef ;
 
-endinput ; 
+endinput ;
\ No newline at end of file
diff --git a/metapost/context/base/mp-spec.mp b/metapost/context/base/mp-spec.mp
index 3563e982e..b005eb381 100644
--- a/metapost/context/base/mp-spec.mp
+++ b/metapost/context/base/mp-spec.mp
@@ -12,13 +12,13 @@
 %C details.
 
 % Spot colors are not handled by mptopdf !
-                                         
+
 % (r,g,b) => cmyk             : r=123 g=   1 b=hash
-%         => spot             : r=123 g=   2 b=hash 
+%         => spot             : r=123 g=   2 b=hash
 %         => transparent rgb  : r=123 g=   3 b=hash
 %         => transparent cmyk : r=123 g=   4 b=hash
 %         => transparent spot : r=123 g=   5 b=hash
-%         => rest             : r=123 g=n>10 b=whatever 
+%         => rest             : r=123 g=n>10 b=whatever
 
 %D This module is rather preliminary and subjected to
 %D changes. Here we closely cooperates with the \METAPOST\
@@ -32,7 +32,7 @@ if   known context_spec : endinput         ; fi ;
 boolean context_spec ; context_spec := true ;
 
 numeric _special_counter_ ; _special_counter_ :=   0 ;
-numeric _color_counter_   ; _color_counter_   :=  11 ; % < 10 reserved  
+numeric _color_counter_   ; _color_counter_   :=  11 ; % < 10 reserved
 numeric _special_signal_  ; _special_signal_  := 123 ;
 
 %D When set to \type {true}, shading will be supported. Some
@@ -49,7 +49,7 @@ string _global_specials_ ; _global_specials_ := "" ;
 string _local_specials_  ; _local_specials_  := "" ;
 
 vardef add_special_signal = % write the version number
-  if (length _global_specials_>0) or (length _local_specials_ >0) : 
+  if (length _global_specials_>0) or (length _local_specials_ >0) :
     special ("%%MetaPostSpecials: 1.0 " & decimal _special_signal_ ) ;
   fi ;
 enddef ;
@@ -60,33 +60,33 @@ vardef add_extra_specials =
 enddef ;
 
 vardef reset_extra_specials =
-  % only local ones 
+  % only local ones
   _local_specials_ := "" ;
 enddef ;
 
 boolean insidefigure ; insidefigure := false ;
 
-% todo: alleen als special gebruikt flush 
+% todo: alleen als special gebruikt flush
 
-extra_beginfig := 
-  " insidefigure := true ; " & 
-  " reset_extra_specials ; " & 
-    extra_beginfig ;  
+extra_beginfig :=
+  " insidefigure := true ; " &
+  " reset_extra_specials ; " &
+    extra_beginfig ;
 
 extra_endfig :=
   " add_special_signal ; "    &
     extra_endfig              &
   " add_extra_specials ; "    &
-  " reset_extra_specials ; "  & 
+  " reset_extra_specials ; "  &
   " insidefigure := false ; " ;
 
-def set_extra_special (expr s) = 
-  if insidefigure : 
-    _local_specials_  := _local_specials_  & s ; 
-  else : 
-    _global_specials_ := _global_specials_ & s ; 
-  fi 
-enddef ; 
+def set_extra_special (expr s) =
+  if insidefigure :
+    _local_specials_  := _local_specials_  & s ;
+  else :
+    _global_specials_ := _global_specials_ & s ;
+  fi
+enddef ;
 
 def flush_special (expr typ, siz, dat) =
   _special_counter_ := _special_counter_ + 1 ;
@@ -99,7 +99,7 @@ def flush_special (expr typ, siz, dat) =
       & decimal typ & " "
       & decimal siz
       & " special"
-      & ditto & ");" ) ; 
+      & ditto & ");" ) ;
   else :
     set_extra_special
       ( "special "
@@ -115,12 +115,12 @@ enddef ;
 
 %D The next hack is needed in case you use a version of
 %D \METAPOST\ that does not provide you the means to configure
-%D the buffer size. Patrick Gundlach suggested to use arrays 
-%D in this case. 
+%D the buffer size. Patrick Gundlach suggested to use arrays
+%D in this case.
 
-boolean bufferhack ; bufferhack := false ; % true ; 
+boolean bufferhack ; bufferhack := false ; % true ;
 
-if bufferhack : 
+if bufferhack :
 
   string _global_specials_[] ; numeric _nof_global_specials_ ;
   string _local_specials_[]  ; numeric _nof_local_specials_ ;
@@ -128,17 +128,17 @@ if bufferhack :
   _nof_global_specials_ := _nof_local_specials_ := 0 ;
 
   vardef add_special_signal = % write the version number
-    if (_nof_global_specials_>0) or (_nof_local_specials_>0) : 
+    if (_nof_global_specials_>0) or (_nof_local_specials_>0) :
       special ("%%MetaPostSpecials: 1.0 " & decimal _special_signal_ ) ;
     fi ;
   enddef ;
- 
+
   vardef add_extra_specials =
-    for i=1 upto _nof_global_specials_ : 
-      scantokens _global_specials_[i] ; 
+    for i=1 upto _nof_global_specials_ :
+      scantokens _global_specials_[i] ;
     endfor;
-    for i=1 upto _nof_local_specials_ : 
-      scantokens _local_specials_[i] ;   
+    for i=1 upto _nof_local_specials_ :
+      scantokens _local_specials_[i] ;
     endfor;
   enddef ;
 
@@ -146,27 +146,27 @@ if bufferhack :
     string _local_specials_[]  ; _nof_local_specials_ := 0 ;
   enddef ;
 
-  def set_extra_special (expr s) = 
-    if insidefigure : 
-      _local_specials_[incr(_nof_local_specials_)]   := s ;   
-    else : 
+  def set_extra_special (expr s) =
+    if insidefigure :
+      _local_specials_[incr(_nof_local_specials_)]   := s ;
+    else :
       _global_specials_[incr(_nof_global_specials_)] := s ;
-    fi 
-  enddef ; 
+    fi
+  enddef ;
 
-fi ; 
+fi ;
 
-%D So far for this hack. 
+%D So far for this hack.
 
 %D Shade allocation.
 
-newinternal shadefactor ; shadefactor := 1 ; 
+newinternal shadefactor ; shadefactor := 1 ;
 
-pair shadeoffset ; shadeoffset := origin ; 
+pair shadeoffset ; shadeoffset := origin ;
 
 vardef define_linear_shade (expr a, b, ca, cb) =
   flush_special(30, 15, "0 1 " & decimal shadefactor & " " &
-    dddecimal ca & " " & ddecimal (a shifted shadeoffset) & " " & 
+    dddecimal ca & " " & ddecimal (a shifted shadeoffset) & " " &
     dddecimal cb & " " & ddecimal (b shifted shadeoffset) ) ;
   _special_counter_
 enddef ;
@@ -188,32 +188,32 @@ boolean trace_shades ; trace_shades := false ;
 %  else         : a := llcorner p ; b := lrcorner p ;
 %  fi ;
 
-def set_linear_vector (suffix a,b)(expr p,n) = 
-  if     (n=1) : a := llcorner p ; 
+def set_linear_vector (suffix a,b)(expr p,n) =
+  if     (n=1) : a := llcorner p ;
                  b := urcorner p ;
-  elseif (n=2) : a := lrcorner p ; 
+  elseif (n=2) : a := lrcorner p ;
                  b := ulcorner p ;
-  elseif (n=3) : a := urcorner p ; 
+  elseif (n=3) : a := urcorner p ;
                  b := llcorner p ;
-  elseif (n=4) : a := ulcorner p ; 
+  elseif (n=4) : a := ulcorner p ;
                  b := lrcorner p ;
-  elseif (n=5) : a := .5[ulcorner p,llcorner p] ; 
-                 b := .5[urcorner p,lrcorner p] ; 
-  elseif (n=6) : a := .5[llcorner p,lrcorner p] ; 
-                 b := .5[ulcorner p,urcorner p] ; 
-  elseif (n=7) : a := .5[lrcorner p,urcorner p] ; 
-                 b := .5[llcorner p,ulcorner p] ; 
-  elseif (n=8) : a := .5[urcorner p,ulcorner p] ; 
-                 b := .5[lrcorner p,llcorner p] ; 
-  else         : a := .5[ulcorner p,llcorner p] ; 
-                 b := .5[urcorner p,lrcorner p] ; 
+  elseif (n=5) : a := .5[ulcorner p,llcorner p] ;
+                 b := .5[urcorner p,lrcorner p] ;
+  elseif (n=6) : a := .5[llcorner p,lrcorner p] ;
+                 b := .5[ulcorner p,urcorner p] ;
+  elseif (n=7) : a := .5[lrcorner p,urcorner p] ;
+                 b := .5[llcorner p,ulcorner p] ;
+  elseif (n=8) : a := .5[urcorner p,ulcorner p] ;
+                 b := .5[lrcorner p,llcorner p] ;
+  else         : a := .5[ulcorner p,llcorner p] ;
+                 b := .5[urcorner p,lrcorner p] ;
   fi ;
-enddef ; 
+enddef ;
 
 def linear_shade (expr p, n, ca, cb) =
   begingroup ;
   save a, b, sh ; pair a, b ;
-  set_linear_vector(a,b)(p,n) ; 
+  set_linear_vector(a,b)(p,n) ;
   fill p withshade define_linear_shade (a,b,ca,cb) ;
   if trace_shades :
     drawarrow a -- b withpen pencircle scaled 1pt ;
@@ -223,26 +223,26 @@ enddef ;
 
 vardef predefined_linear_shade (expr p, n, ca, cb) =
   save a, b, sh ; pair a, b ;
-  set_linear_vector(a,b)(p,n) ; 
+  set_linear_vector(a,b)(p,n) ;
   set_shade_vector(a,b)(p,n) ;
-  define_linear_shade (a,b,ca,cb) 
+  define_linear_shade (a,b,ca,cb)
 enddef ;
 
-def set_circular_vector (suffix ab, r)(expr p,n) = 
+def set_circular_vector (suffix ab, r)(expr p,n) =
   if     (n=1) : ab := llcorner p ;
   elseif (n=2) : ab := lrcorner p ;
   elseif (n=3) : ab := urcorner p ;
   elseif (n=4) : ab := ulcorner p ;
   else         : ab := center   p ; r := .5r ;
   fi ;
-enddef ; 
+enddef ;
 
 def circular_shade (expr p, n, ca, cb) =
   begingroup ;
   save ab, r ; pair ab ; numeric r ;
   r := (xpart lrcorner p - xpart llcorner p) ++
        (ypart urcorner p - ypart lrcorner p) ;
-  set_circular_vector(ab,r)(p,n) ; 
+  set_circular_vector(ab,r)(p,n) ;
   fill p withshade define_circular_shade(ab,ab,0,r,ca,cb) ;
   if trace_shades :
     drawarrow ab -- ab shifted (0,r) withpen pencircle scaled 1pt ;
@@ -254,14 +254,14 @@ vardef predefined_circular_shade (expr p, n, ca, cb) =
   save ab, r ; pair ab ; numeric r ;
   r := (xpart lrcorner p - xpart llcorner p) ++
        (ypart urcorner p - ypart lrcorner p) ;
-  set_circular_vector(ab,r)(p,n) ; 
-  define_circular_shade(ab,ab,0,r,ca,cb) 
+  set_circular_vector(ab,r)(p,n) ;
+  define_circular_shade(ab,ab,0,r,ca,cb)
 enddef ;
 
 %D Since a \type {fill p withshade s} syntax looks better
 %D than some macro, we implement a new primary.
 
-primarydef p withshade sc = % == p withcolor shadecolor(sh) 
+primarydef p withshade sc = % == p withcolor shadecolor(sh)
   hide (_color_counter_ := _color_counter_ + 1)
   p withcolor (_special_signal_/1000,_color_counter_/1000,sc/1000)
 enddef ;
@@ -287,7 +287,7 @@ def doexternalfigure (expr filename) text transformation =
     dddecimal (yypart t,  xpart t,  ypart t) & " " & filename) ;
   addto p contour unitsquare scaled 0 ;
   setbounds p to unitsquare transformed t ;
-  _color_counter_ := _color_counter_ + 1 ; 
+  _color_counter_ := _color_counter_ + 1 ;
   draw p withcolor (_special_signal_/1000,_color_counter_/1000,_special_counter_/1000) ;
 %draw p withcolor (_special_signal_/1000,cef/1000,_special_counter_/1000) ;
   endgroup ;
@@ -365,27 +365,27 @@ enddef ;
 
 resetcmykcolors ; boolean cmykcolors ; cmykcolors := false ; % true
 
-string cmykcolorpattern[] ; % needed for transparancies 
+string cmykcolorpattern[] ; % needed for transparancies
 
 vardef cmyk(expr c,m,y,k) =
   if cmykcolors :
-    save ok ; boolean ok ; 
+    save ok ; boolean ok ;
     if unknown cmykcolorhash[c][m][y][k] :
-      ok := false ; % not yet defined 
-    elseif cmykcolorhash[c][m][y][k] = -1 : 
-      ok := false ; % locally defined and undefined  
-    else : 
-      ok := true ;  % globally already defined 
-    fi ; 
-    if not ok : 
+      ok := false ; % not yet defined
+    elseif cmykcolorhash[c][m][y][k] = -1 :
+      ok := false ; % locally defined and undefined
+    else :
+      ok := true ;  % globally already defined
+    fi ;
+    if not ok :
       save s ; string s ; s := dddecimal (c,m,y) & " " & decimal k ;
       _cmyk_counter_ := _cmyk_counter_ + 1 ;
-      cmykcolorpattern[_cmyk_counter_/1000] := s ;  
+      cmykcolorpattern[_cmyk_counter_/1000] := s ;
       cmykcolorhash[c][m][y][k] := _cmyk_counter_ ;
-      flush_special(1, 7, decimal _cmyk_counter_ & " " & s) ; 
-      _local_specials_ := _local_specials_ & 
-        " cmykcolorhash[" & decimal c & "][" & decimal m & 
-        "][" & decimal y & "][" & decimal k & "] := -1 ; " ; 
+      flush_special(1, 7, decimal _cmyk_counter_ & " " & s) ;
+      _local_specials_ := _local_specials_ &
+        " cmykcolorhash[" & decimal c & "][" & decimal m &
+        "][" & decimal y & "][" & decimal k & "] := -1 ; " ;
     fi ;
     (_special_signal_/1000,1/1000,cmykcolorhash[c][m][y][k]/1000)
   else :
@@ -393,11 +393,11 @@ vardef cmyk(expr c,m,y,k) =
   fi
 enddef ;
 
-% newcolor truecyan, truemagenta, trueyellow ; 
+% newcolor truecyan, truemagenta, trueyellow ;
 %
-% truecyan    = cmyk (1,0,0,0) ; 
-% truemagenta = cmyk (0,1,0,0) ; 
-% trueyellow  = cmyk (0,0,1,0) ; 
+% truecyan    = cmyk (1,0,0,0) ;
+% truemagenta = cmyk (0,1,0,0) ;
+% trueyellow  = cmyk (0,0,1,0) ;
 
 %D Spot colors
 
@@ -412,32 +412,32 @@ enddef ;
 
 resetspotcolors ; boolean spotcolors ; spotcolors := false ; % true
 
-string spotcolorpattern[] ; % needed for transparancies 
+string spotcolorpattern[] ; % needed for transparancies
 
 vardef spotcolor(expr p, s) =
   if spotcolors :
-    save ok, pc_tag ; boolean ok ; string pc_tag ; 
-    pc_tag := "_pct_"&p ; 
-    if not unstringed(pc_tag) : 
-      _spotcolor_number_ := _spotcolor_number_ + 1 ; 
-      setunstringed(pc_tag,_spotcolor_number_) ; 
-    fi ; 
-    pp := getunstringed(pc_tag) ; 
+    save ok, pc_tag ; boolean ok ; string pc_tag ;
+    pc_tag := "_pct_"&p ;
+    if not unstringed(pc_tag) :
+      _spotcolor_number_ := _spotcolor_number_ + 1 ;
+      setunstringed(pc_tag,_spotcolor_number_) ;
+    fi ;
+    pp := getunstringed(pc_tag) ;
     if unknown spotcolorhash[pp][s] :
-      ok := false ; % not yet defined 
-    elseif spotcolorhash[pp][s] = -1 : 
-      ok := false ; % locally defined and undefined  
-    else : 
-      ok := true ;  % globally already defined 
-    fi ; 
-    if not ok : 
+      ok := false ; % not yet defined
+    elseif spotcolorhash[pp][s] = -1 :
+      ok := false ; % locally defined and undefined
+    else :
+      ok := true ;  % globally already defined
+    fi ;
+    if not ok :
       save ss ; string ss ; ss := p & " " & decimal s ;
       _spotcolor_counter_ := _spotcolor_counter_ + 1 ;
-      spotcolorpattern[_spotcolor_counter_/1000] := ss ;  
+      spotcolorpattern[_spotcolor_counter_/1000] := ss ;
       spotcolorhash[pp][s] := _spotcolor_counter_ ;
-      flush_special(2, 5, decimal _spotcolor_counter_ & " " & ss) ; 
-      _local_specials_ := _local_specials_ & 
-        "spotcolorhash["&decimal pp&"]["&decimal s&"]:=-1;" ;  
+      flush_special(2, 5, decimal _spotcolor_counter_ & " " & ss) ;
+      _local_specials_ := _local_specials_ &
+        "spotcolorhash["&decimal pp&"]["&decimal s&"]:=-1;" ;
     fi ;
     (_special_signal_/1000,2/1000,spotcolorhash[pp][s]/1000)
   else :
@@ -445,19 +445,19 @@ vardef spotcolor(expr p, s) =
   fi
 enddef ;
 
-%D Transparency 
+%D Transparency
 
-normaltransparent     :=  1 ; multiplytransparent   :=  2 ; 
-screentransparent     :=  3 ; overlaytransparent    :=  4 ; 
-softlighttransparent  :=  5 ; hardlighttransparent  :=  6 ; 
-colordodgetransparent :=  7 ; colorburntransparent  :=  8 ; 
-darkentransparent     :=  9 ; lightentransparent    := 10 ; 
-differencetransparent := 11 ; exclusiontransparent  := 12 ; 
+normaltransparent     :=  1 ; multiplytransparent   :=  2 ;
+screentransparent     :=  3 ; overlaytransparent    :=  4 ;
+softlighttransparent  :=  5 ; hardlighttransparent  :=  6 ;
+colordodgetransparent :=  7 ; colorburntransparent  :=  8 ;
+darkentransparent     :=  9 ; lightentransparent    := 10 ;
+differencetransparent := 11 ; exclusiontransparent  := 12 ;
 
-% nottransparent        :=  0 ; 
-% compatibletransparent := 99 ; 
+% nottransparent        :=  0 ;
+% compatibletransparent := 99 ;
 
-% fill fullcircle scaled 10cm withcolor transparant(.8,3,color) ; 
+% fill fullcircle scaled 10cm withcolor transparant(.8,3,color) ;
 
 vardef transparent(expr n, t, c) =
   save s, ss, nn, cc, is_cmyk, is_spot, ok ;
@@ -480,32 +480,32 @@ vardef transparent(expr n, t, c) =
   is_spot := (redpart   cc = _special_signal_/1000)
          and (greenpart cc = 2/1000) ;
   % build special string, fetch cmyk components
-  s := decimal nn & " " & decimal t & " " & 
-       if     is_cmyk : cmykcolorpattern[bluepart cc] 
-       elseif is_spot : spotcolorpattern[bluepart cc] 
+  s := decimal nn & " " & decimal t & " " &
+       if     is_cmyk : cmykcolorpattern[bluepart cc]
+       elseif is_spot : spotcolorpattern[bluepart cc]
        else           : dddecimal cc fi ;
   % check if this one is already used
   ss := "tr_" & s ;
   % efficiency hack
   if expandafter unknown scantokens(ss) :
-    ok := false ; % not yet defined 
-  elseif scantokens(ss) < 0  :  
-    ok := false ; % locally defined and undefined  
-  else : 
-    ok := true ;  % globally already defined 
-  fi ; 
-  if not ok : 
+    ok := false ; % not yet defined
+  elseif scantokens(ss) < 0  :
+    ok := false ; % locally defined and undefined
+  else :
+    ok := true ;  % globally already defined
+  fi ;
+  if not ok :
     if is_spot  :
       flush_special(5, 6, s) ;
     elseif is_cmyk :
       flush_special(4, 8, s) ;
-    else : 
+    else :
       flush_special(3, 7, s) ;
     fi ;
     scantokens(ss) := _special_counter_ ;
-    _local_specials_ := _local_specials_ & 
-      "scantokens(" & ditto & ss & ditto & ") := -1 ;" ; 
-  fi ; 
+    _local_specials_ := _local_specials_ &
+      "scantokens(" & ditto & ss & ditto & ") := -1 ;" ;
+  fi ;
   % go ahead
   if is_spot :
     (_special_signal_/1000,5/1000,scantokens(ss)/1000)
@@ -518,21 +518,21 @@ enddef ;
 
 %D This function returns true of false, dependent on transparency.
 
-vardef is_transparent(text t) = 
-  begingroup ; save transparent ; save _c_, _b_ ; 
+vardef is_transparent(text t) =
+  begingroup ; save transparent ; save _c_, _b_ ;
     vardef transparent(expr nn, tt, cc) = _b_ := true ; cc enddef ;
-    boolean _b_ ; _b_ := false ; 
-    color _c_ ; _c_ := t ; _b_ 
-  endgroup  
+    boolean _b_ ; _b_ := false ;
+    color _c_ ; _c_ := t ; _b_
+  endgroup
 enddef ;
 
-%D This function returns the not transparent color. 
+%D This function returns the not transparent color.
 
-vardef not_transparent(text t) = 
-  begingroup ; save transparent ; 
+vardef not_transparent(text t) =
+  begingroup ; save transparent ;
   vardef transparent(expr nn, tt, cc) = cc enddef ;
-  t endgroup 
-enddef ; 
+  t endgroup
+enddef ;
 
 %D Basic position tracking:
 
@@ -545,19 +545,19 @@ def register (expr label, width, height, offset) =
   endgroup ;
 enddef ;
 
-%D We cannot scale cmyk colors directly since this spoils 
-%D the trigger signal (such colors are no real colors). 
+%D We cannot scale cmyk colors directly since this spoils
+%D the trigger signal (such colors are no real colors).
 
 vardef scaledcmyk(expr c,m,y,k,sf) =
-  cmyk(sf*c,sf*m,sf*y,sf*k) 
+  cmyk(sf*c,sf*m,sf*y,sf*k)
 enddef ;
 
 vardef scaledcmykasrgb(expr c,m,y,k,sf) =
-  (sf*(1-c-k,1-m-k,1-y-k)) 
+  (sf*(1-c-k,1-m-k,1-y-k))
 enddef ;
 
 vardef scaledrgbascmyk(expr c,m,y,k,sf) =
-  scaledcmyk(1-c,1-m,1-y,0,sf) 
+  scaledcmyk(1-c,1-m,1-y,0,sf)
 enddef ;
 
 vardef scaledrgb(expr r,g,b,sf) =
@@ -568,6 +568,6 @@ vardef scaledgray(expr s,sf) =
   (sf*(s,s,s))
 enddef ;
 
-% spotcolor is already scaled 
+% spotcolor is already scaled
 
-endinput ;
+endinput ;
\ No newline at end of file
diff --git a/metapost/context/base/mp-tool.mp b/metapost/context/base/mp-tool.mp
index 9f2464e64..19160ba32 100644
--- a/metapost/context/base/mp-tool.mp
+++ b/metapost/context/base/mp-tool.mp
@@ -28,26 +28,26 @@ warningcheck := 0 ;
 
 %D Namespace handling:
 
-% let exclamationmark = ! ; 
-% let questionmark    = ? ; 
-% 
-% def unprotect = 
-%   let ! = relax ; 
-%   let ? = relax ; 
+% let exclamationmark = ! ;
+% let questionmark    = ? ;
+%
+% def unprotect =
+%   let ! = relax ;
+%   let ? = relax ;
 % enddef ;
-% 
-% def protect = 
+%
+% def protect =
 %   let ! = exclamationmark ;
-%   let ? = questionmark ; 
-% enddef ; 
-% 
-% unprotect ; 
-% 
-% mp!some!module = 10 ; show mp!some!module ; show somemodule ; 
-% 
+%   let ? = questionmark ;
+% enddef ;
+%
+% unprotect ;
+%
+% mp!some!module = 10 ; show mp!some!module ; show somemodule ;
+%
 % protect ;
 
-%D A semicolor to be used in specials: ? ? ? 
+%D A semicolor to be used in specials: ? ? ?
 
 string semicolor ; semicolor := char 59 ;
 
@@ -55,12 +55,12 @@ string semicolor ; semicolor := char 59 ;
 %D high resolution boundingbox to the \POSTSCRIPT\ file. This
 %D hack is due to John Hobby himself.
 
-% When somehow the first one gets no HiRes, then make sure 
-% that the format matches the mem sizes in the config file. 
+% When somehow the first one gets no HiRes, then make sure
+% that the format matches the mem sizes in the config file.
 
-% eerste " " er uit 
+% eerste " " er uit
 
-string space ; space = char 32 ; 
+string space ; space = char 32 ;
 
 vardef ddecimal primary p =
   decimal xpart p & " " & decimal ypart p
@@ -99,43 +99,43 @@ enddef ;
 %D Because \METAPOST\ has a hard coded limit of 4~datafiles,
 %D we need some trickery when we have multiple files.
 
-if unknown collapse_data : 
-  boolean collapse_data ; collapse_data := false ; 
-fi ; 
+if unknown collapse_data :
+  boolean collapse_data ; collapse_data := false ;
+fi ;
 
-boolean savingdata ; savingdata := false ; 
+boolean savingdata ; savingdata := false ;
 
 def savedata expr txt =
-  if collapse_data : 
+  if collapse_data :
     write if savingdata : txt else :
-      "\MPdata{" & decimal charcode & "}{" & txt & "}" 
-    fi 
+      "\MPdata{" & decimal charcode & "}{" & txt & "}"
+    fi
     & "%" to jobname & _data_suffix_ ;
-  else : 
+  else :
     write txt to data_file ;
-  fi ; 
+  fi ;
 enddef ;
 
-def startsavingdata = 
-  savingdata := true ; 
-  if collapse_data : 
-    write 
-      "\MPdata{" & decimal charcode & "}{%" 
-    to 
+def startsavingdata =
+  savingdata := true ;
+  if collapse_data :
+    write
+      "\MPdata{" & decimal charcode & "}{%"
+    to
       jobname & _data_suffix_ ;
-  fi ; 
+  fi ;
 enddef ;
 
-def stopsavingdata = 
-  savingdata := false ; 
-  if collapse_data : 
+def stopsavingdata =
+  savingdata := false ;
+  if collapse_data :
     write "}%" to jobname & _data_suffix_ ;
-  fi ; 
+  fi ;
 enddef ;
 
-%D Instead of a keystroke eating save and allocation 
-%D sequence, you can use the \citeer {new} alternatives to 
-%D save and allocate in one command. 
+%D Instead of a keystroke eating save and allocation
+%D sequence, you can use the \citeer {new} alternatives to
+%D save and allocate in one command.
 
 def newcolor     text v = forsuffixes i=v : save i ; color     i ; endfor ; enddef ;
 def newnumeric   text v = forsuffixes i=v : save i ; numeric   i ; endfor ; enddef ;
@@ -188,11 +188,11 @@ def pop_boundingbox text p =
 enddef;
 
 vardef boundingbox primary p =
-  if (path p) or (picture p) : 
-    llcorner p -- lrcorner p -- urcorner p -- ulcorner p 
-  else : 
-    origin 
-  fi -- cycle 
+  if (path p) or (picture p) :
+    llcorner p -- lrcorner p -- urcorner p -- ulcorner p
+  else :
+    origin
+  fi -- cycle
 enddef;
 
 vardef inner_boundingbox primary p =
@@ -238,10 +238,10 @@ vardef acos primary x = (asin(-x))                            enddef ;
 vardef atan primary x = (x-(x**3)/3+(x**5)/5-(x**7)/7)        enddef ;
 vardef tand primary x = (sind(x)/cosd(x))                     enddef ;
 
-%D Here are Taco Hoekwater's alternatives (but 
-%D vardef'd and primaried). 
+%D Here are Taco Hoekwater's alternatives (but
+%D vardef'd and primaried).
 
-pi := 3.1415926 ; radian := 180/pi ; % 2pi*radian = 360 ; 
+pi := 3.1415926 ; radian := 180/pi ; % 2pi*radian = 360 ;
 
 vardef tand   primary x = (sind(x)/cosd(x))  enddef ;
 vardef cotd   primary x = (cosd(x)/sind(x))  enddef ;
@@ -257,8 +257,8 @@ vardef acos   primary x = angle((x,1+-+x))   enddef ;
 vardef invsin primary x = ((asin(x))/radian) enddef ;
 vardef invcos primary x = ((acos(x))/radian) enddef ;
 
-vardef acosh  primary x = ln(x+(x+-+1))      enddef ; 
-vardef asinh  primary x = ln(x+(x++1))       enddef ; 
+vardef acosh  primary x = ln(x+(x+-+1))      enddef ;
+vardef asinh  primary x = ln(x+(x++1))       enddef ;
 
 vardef sinh   primary x = save xx ; xx = exp x ; (xx-1/xx)/2 enddef ;
 vardef cosh   primary x = save xx ; xx = exp x ; (xx+1/xx)/2 enddef ;
@@ -380,12 +380,12 @@ enddef;
 %   natural_width  := xpart urcorner currentpicture - xpart llcorner currentpicture;
 %   currentpicture := currentpicture scaled (the_width/natural_width) ;
 % enddef;
-% 
+%
 % def yscale_currentpicture(expr the_height ) =
 %   natural_height := ypart urcorner currentpicture - ypart llcorner currentpicture;
 %   currentpicture := currentpicture scaled (the_height/natural_height) ;
 % enddef;
-% 
+%
 % def xyscale_currentpicture(expr the_width, the_height) =
 %   natural_width  := xpart urcorner currentpicture - xpart llcorner currentpicture;
 %   natural_height := ypart urcorner currentpicture - ypart llcorner currentpicture;
@@ -393,40 +393,40 @@ enddef;
 %     xscaled (the_width/natural_width)
 %     yscaled (the_height/natural_height) ;
 % enddef;
-% 
+%
 % def scale_currentpicture(expr the_width, the_height) =
 %   xscale_currentpicture(the_width) ;
 %   yscale_currentpicture(the_height) ;
 % enddef;
 
-% nog eens uitbreiden zodat path en pic worden afgehandeld. 
+% nog eens uitbreiden zodat path en pic worden afgehandeld.
 
 %   natural_width  := xpart urcorner currentpicture - xpart llcorner currentpicture;
 %   currentpicture := currentpicture scaled (the_width/natural_width) ;
 
-% TODO TODO TODO TODO, not yet ok 
+% TODO TODO TODO TODO, not yet ok
 
 primarydef p xsized w =
-  (p if (bbwidth (p)>0) and (w>0) : scaled (w/bbwidth (p)) fi) 
+  (p if (bbwidth (p)>0) and (w>0) : scaled (w/bbwidth (p)) fi)
 enddef ;
 
 primarydef p ysized h =
-  (p if (bbheight(p)>0) and (h>0) : scaled (h/bbheight(p)) fi)  
+  (p if (bbheight(p)>0) and (h>0) : scaled (h/bbheight(p)) fi)
 enddef ;
 
 primarydef p xysized s =
-  begingroup ; 
-    save wh, w, h ; pair wh ; numeric w, h ; 
-    wh := paired (s) ; w := bbwidth(p) ; h := bbheight(p) ; 
-    (p if (w>0) and (h>0) : 
-         if xpart wh > 0 : xscaled (xpart wh/w) fi 
-         if ypart wh > 0 : yscaled (ypart wh/h) fi 
-       fi) 
-  endgroup 
+  begingroup ;
+    save wh, w, h ; pair wh ; numeric w, h ;
+    wh := paired (s) ; w := bbwidth(p) ; h := bbheight(p) ;
+    (p if (w>0) and (h>0) :
+         if xpart wh > 0 : xscaled (xpart wh/w) fi
+         if ypart wh > 0 : yscaled (ypart wh/h) fi
+       fi)
+  endgroup
 enddef ;
 
 primarydef p sized wh =
-  (p xysized wh) 
+  (p xysized wh)
 enddef ;
 
 def xscale_currentpicture(expr w) =
@@ -485,20 +485,20 @@ fulldiamond := unitdiamond shifted - center unitdiamond ;
 
 %D More robust:
 
-% let  normalscaled =  scaled ; 
-% let normalxscaled = xscaled ; 
-% let normalyscaled = yscaled ; 
-% 
-% def  scaled expr s =  normalscaled (s) enddef ; 
-% def xscaled expr s = normalxscaled (s) enddef ; 
-% def yscaled expr s = normalyscaled (s) enddef ; 
+% let  normalscaled =  scaled ;
+% let normalxscaled = xscaled ;
+% let normalyscaled = yscaled ;
+%
+% def  scaled expr s =  normalscaled (s) enddef ;
+% def xscaled expr s = normalxscaled (s) enddef ;
+% def yscaled expr s = normalyscaled (s) enddef ;
 
 %D Shorter
 
 primarydef p xyscaled q =
-  begingroup ; save qq ; pair qq ; qq = paired(q) ; 
-    ( p 
-      if xpart qq<>0 : xscaled (xpart qq) fi  
+  begingroup ; save qq ; pair qq ; qq = paired(q) ;
+    ( p
+      if xpart qq<>0 : xscaled (xpart qq) fi
       if ypart qq<>0 : yscaled (ypart qq) fi )
   endgroup
 enddef ;
@@ -605,7 +605,7 @@ vardef roundedsquare (expr width, height, offset) =
   ((offset,0)--(width-offset,0){right}          ..
    (width,offset)--(width,height-offset){up}    ..
    (width-offset,height)--(offset,height){left} ..
-   (0,height-offset)--(0,offset){down}          .. cycle)  
+   (0,height-offset)--(0,offset){down}          .. cycle)
 enddef ;
 
 %D Some colors.
@@ -622,7 +622,7 @@ def drawfill text t =
 enddef;
 
 %D This two step approach saves the path first, since it can
-%D be a function. Attributes must not be randomized. 
+%D be a function. Attributes must not be randomized.
 
 def drawfill expr c =
   path _c_ ; _c_ := c ;
@@ -684,47 +684,56 @@ primarydef p ulmoved d =
   ((ulcorner p) shifted (-xpart paired(d),+ypart paired(d)))
 enddef ;
 
-primarydef p leftenlarged d = 
-  ((llcorner p) shifted (-d,0) -- lrcorner p -- 
+primarydef p leftenlarged d =
+  ((llcorner p) shifted (-d,0) -- lrcorner p --
    urcorner p -- (ulcorner p) shifted (-d,0) -- cycle)
-enddef ; 
+enddef ;
+
+primarydef p rightenlarged d =
+  (llcorner p -- (lrcorner p) shifted (d,0) --
+   (urcorner p) shifted (d,0) -- ulcorner p -- cycle)
+enddef ;
 
-primarydef p rightenlarged d = 
-  (llcorner p -- (lrcorner p) shifted (d,0) -- 
-   (urcorner p) shifted (d,0) -- ulcorner p -- cycle) 
-enddef ; 
+primarydef p topenlarged d =
+  (llcorner p -- lrcorner p --
+   (urcorner p) shifted (0,d) -- (ulcorner p) shifted (0,d) -- cycle)
+enddef ;
+
+primarydef p bottomenlarged d =
+  (llcorner p shifted (0,-d) -- lrcorner p shifted (0,-d) --
+   urcorner p -- ulcorner p -- cycle)
+enddef ;
 
-primarydef p topenlarged d = 
-  (llcorner p -- lrcorner p -- 
-   (urcorner p) shifted (0,d) -- (ulcorner p) shifted (0,d) -- cycle) 
-enddef ; 
+%D Handy for testing/debugging:
 
-primarydef p bottomenlarged d = 
-  (llcorner p shifted (0,-d) -- lrcorner p shifted (0,-d) -- 
-   urcorner p -- ulcorner p -- cycle) 
-enddef ; 
+primarydef p crossed d =
+  (center p shifted (-d, 0) -- llcorner p --
+   center p shifted ( 0,-d) -- lrcorner p --
+   center p shifted (+d, 0) -- urcorner p --
+   center p shifted ( 0,+d) -- ulcorner p -- cycle)
+enddef ;
 
-%D Saves typing: 
+%D Saves typing:
 
 % vardef bottomboundary primary p = (llcorner p -- lrcorner p) enddef ;
 % vardef rightboundary  primary p = (lrcorner p -- urcorner p) enddef ;
 % vardef topboundary    primary p = (urcorner p -- ulcorner p) enddef ;
 % vardef leftboundary   primary p = (ulcorner p -- llcorner p) enddef ;
 
-vardef bottomboundary primary p = 
-  if pair p : p else : (llcorner p -- lrcorner p) fi 
+vardef bottomboundary primary p =
+  if pair p : p else : (llcorner p -- lrcorner p) fi
 enddef ;
 
-vardef rightboundary  primary p = 
-  if pair p : p else : (lrcorner p -- urcorner p) fi 
+vardef rightboundary  primary p =
+  if pair p : p else : (lrcorner p -- urcorner p) fi
 enddef ;
 
-vardef topboundary    primary p = 
-  if pair p : p else : (urcorner p -- ulcorner p) fi 
+vardef topboundary    primary p =
+  if pair p : p else : (urcorner p -- ulcorner p) fi
 enddef ;
 
-vardef leftboundary   primary p = 
-  if pair p : p else : (ulcorner p -- llcorner p) fi 
+vardef leftboundary   primary p =
+  if pair p : p else : (ulcorner p -- llcorner p) fi
 enddef ;
 
 %D Nice too:
@@ -742,158 +751,158 @@ primarydef p squeezed s =
   ((llcorner p .. .5[llcorner p,lrcorner p] shifted ( 0, ypart paired(s)) .. lrcorner p) &
    (lrcorner p .. .5[lrcorner p,urcorner p] shifted (-xpart paired(s), 0) .. urcorner p) &
    (urcorner p .. .5[urcorner p,ulcorner p] shifted ( 0,-ypart paired(s)) .. ulcorner p) &
-   (ulcorner p .. .5[ulcorner p,llcorner p] shifted ( xpart paired(s), 0) .. llcorner p) & cycle) 
+   (ulcorner p .. .5[ulcorner p,llcorner p] shifted ( xpart paired(s), 0) .. llcorner p) & cycle)
 enddef ;
 
-primarydef p randomshifted s = 
-  begingroup ; save ss ; pair ss ; ss := paired(s) ; 
+primarydef p randomshifted s =
+  begingroup ; save ss ; pair ss ; ss := paired(s) ;
   p shifted (-.5xpart ss + uniformdeviate xpart ss,
-             -.5ypart ss + uniformdeviate ypart ss) 
-  endgroup 
-enddef ; 
+             -.5ypart ss + uniformdeviate ypart ss)
+  endgroup
+enddef ;
 
 %primarydef p randomized s =
-%  for i=0 upto length(p)-1 : 
-%   ((point       i    of p) randomshifted s) .. controls 
-%   ((postcontrol i    of p) randomshifted s) and 
-%   ((precontrol (i+1) of p) randomshifted s) .. 
-%  endfor cycle 
+%  for i=0 upto length(p)-1 :
+%   ((point       i    of p) randomshifted s) .. controls
+%   ((postcontrol i    of p) randomshifted s) and
+%   ((precontrol (i+1) of p) randomshifted s) ..
+%  endfor cycle
 %enddef ;
 
 primarydef p randomized s =
-  (if path p : 
+  (if path p :
     for i=0 upto length(p)-1 :
-      ((point       i    of p) randomshifted s) .. controls 
-      ((postcontrol i    of p) randomshifted s) and 
-      ((precontrol (i+1) of p) randomshifted s) .. 
-    endfor 
-    if cycle p : 
-      cycle 
+      ((point       i    of p) randomshifted s) .. controls
+      ((postcontrol i    of p) randomshifted s) and
+      ((precontrol (i+1) of p) randomshifted s) ..
+    endfor
+    if cycle p :
+      cycle
     else :
-      ((point length(p) of p) randomshifted s) 
+      ((point length(p) of p) randomshifted s)
     fi
   elseif pair p :
-    p randomshifted s  
+    p randomshifted s
   elseif color p :
-    if color s : 
+    if color s :
       (uniformdeviate redpart   s * redpart   p,
        uniformdeviate greenpart s * greenpart p,
-       uniformdeviate bluepart  s * bluepart  p)  
-    elseif pair s : 
-      ((xpart s + uniformdeviate (ypart s - xpart s)) * p)  
-    else :  
-      (uniformdeviate s * p)  
-    fi 
+       uniformdeviate bluepart  s * bluepart  p)
+    elseif pair s :
+      ((xpart s + uniformdeviate (ypart s - xpart s)) * p)
+    else :
+      (uniformdeviate s * p)
+    fi
   else :
-    p + uniformdeviate s  
-  fi)  
-enddef ; 
+    p + uniformdeviate s
+  fi)
+enddef ;
 
-%D Not perfect (alternative for interpath) 
+%D Not perfect (alternative for interpath)
 
 vardef interpolated(expr s, p, q) =
-  save m ; m := max(length(p),length(q)) ; 
-  (if path p : 
+  save m ; m := max(length(p),length(q)) ;
+  (if path p :
      for i=0 upto m-1 :
        s[point       (i   /m) along p,
-         point       (i   /m) along q] .. controls 
+         point       (i   /m) along q] .. controls
        s[postcontrol (i   /m) along p,
-         postcontrol (i   /m) along q] and 
+         postcontrol (i   /m) along q] and
        s[precontrol ((i+1)/m) along p,
-         precontrol ((i+1)/m) along q] .. 
-     endfor 
-     if cycle p : 
-       cycle 
+         precontrol ((i+1)/m) along q] ..
+     endfor
+     if cycle p :
+       cycle
      else :
        s[point infinity of p,
-         point infinity of q] 
+         point infinity of q]
      fi
    else :
      a[p,q]
-   fi)  
-enddef ; 
+   fi)
+enddef ;
 
 %D Interesting too:
 
 % primarydef p parallel s =
-%   begingroup ; save q, b ; path q ; numeric b ; 
-%   b := xpart (lrcorner p - llcorner p) ; 
+%   begingroup ; save q, b ; path q ; numeric b ;
+%   b := xpart (lrcorner p - llcorner p) ;
 %   q := p if b>0 : scaled ((b+2s)/b) fi ;
-%   (q shifted (center p-center q)) 
-%   endgroup 
-% enddef ; 
+%   (q shifted (center p-center q))
+%   endgroup
+% enddef ;
 
 %primarydef p parallel s =
-%  begingroup ; save q, w,h ; path q ; numeric w, h ; 
-%  w := bbwidth(p) ; h := bbheight(p) ; 
-%  q := p if (w>0) and (h>0) : 
+%  begingroup ; save q, w,h ; path q ; numeric w, h ;
+%  w := bbwidth(p) ; h := bbheight(p) ;
+%  q := p if (w>0) and (h>0) :
 %    xyscaled ((w+2*xpart paired(s))/w,(h+2*ypart paired(s))/h) fi ;
-%  (q shifted (center p-center q)) 
-%  endgroup 
-%enddef ; 
-
-vardef punked primary p = 
-  (point 0 of p for i=1 upto length(p)-1 : -- point i of p endfor 
-   if cycle p : -- cycle else : -- point length(p) of p fi)  
-enddef ;  
-
-vardef curved primary p = 
-  (point 0 of p for i=1 upto length(p)-1 : .. point i of p endfor 
-   if cycle p : .. cycle else : .. point length(p) of p fi)  
-enddef ;  
-
-primarydef p blownup s = 
-  begingroup 
-    save _p_ ; path _p_ ; _p_ := p xysized 
+%  (q shifted (center p-center q))
+%  endgroup
+%enddef ;
+
+vardef punked primary p =
+  (point 0 of p for i=1 upto length(p)-1 : -- point i of p endfor
+   if cycle p : -- cycle else : -- point length(p) of p fi)
+enddef ;
+
+vardef curved primary p =
+  (point 0 of p for i=1 upto length(p)-1 : .. point i of p endfor
+   if cycle p : .. cycle else : .. point length(p) of p fi)
+enddef ;
+
+primarydef p blownup s =
+  begingroup
+    save _p_ ; path _p_ ; _p_ := p xysized
      (bbwidth (p)+2(xpart paired(s)),
-      bbheight(p)+2(ypart paired(s))) ; 
+      bbheight(p)+2(ypart paired(s))) ;
     (_p_ shifted (center p - center _p_))
-  endgroup 
+  endgroup
 enddef ;
 
-%D Rather fundamental. 
+%D Rather fundamental.
 
-% vardef rightpath expr p = 
-%   save q, t, b ; path q ; pair t, b ;  
-%   t := (ulcorner p -- urcorner p) intersection_point p ; 
-%   b := (llcorner p -- lrcorner p) intersection_point p ; 
+% vardef rightpath expr p =
+%   save q, t, b ; path q ; pair t, b ;
+%   t := (ulcorner p -- urcorner p) intersection_point p ;
+%   b := (llcorner p -- lrcorner p) intersection_point p ;
 %   if xpart directionpoint t of p < 0 : p := reverse p ; fi ;
 %   q := p cutbefore b ;
 %   q := q if xpart point 0 of p > 0 : & p fi cutafter t ;
-%   q 
-% enddef ; 
-% 
-% vardef leftpath expr p = 
-%   save q, t, b ; path q ; pair t, b ;  
-%   t := (ulcorner p -- urcorner p) intersection_point p ; 
-%   b := (llcorner p -- lrcorner p) intersection_point p ; 
+%   q
+% enddef ;
+%
+% vardef leftpath expr p =
+%   save q, t, b ; path q ; pair t, b ;
+%   t := (ulcorner p -- urcorner p) intersection_point p ;
+%   b := (llcorner p -- lrcorner p) intersection_point p ;
 %   if xpart directionpoint t of p < 0 : p := reverse p ; fi ;
 %   q := p cutbefore t ;
 %   q := q if xpart point 0 of p > 0 : & p fi cutafter b ;
-%   q 
-% enddef ; 
+%   q
+% enddef ;
 
-def leftrightpath(expr p, l) = 
-  save q, t, b ; path q ; pair t, b ;  
-  t := (ulcorner p -- urcorner p) intersection_point p ; 
-  b := (llcorner p -- lrcorner p) intersection_point p ; 
+def leftrightpath(expr p, l) =
+  save q, t, b ; path q ; pair t, b ;
+  t := (ulcorner p -- urcorner p) intersection_point p ;
+  b := (llcorner p -- lrcorner p) intersection_point p ;
   if xpart directionpoint t of p < 0 : p := reverse p ; fi ;
   q := p    cutbefore if l: t else: b fi ;
-  q := q if xpart point 0 of p > 0 : & 
+  q := q if xpart point 0 of p > 0 : &
        p fi cutafter  if l: b else: t fi ;
-  q 
-enddef ; 
+  q
+enddef ;
 
-vardef  leftpath expr p = leftrightpath(p,true ) enddef ; 
-vardef rightpath expr p = leftrightpath(p,false) enddef ; 
+vardef  leftpath expr p = leftrightpath(p,true ) enddef ;
+vardef rightpath expr p = leftrightpath(p,false) enddef ;
 
-%D Drawoptions 
+%D Drawoptions
 
 def saveoptions =
-  save _op_ ; def _op_ = enddef ; 
-enddef ; 
- 
-%D Tracing. 
+  save _op_ ; def _op_ = enddef ;
+enddef ;
+
+%D Tracing.
 
 let normaldraw = draw ;
 let normalfill = fill ;
@@ -906,7 +915,7 @@ def draworiginoptions (text t) = def _ori_opt_ = t enddef ; enddef ;
 def drawboundoptions  (text t) = def _bnd_opt_ = t enddef ; enddef ;
 def drawpathoptions   (text t) = def _pth_opt_ = t enddef ; enddef ;
 
-def resetdrawoptions = 
+def resetdrawoptions =
   drawlineoptions   (withpen pencircle scaled 1pt   withcolor .5white) ;
   drawpointoptions  (withpen pencircle scaled 4pt   withcolor   black) ;
   drawcontroloptions(withpen pencircle scaled 2.5pt withcolor   black) ;
@@ -914,7 +923,7 @@ def resetdrawoptions =
   draworiginoptions (withpen pencircle scaled 1pt   withcolor .5white) ;
   drawboundoptions  (dashed evenly _ori_opt_) ;
   drawpathoptions   (withpen pencircle scaled 5pt   withcolor .8white) ;
-enddef ; 
+enddef ;
 
 resetdrawoptions ;
 
@@ -926,47 +935,47 @@ enddef ;
 
 %D Arrow.
 
-vardef drawarrowpath expr p = 
-  save autoarrows ; boolean autoarrows ; autoarrows := true ; 
-  drawarrow p _pth_opt_ 
-enddef ; 
-
-%def drawarrowpath expr p = 
-%  begingroup ; 
-%  save autoarrows ; boolean autoarrows ; autoarrows := true ; 
-%  save arrowpath ; path arrowpath ; arrowpath := p ; 
-%  _drawarrowpath_ 
-%enddef ; 
+vardef drawarrowpath expr p =
+  save autoarrows ; boolean autoarrows ; autoarrows := true ;
+  drawarrow p _pth_opt_
+enddef ;
+
+%def drawarrowpath expr p =
+%  begingroup ;
+%  save autoarrows ; boolean autoarrows ; autoarrows := true ;
+%  save arrowpath ; path arrowpath ; arrowpath := p ;
+%  _drawarrowpath_
+%enddef ;
 %
-%def _drawarrowpath_ text t = 
-%  drawarrow arrowpath _pth_opt_ t ; 
-%  endgroup ; 
-%enddef ;  
+%def _drawarrowpath_ text t =
+%  drawarrow arrowpath _pth_opt_ t ;
+%  endgroup ;
+%enddef ;
 
 def midarrowhead expr p =
-  arrowhead p cutafter 
-    (point length(p cutafter point .5 along p)+ahlength on p) 
-enddef ; 
+  arrowhead p cutafter
+    (point length(p cutafter point .5 along p)+ahlength on p)
+enddef ;
 
 vardef arrowheadonpath (expr p, s) =
   save autoarrows ; boolean autoarrows ; autoarrows := true ;
   arrowhead p if s<1 : cutafter (point (s*arclength(p)+.5ahlength) on p) fi
 enddef ;
- 
+
 %D Points.
 
-def drawpoint expr c = 
-  if string c : 
-    string _c_ ; _c_ := "(" & c & ")" ; 
-    dotlabel.urt(_c_, scantokens _c_) ; 
-    drawdot scantokens _c_ 
-  else : 
-    dotlabel.urt("(" & decimal xpart c & "," & decimal ypart c & ")", c) ; 
-    drawdot c 
-  fi _pnt_opt_ 
-enddef ; 
+def drawpoint expr c =
+  if string c :
+    string _c_ ; _c_ := "(" & c & ")" ;
+    dotlabel.urt(_c_, scantokens _c_) ;
+    drawdot scantokens _c_
+  else :
+    dotlabel.urt("(" & decimal xpart c & "," & decimal ypart c & ")", c) ;
+    drawdot c
+  fi _pnt_opt_
+enddef ;
 
-%D PathPoints. 
+%D PathPoints.
 
 def drawpoints        expr c = path _c_ ; _c_ := c ; do_drawpoints        enddef ;
 def drawcontrolpoints expr c = path _c_ ; _c_ := c ; do_drawcontrolpoints enddef ;
@@ -993,37 +1002,37 @@ def do_drawcontrollines text t =
   endfor ;
 enddef;
 
-boolean swappointlabels ; swappointlabels := false ; 
+boolean swappointlabels ; swappointlabels := false ;
 
 def do_drawpointlabels text t =
   for _i_=0 upto length(_c_) :
-    pair _u_ ; _u_ := unitvector(direction _i_ of _c_) 
+    pair _u_ ; _u_ := unitvector(direction _i_ of _c_)
       rotated if swappointlabels : - fi 90 ;
     pair _p_ ; _p_ := (point _i_ of _c_) ;
     _u_ := 12 * defaultscale * _u_ ;
-    normaldraw thelabel ( decimal _i_, 
+    normaldraw thelabel ( decimal _i_,
     _p_ shifted if cycle _c_ and (_i_=0) : - fi _u_ ) _lab_opt_ t ;
   endfor ;
 enddef;
 
-%D Bounding box. 
+%D Bounding box.
 
 def drawboundingbox expr p =
   normaldraw boundingbox p _bnd_opt_
 enddef ;
 
-%D Origin. 
+%D Origin.
 
 numeric originlength ; originlength := .5cm ;
 
 def draworigin text t =
   normaldraw (origin shifted (0, originlength) --
               origin shifted (0,-originlength)) _ori_opt_ t ;
-  normaldraw (origin shifted ( originlength,0) -- 
+  normaldraw (origin shifted ( originlength,0) --
               origin shifted (-originlength,0)) _ori_opt_ t ;
 enddef;
 
-%D Axis. 
+%D Axis.
 
 numeric tickstep   ; tickstep   := 5mm ;
 numeric ticklength ; ticklength := 2mm ;
@@ -1032,9 +1041,9 @@ def drawxticks expr c = path _c_ ; _c_ := c ; do_drawxticks enddef ;
 def drawyticks expr c = path _c_ ; _c_ := c ; do_drawyticks enddef ;
 def drawticks  expr c = path _c_ ; _c_ := c ; do_drawticks  enddef ;
 
-% Adding eps prevents disappearance due to rounding errors. 
+% Adding eps prevents disappearance due to rounding errors.
 
-def do_drawxticks text t = 
+def do_drawxticks text t =
   for i=0 step -tickstep until xpart llcorner _c_ - eps :
     if (i<=xpart lrcorner _c_) :
       normaldraw (i,-ticklength)--(i,ticklength) _ori_opt_ t ;
@@ -1081,14 +1090,14 @@ def drawwholepath expr p =
   drawpointlabels   p ;
 enddef ;
 
-%D Tracing. 
+%D Tracing.
 
-def visualizeddraw expr c = 
-  if picture c : normaldraw c else : path _c_ ; _c_ := c ; do_visualizeddraw fi 
+def visualizeddraw expr c =
+  if picture c : normaldraw c else : path _c_ ; _c_ := c ; do_visualizeddraw fi
 enddef ;
 
-def visualizedfill expr c = 
-  if picture c : normalfill c else : path _c_ ; _c_ := c ; do_visualizedfill fi 
+def visualizedfill expr c =
+  if picture c : normalfill c else : path _c_ ; _c_ := c ; do_visualizedfill fi
 enddef ;
 
 def do_visualizeddraw text t =
@@ -1103,7 +1112,7 @@ enddef ;
 
 def do_visualizedfill text t =
   if cycle _c_ : normalfill _c_ t fi ;
-  draworigin            ; 
+  draworigin            ;
   drawcontrollines  _c_ ;
   drawcontrolpoints _c_ ;
   drawpoints        _c_ ;
@@ -1123,121 +1132,121 @@ enddef ;
 
 extra_endfig := extra_endfig & " naturalizepaths ; " ;
 
-%D Normally, arrowheads don't scale well. So we provide a 
-%D hack. 
+%D Normally, arrowheads don't scale well. So we provide a
+%D hack.
 
-boolean autoarrows ; autoarrows := false ; 
-numeric ahfactor   ; ahfactor   := 2.5 ; 
+boolean autoarrows ; autoarrows := false ;
+numeric ahfactor   ; ahfactor   := 2.5 ;
 
-def set_ahlength (text t) = 
+def set_ahlength (text t) =
   ahlength := (ahfactor*pen_size(_op_ t)) ; % _op_ added
-enddef ; 
+enddef ;
 
-vardef pen_size (text t) = 
-  save p ; picture p ; p := nullpicture ; 
-  addto p doublepath (top origin -- bot origin) t ; 
-  (ypart urcorner p - ypart lrcorner p) 
-enddef ; 
+vardef pen_size (text t) =
+  save p ; picture p ; p := nullpicture ;
+  addto p doublepath (top origin -- bot origin) t ;
+  (ypart urcorner p - ypart lrcorner p)
+enddef ;
 
-%D The next two macros are adapted versions of plain 
-%D \METAPOST\ definitions. 
+%D The next two macros are adapted versions of plain
+%D \METAPOST\ definitions.
 
 def _finarr text t =
-  if autoarrows : set_ahlength (t) fi ;  
+  if autoarrows : set_ahlength (t) fi ;
   draw               _apth t ;
   filldraw arrowhead _apth t ;
 enddef;
 
 def _findarr text t =
-  if autoarrows : set_ahlength (t) fi ;  
+  if autoarrows : set_ahlength (t) fi ;
   draw                   _apth                    t ;
   fill arrowhead         _apth withpen currentpen t ;
   fill arrowhead reverse _apth withpen currentpen t ;
 enddef ;
 
-%D Handy too ...... 
+%D Handy too ......
 
 vardef pointarrow (expr pat, loc, len, off) =
-  save l, r, s, t ; path l, r ; numeric s ; pair t ;  
-  t := if pair loc : loc else : point loc along pat fi ; 
-% draw t withpen pencircle scaled 10 withcolor .5white ; 
-  s := len/2 - off ; if s<=0 : s := 0 elseif s>len : s := len fi ;  
+  save l, r, s, t ; path l, r ; numeric s ; pair t ;
+  t := if pair loc : loc else : point loc along pat fi ;
+% draw t withpen pencircle scaled 10 withcolor .5white ;
+  s := len/2 - off ; if s<=0 : s := 0 elseif s>len : s := len fi ;
   r := pat cutbefore t ;
   r := (r cutafter point (arctime s of r) of r) ;
-  s := len/2 + off ; if s<=0 : s := 0 elseif s>len : s := len fi ;  
+  s := len/2 + off ; if s<=0 : s := 0 elseif s>len : s := len fi ;
   l := reverse (pat cutafter t) ;
   l := (reverse (l cutafter point (arctime s of l) of l)) ;
-  (l..r) 
-enddef ; 
+  (l..r)
+enddef ;
 
-def rightarrow  (expr pat,tim,len) = pointarrow(pat,tim,len,-len) enddef ; 
-def leftarrow   (expr pat,tim,len) = pointarrow(pat,tim,len,+len) enddef ; 
+def rightarrow  (expr pat,tim,len) = pointarrow(pat,tim,len,-len) enddef ;
+def leftarrow   (expr pat,tim,len) = pointarrow(pat,tim,len,+len) enddef ;
 def centerarrow (expr pat,tim,len) = pointarrow(pat,tim,len,   0) enddef ;
 
-%D The \type {along} and \type {on} operators can be used 
-%D as follows: 
+%D The \type {along} and \type {on} operators can be used
+%D as follows:
 %D
 %D \starttypen
-%D drawdot point .5  along somepath ; 
-%D drawdot point 3cm on    somepath ; 
+%D drawdot point .5  along somepath ;
+%D drawdot point 3cm on    somepath ;
 %D \stoptypen
-%D 
-%D The number denotes a percentage (fraction). 
+%D
+%D The number denotes a percentage (fraction).
 
-primarydef pct along pat = % also negative 
-  (arctime (pct * (arclength pat)) of pat) of pat  
-enddef ;   
+primarydef pct along pat = % also negative
+  (arctime (pct * (arclength pat)) of pat) of pat
+enddef ;
 
 % primarydef len on pat =
 %   (arctime len of pat) of pat
-% enddef ;   
+% enddef ;
 
 primarydef len on pat =
-  (arctime if len>0 : len else : (arclength(pat)+len) fi of pat) of pat 
-enddef ;   
+  (arctime if len>0 : len else : (arclength(pat)+len) fi of pat) of pat
+enddef ;
 
-% this cuts of a piece from both ends 
+% this cuts of a piece from both ends
 
 % tertiarydef pat cutends len =
-%   begingroup ; save tap ; path tap ; 
-%   tap := pat cutbefore (point len on pat) ; 
-%   (tap cutafter (point -len on tap))  
-%   endgroup 
-% enddef ;   
+%   begingroup ; save tap ; path tap ;
+%   tap := pat cutbefore (point len on pat) ;
+%   (tap cutafter (point -len on tap))
+%   endgroup
+% enddef ;
 
 tertiarydef pat cutends len =
-  begingroup ; save tap ; path tap ; 
-  tap := pat cutbefore (point (xpart paired(len)) on pat) ; 
-  (tap cutafter (point -(ypart paired(len)) on tap))  
-  endgroup 
-enddef ;   
+  begingroup ; save tap ; path tap ;
+  tap := pat cutbefore (point (xpart paired(len)) on pat) ;
+  (tap cutafter (point -(ypart paired(len)) on tap))
+  endgroup
+enddef ;
 
-%D To be documented. 
+%D To be documented.
 
-path freesquare ; 
+path freesquare ;
 
 freesquare := ((-1,0)--(-1,-1)--(0,-1)--(+1,-1)--
                (+1,0)--(+1,+1)--(0,+1)--(-1,+1)--cycle) scaled .5 ;
 
-numeric freelabeloffset  ; freelabeloffset  := 3pt ; 
-numeric freedotlabelsize ; freedotlabelsize := 3pt ; 
+numeric freelabeloffset  ; freelabeloffset  := 3pt ;
+numeric freedotlabelsize ; freedotlabelsize := 3pt ;
 
-vardef thefreelabel (expr str, loc, ori) = 
-  save s, p, q, l ; picture s ; path p, q ; pair l ; 
-  interim labeloffset := freelabeloffset ; 
+vardef thefreelabel (expr str, loc, ori) =
+  save s, p, q, l ; picture s ; path p, q ; pair l ;
+  interim labeloffset := freelabeloffset ;
   s := if string str : thelabel(str,loc) else : str shifted -center str shifted loc fi ;
-  setbounds s to boundingbox s enlarged freelabeloffset ; 
+  setbounds s to boundingbox s enlarged freelabeloffset ;
   p := fullcircle scaled (2*length(loc-ori)) shifted ori ;
   q := freesquare xyscaled (urcorner s - llcorner s) ;
 %  l := point (xpart (p intersectiontimes (ori--loc))) of q ;
-  l := point xpart (p intersectiontimes 
+  l := point xpart (p intersectiontimes
    (ori--((1+eps)*arclength(ori--loc)*unitvector(loc-ori)))) of q ;
-  setbounds s to boundingbox s enlarged -freelabeloffset ; % new  
- %draw boundingbox s shifted -l withpen pencircle scaled .5pt withcolor red ; 
-  (s shifted -l) 
-enddef ; 
+  setbounds s to boundingbox s enlarged -freelabeloffset ; % new
+ %draw boundingbox s shifted -l withpen pencircle scaled .5pt withcolor red ;
+  (s shifted -l)
+enddef ;
 
-% better? 
+% better?
 
 vardef thefreelabel (expr str, loc, ori) =
   save s, p, q, l ; picture s ; path p, q ; pair l ;
@@ -1252,15 +1261,15 @@ vardef thefreelabel (expr str, loc, ori) =
   (s shifted -l)
 enddef ;
 
-vardef freelabel (expr str, loc, ori) = 
+vardef freelabel (expr str, loc, ori) =
   draw thefreelabel(str,loc,ori) ;
-enddef ; 
+enddef ;
 
-vardef freedotlabel (expr str, loc, ori) = 
+vardef freedotlabel (expr str, loc, ori) =
   interim linecap:=rounded ;
   draw loc withpen pencircle scaled freedotlabelsize ;
   draw thefreelabel(str,loc,ori) ;
-enddef ; 
+enddef ;
 
 %D \starttypen
 %D drawarrow anglebetween(line_a,line_b,somelabel) ;
@@ -1270,38 +1279,38 @@ enddef ;
 numeric anglelength ; anglelength := 20pt ;
 numeric anglemethod ; anglemethod :=    1 ;
 
-% vardef anglebetween (expr a, b, str) = % path path string 
+% vardef anglebetween (expr a, b, str) = % path path string
 %   save pointa, pointb, common, middle, offset ;
 %   pair pointa, pointb, common, middle, offset ;
-%   save curve ; path curve ; 
-%   save where ; numeric where ; 
-%   if round point 0 of a = round point 0 of b : 
+%   save curve ; path curve ;
+%   save where ; numeric where ;
+%   if round point 0 of a = round point 0 of b :
 %     common := point 0 of a ;
 %   else :
 %     common := a intersectionpoint b ;
-%   fi ; 
-%   pointa := point anglelength on a ; 
-%   pointb := point anglelength on b ; 
-%   where  := turningnumber (common--pointa--pointb--cycle) ; 
+%   fi ;
+%   pointa := point anglelength on a ;
+%   pointb := point anglelength on b ;
+%   where  := turningnumber (common--pointa--pointb--cycle) ;
 %   middle := ((common--pointa) rotatedaround (pointa,-where*90))
-%                             intersectionpoint 
-%             ((common--pointb) rotatedaround (pointb, where*90)) ;  
+%                             intersectionpoint
+%             ((common--pointb) rotatedaround (pointb, where*90)) ;
 %   if     anglemethod = 0 :
-%     curve  := pointa{unitvector(middle-pointa)}.. pointb; 
-%     middle := point .5 along curve ; 
-%     curve  := common ;  
-%   elseif anglemethod = 1 :  
-%     curve  := pointa{unitvector(middle-pointa)}.. pointb; 
-%     middle := point .5 along curve ; 
-%   elseif anglemethod = 2 :  
-%     middle := common rotatedaround(.5[pointa,pointb],180) ; 
-%     curve  := pointa--middle--pointb ; 
-%   elseif anglemethod = 3 :    
-%     curve  := pointa--middle--pointb ; 
-%   elseif anglemethod = 4 :    
-%     curve  := pointa..controls middle..pointb ; 
-%     middle := point .5 along curve ; 
-%   fi ; 
+%     curve  := pointa{unitvector(middle-pointa)}.. pointb;
+%     middle := point .5 along curve ;
+%     curve  := common ;
+%   elseif anglemethod = 1 :
+%     curve  := pointa{unitvector(middle-pointa)}.. pointb;
+%     middle := point .5 along curve ;
+%   elseif anglemethod = 2 :
+%     middle := common rotatedaround(.5[pointa,pointb],180) ;
+%     curve  := pointa--middle--pointb ;
+%   elseif anglemethod = 3 :
+%     curve  := pointa--middle--pointb ;
+%   elseif anglemethod = 4 :
+%     curve  := pointa..controls middle..pointb ;
+%     middle := point .5 along curve ;
+%   fi ;
 %   draw thefreelabel(str, middle, common) withcolor black ;
 %   curve
 % enddef ;
@@ -1349,250 +1358,269 @@ enddef ;
 
 % Stack
 
-picture currentpicturestack[] ; 
-numeric currentpicturedepth ; currentpicturedepth := 0 ; 
+picture currentpicturestack[] ;
+numeric currentpicturedepth ; currentpicturedepth := 0 ;
 
-def pushcurrentpicture = 
-  currentpicturedepth := currentpicturedepth + 1 ; 
-  currentpicturestack[currentpicturedepth] := currentpicture ; 
-  currentpicture := nullpicture ; 
+def pushcurrentpicture =
+  currentpicturedepth := currentpicturedepth + 1 ;
+  currentpicturestack[currentpicturedepth] := currentpicture ;
+  currentpicture := nullpicture ;
 enddef ;
 
-def popcurrentpicture text t = % optional text 
-  if currentpicturedepth > 0 : 
+def popcurrentpicture text t = % optional text
+  if currentpicturedepth > 0 :
     addto currentpicturestack[currentpicturedepth] also currentpicture t ;
     currentpicture := currentpicturestack[currentpicturedepth] ;
-    currentpicturedepth := currentpicturedepth - 1 ; 
+    currentpicturedepth := currentpicturedepth - 1 ;
   fi ;
 enddef ;
 
-%D colorcircle(size, red, green, blue) ; 
+%D colorcircle(size, red, green, blue) ;
 
-% vardef colorcircle (expr size, red, green, blue) = 
+% vardef colorcircle (expr size, red, green, blue) =
 %   save r, g, b, rr, gg, bb, cc, mm, yy ; save radius ;
-%   path r, g, b, rr, bb, gg, cc, mm, yy ; numeric radius ; 
-% 
-%   radius := 5cm ; pickup pencircle scaled (radius/25) ; 
-% 
+%   path r, g, b, rr, bb, gg, cc, mm, yy ; numeric radius ;
+%
+%   radius := 5cm ; pickup pencircle scaled (radius/25) ;
+%
 %   r := g := b := fullcircle scaled radius shifted (0,radius/4) ;
-% 
-%   r := r rotatedaround (origin, 15) ; 
-%   g := g rotatedaround (origin,135) ; 
-%   b := b rotatedaround (origin,255) ; 
-% 
-%   r := r rotatedaround(center r,-90) ; 
-%   g := g rotatedaround(center g, 90) ; 
-% 
-%   gg := buildcycle(buildcycle(reverse r,b),g) ; 
-%   cc := buildcycle(buildcycle(b,reverse g),r) ; 
-% 
-%   rr := gg rotatedaround(origin,120) ; 
-%   bb := gg rotatedaround(origin,240) ; 
-% 
-%   yy := cc rotatedaround(origin,120) ; 
-%   mm := cc rotatedaround(origin,240) ; 
-% 
-%   pushcurrentpicture ; 
-% 
+%
+%   r := r rotatedaround (origin, 15) ;
+%   g := g rotatedaround (origin,135) ;
+%   b := b rotatedaround (origin,255) ;
+%
+%   r := r rotatedaround(center r,-90) ;
+%   g := g rotatedaround(center g, 90) ;
+%
+%   gg := buildcycle(buildcycle(reverse r,b),g) ;
+%   cc := buildcycle(buildcycle(b,reverse g),r) ;
+%
+%   rr := gg rotatedaround(origin,120) ;
+%   bb := gg rotatedaround(origin,240) ;
+%
+%   yy := cc rotatedaround(origin,120) ;
+%   mm := cc rotatedaround(origin,240) ;
+%
+%   pushcurrentpicture ;
+%
 %   fill fullcircle scaled radius withcolor white ;
-% 
-%   fill rr withcolor red   ; fill cc withcolor white-red   ; 
-%   fill gg withcolor green ; fill mm withcolor white-green ; 
-%   fill bb withcolor blue  ; fill yy withcolor white-blue  ; 
-% 
-%   for i = rr,gg,bb,cc,mm,yy : draw i withcolor .5white ; endfor ;   
-% 
-%   currentpicture := currentpicture xsized size ; 
-% 
+%
+%   fill rr withcolor red   ; fill cc withcolor white-red   ;
+%   fill gg withcolor green ; fill mm withcolor white-green ;
+%   fill bb withcolor blue  ; fill yy withcolor white-blue  ;
+%
+%   for i = rr,gg,bb,cc,mm,yy : draw i withcolor .5white ; endfor ;
+%
+%   currentpicture := currentpicture xsized size ;
+%
 %   popcurrentpicture ;
-% enddef ;   
+% enddef ;
 
-% vardef colorcircle (expr size, red, green, blue) = 
+% vardef colorcircle (expr size, red, green, blue) =
 %   save r, g, b, rr, gg, bb, cc, mm, yy ; save radius ;
-%   path r, g, b, rr, bb, gg, cc, mm, yy ; numeric radius ; 
-% 
-%   radius := 5cm ; pickup pencircle scaled (radius/25) ; 
-% 
-%   transform t ; t := identity rotatedaround(origin,120) ; 
-% 
-%   r := fullcircle scaled radius 
-%    shifted (0,radius/4) rotatedaround(origin,15) ; 
-% 
-%   g := r transformed t ; b := g transformed t ; 
-% 
-%   r := r rotatedaround(center r,-90) ; 
-%   g := g rotatedaround(center g, 90) ; 
-% 
-%   gg := buildcycle(buildcycle(reverse r,b),g) ; 
-%   cc := buildcycle(buildcycle(b,reverse g),r) ; 
-% 
-%   rr := gg transformed t ; bb := rr transformed t ; 
-%   yy := cc transformed t ; mm := yy transformed t ; 
-% 
-%   pushcurrentpicture ; 
-% 
+%   path r, g, b, rr, bb, gg, cc, mm, yy ; numeric radius ;
+%
+%   radius := 5cm ; pickup pencircle scaled (radius/25) ;
+%
+%   transform t ; t := identity rotatedaround(origin,120) ;
+%
+%   r := fullcircle scaled radius
+%    shifted (0,radius/4) rotatedaround(origin,15) ;
+%
+%   g := r transformed t ; b := g transformed t ;
+%
+%   r := r rotatedaround(center r,-90) ;
+%   g := g rotatedaround(center g, 90) ;
+%
+%   gg := buildcycle(buildcycle(reverse r,b),g) ;
+%   cc := buildcycle(buildcycle(b,reverse g),r) ;
+%
+%   rr := gg transformed t ; bb := rr transformed t ;
+%   yy := cc transformed t ; mm := yy transformed t ;
+%
+%   pushcurrentpicture ;
+%
 %   fill fullcircle scaled radius withcolor white ;
-% 
-%   fill rr withcolor red   ; fill cc withcolor white-red   ; 
-%   fill gg withcolor green ; fill mm withcolor white-green ; 
-%   fill bb withcolor blue  ; fill yy withcolor white-blue  ; 
-% 
-%   for i = rr,gg,bb,cc,mm,yy : draw i withcolor .5white ; endfor ;   
-% 
-%   currentpicture := currentpicture xsized size ; 
-% 
+%
+%   fill rr withcolor red   ; fill cc withcolor white-red   ;
+%   fill gg withcolor green ; fill mm withcolor white-green ;
+%   fill bb withcolor blue  ; fill yy withcolor white-blue  ;
+%
+%   for i = rr,gg,bb,cc,mm,yy : draw i withcolor .5white ; endfor ;
+%
+%   currentpicture := currentpicture xsized size ;
+%
 %   popcurrentpicture ;
-% enddef ;   
+% enddef ;
 
-vardef colorcircle (expr size, red, green, blue) = 
-  save r, g, b, c, m, y, w ; save radius ; 
-  path r, g, b, c, m, y, w ; numeric radius ; 
+vardef colorcircle (expr size, red, green, blue) =
+  save r, g, b, c, m, y, w ; save radius ;
+  path r, g, b, c, m, y, w ; numeric radius ;
 
-  radius := 5cm ; pickup pencircle scaled (radius/25) ; 
+  radius := 5cm ; pickup pencircle scaled (radius/25) ;
 
-  transform t ; t := identity rotatedaround(origin,120) ; 
+  transform t ; t := identity rotatedaround(origin,120) ;
 
-  r := fullcircle rotated 90 scaled radius 
-         shifted (0,radius/4) rotatedaround(origin,135) ; 
+  r := fullcircle rotated 90 scaled radius
+         shifted (0,radius/4) rotatedaround(origin,135) ;
 
-  b := r transformed t ; g := b transformed t ; 
+  b := r transformed t ; g := b transformed t ;
 
-  c := buildcycle(subpath(1,7) of g,subpath(1,7) of b) ;  
-  y := c transformed t ; m := y transformed t ; 
+  c := buildcycle(subpath(1,7) of g,subpath(1,7) of b) ;
+  y := c transformed t ; m := y transformed t ;
 
-  w := buildcycle(subpath(3,5) of r, subpath(3,5) of g,subpath(3,5) of b) ;  
+  w := buildcycle(subpath(3,5) of r, subpath(3,5) of g,subpath(3,5) of b) ;
 
   pushcurrentpicture ;
 
-  fill r withcolor       red   ; 
-  fill g withcolor       green ; 
-  fill b withcolor       blue  ; 
-  fill c withcolor white-red   ; 
-  fill m withcolor white-green ; 
-  fill y withcolor white-blue  ; 
-  fill w withcolor white       ; 
+  fill r withcolor       red   ;
+  fill g withcolor       green ;
+  fill b withcolor       blue  ;
+  fill c withcolor white-red   ;
+  fill m withcolor white-green ;
+  fill y withcolor white-blue  ;
+  fill w withcolor white       ;
 
-  for i = r,g,b,c,m,y : draw i withcolor .5white ; endfor ;   
+  for i = r,g,b,c,m,y : draw i withcolor .5white ; endfor ;
 
-  currentpicture := currentpicture xsized size ; 
+  currentpicture := currentpicture xsized size ;
 
   popcurrentpicture ;
-enddef ;   
+enddef ;
 
-% penpoint (i,2) of somepath -> inner / outer point 
+% penpoint (i,2) of somepath -> inner / outer point
 
-vardef penpoint expr pnt of p = 
-  save n, d ; numeric n, d ; 
-  (n,d) = if pair pnt : pnt else : (pnt,1) fi ; 
+vardef penpoint expr pnt of p =
+  save n, d ; numeric n, d ;
+  (n,d) = if pair pnt : pnt else : (pnt,1) fi ;
   (point n of p shifted ((penoffset direction n of p of currentpen) scaled d))
 enddef ;
 
-% nice: currentpicture := inverted currentpicture ;  
-
-primarydef p uncolored c = 
-  image 
-    (for i within p : 
-       addto currentpicture 
-       if stroked i or filled i : 
-         if filled i : contour else : doublepath fi pathpart i  
-         dashed dashpart i withpen penpart i 
-       else : 
-         also i  
-       fi  
-       withcolor c-(redpart i, greenpart i, bluepart i) ;    
-     endfor ; )  
-enddef ; 
-
-vardef inverted primary p = 
-  (p uncolored white) 
-enddef ;  
-
-primarydef p softened c = 
-  image 
-    (save cc ; color cc ; cc := tripled(c) ; 
-     for i within p : 
-       addto currentpicture 
-       if stroked i or filled i : 
-         if filled i : contour else : doublepath fi pathpart i  
-         dashed dashpart i withpen penpart i 
-       else : 
-        also i  
-       fi  
-       withcolor (redpart   cc * redpart   i, 
-                  greenpart cc * greenpart i, 
-                  bluepart  cc * bluepart  i) ;    
-     endfor ;) 
-enddef ; 
-
-vardef grayed primary p = 
-  image 
-    (for i within p : 
-       addto currentpicture  
-       if stroked i or filled i : 
-         if filled i : contour else : doublepath fi pathpart i  
-         dashed dashpart i withpen penpart i 
-       else : 
-         also i  
-       fi  
-       withcolor tripled(.30redpart i+.59greenpart i+.11bluepart i) ;    
-     endfor ; ) 
-enddef ; 
-
-% yes or no: "text" infont "cmr12" at 24pt ; 
+% nice: currentpicture := inverted currentpicture ;
+
+primarydef p uncolored c =
+  image
+    (for i within p :
+       addto currentpicture
+       if stroked i or filled i :
+         if filled i : contour else : doublepath fi pathpart i
+         dashed dashpart i withpen penpart i
+       else :
+         also i
+       fi
+       withcolor c-(redpart i, greenpart i, bluepart i) ;
+     endfor ; )
+enddef ;
+
+vardef inverted primary p =
+  (p uncolored white)
+enddef ;
+
+primarydef p softened c =
+  image
+    (save cc ; color cc ; cc := tripled(c) ;
+     for i within p :
+       addto currentpicture
+       if stroked i or filled i :
+         if filled i : contour else : doublepath fi pathpart i
+         dashed dashpart i withpen penpart i
+       else :
+        also i
+       fi
+       withcolor (redpart   cc * redpart   i,
+                  greenpart cc * greenpart i,
+                  bluepart  cc * bluepart  i) ;
+     endfor ;)
+enddef ;
+
+vardef grayed primary p =
+  image
+    (for i within p :
+       addto currentpicture
+       if stroked i or filled i :
+         if filled i : contour else : doublepath fi pathpart i
+         dashed dashpart i withpen penpart i
+       else :
+         also i
+       fi
+       withcolor tripled(.30redpart i+.59greenpart i+.11bluepart i) ;
+     endfor ; )
+enddef ;
+
+% yes or no: "text" infont "cmr12" at 24pt ;
 
 % let normalinfont = infont ;
-% 
-% numeric lastfontsize ; lastfontsize = fontsize defaultfont ;  
-% 
-% def infont primary name =  % no vardef, no expr 
-%   hide(lastfontsize := fontsize name) % no ; 
-%   normalinfont name 
-% enddef ; 
-% 
-% def scaledat expr size =  
-%   scaled (size/lastfontsize)  
-% enddef ; 
-% 
-% let at = scaledat ; 
+%
+% numeric lastfontsize ; lastfontsize = fontsize defaultfont ;
+%
+% def infont primary name =  % no vardef, no expr
+%   hide(lastfontsize := fontsize name) % no ;
+%   normalinfont name
+% enddef ;
+%
+% def scaledat expr size =
+%   scaled (size/lastfontsize)
+% enddef ;
+%
+% let at = scaledat ;
 
 % like decimal
 
-def condition primary b = if b : "true" else : "false" fi enddef ; 
+def condition primary b = if b : "true" else : "false" fi enddef ;
 
 % undocumented
 
-primarydef p stretched s = 
+primarydef p stretched s =
   begingroup
 % save pp ; path pp ; pp := p scaled s ;
   save pp ; path pp ; pp := p xyscaled s ;
-  (pp shifted ((point 0 of p) - (point 0 of pp)))  
+  (pp shifted ((point 0 of p) - (point 0 of pp)))
   endgroup
-enddef ; 
+enddef ;
 
-% yes or no, untested -) 
+% yes or no, untested -)
 
-def xshifted expr dx = shifted(dx,0) enddef ;  
-def yshifted expr dy = shifted(0,dy) enddef ;  
+def xshifted expr dx = shifted(dx,0) enddef ;
+def yshifted expr dy = shifted(0,dy) enddef ;
 
-% also handy 
+% also handy
 
-% right: str = readfrom ("abc" & ".def" ) ; 
+% right: str = readfrom ("abc" & ".def" ) ;
 % wrong: str = readfrom  "abc" & ".def"   ;
 
-% Every 62th read fails so we need to try again! 
+% Every 62th read fails so we need to try again!
 
-def readfile (expr name) = 
-  if (readfrom (name) <> EOF) : 
-    scantokens("input " & name & " ") ;
-  elseif (readfrom (name) <> EOF) : 
+% def readfile (expr name) =
+%   if (readfrom (name) <> EOF) :
+%     scantokens("input " & name & ";") ;
+%   elseif (readfrom (name) <> EOF) :
+%     scantokens("input " & name & ";") ;
+%   fi ;
+%   closefrom (name) ;
+% enddef ;
+%
+% this sometimes fails on the elseif, so :
+%
+
+def readfile (expr name) =
+  begingroup ; save ok ; boolean ok ;
+  if (readfrom (name) <> EOF) :
+    ok := false ;
+  elseif (readfrom (name) <> EOF) :
+    ok := false ;
+  else :
+    ok := true ;
+  fi ;
+  if not ok :
     scantokens("input " & name & " ") ;
-  fi  
+  fi ;
   closefrom (name) ;
-enddef ; 
+  endgroup ;
+enddef ;
 
-% permits redefinition of end in macro 
+% permits redefinition of end in macro
 
-inner end ; 
+inner end ;
 
 % real fun
 
@@ -1606,12 +1634,12 @@ def normalcolors =
   let withcolor = normalwithcolor ;
 enddef ;
 
-def resetcolormap = 
+def resetcolormap =
   color color_map[][][] ;
   normalcolors ;
-enddef ; 
+enddef ;
 
-resetcolormap ; 
+resetcolormap ;
 
 % color_map_resolution := 1000 ;
 %
@@ -1638,39 +1666,39 @@ enddef ;
 % def refill  suffix c = do_repath (1) (c) enddef ;
 % def redraw  suffix c = do_repath (2) (c) enddef ;
 % def recolor suffix c = do_repath (0) (c) enddef ;
-% 
-% color refillbackground ; refillbackground := (1,1,1) ; 
-% 
-% def do_repath (expr mode) (suffix c) text t = % can it be stroked and filled at the same time ? 
+%
+% color refillbackground ; refillbackground := (1,1,1) ;
+%
+% def do_repath (expr mode) (suffix c) text t = % can it be stroked and filled at the same time ?
 %   begingroup ;
-%   if mode=0 : save withcolor ; remapcolors ; fi ; 
-%   save _c_, _cc_, _f_, _b_ ; picture _c_, _cc_ ; color _f_ ; path _b_ ; 
-%   _c_ := c ; _b_ := boundingbox c ; c := nullpicture ; 
-%   for i within _c_ : 
+%   if mode=0 : save withcolor ; remapcolors ; fi ;
+%   save _c_, _cc_, _f_, _b_ ; picture _c_, _cc_ ; color _f_ ; path _b_ ;
+%   _c_ := c ; _b_ := boundingbox c ; c := nullpicture ;
+%   for i within _c_ :
 %     _f_ := (redpart i, greenpart i, bluepart i) ;
-%     if     bounded i : 
-%       setbounds c to pathpart i ; 
-%     elseif clipped i : 
-%       clip c to pathpart i ; 
-%     elseif stroked i : 
-%       addto c doublepath pathpart i 
-%         dashed dashpart i withpen penpart i 
-%         withcolor _f_ % (redpart i, greenpart i, bluepart i) 
+%     if     bounded i :
+%       setbounds c to pathpart i ;
+%     elseif clipped i :
+%       clip c to pathpart i ;
+%     elseif stroked i :
+%       addto c doublepath pathpart i
+%         dashed dashpart i withpen penpart i
+%         withcolor _f_ % (redpart i, greenpart i, bluepart i)
 %         if mode=2 : t fi ;
-%     elseif filled  i : 
-%       addto c contour pathpart i 
-%         withcolor _f_         
+%     elseif filled  i :
+%       addto c contour pathpart i
+%         withcolor _f_
 %         if (mode=1) and (_f_<>refillbackground) : t fi ;
 %     else :
 %       addto c also i ;
 %     fi ;
-%   endfor ;   
-%   setbounds c to _b_ ; 
-%   endgroup ; 
-% enddef ; 
+%   endfor ;
+%   setbounds c to _b_ ;
+%   endgroup ;
+% enddef ;
 
-% Thanks to Jens-Uwe Morawski for pointing out that we need 
-% to treat bounded and clipped components as local pictures. 
+% Thanks to Jens-Uwe Morawski for pointing out that we need
+% to treat bounded and clipped components as local pictures.
 
 def recolor suffix p = p := repathed (0,p) enddef ;
 def refill  suffix p = p := repathed (1,p) enddef ;
@@ -1684,152 +1712,152 @@ primarydef p redrawn   t = repathed(2,p) t enddef ;
 primarydef p retexted  t = repathed(3,p) t enddef ;
 primarydef p untexted  t = repathed(4,p) t enddef ;
 
-color refillbackground ; refillbackground := (1,1,1) ; 
+color refillbackground ; refillbackground := (1,1,1) ;
 
-vardef repathed (expr mode, p) text t = 
+vardef repathed (expr mode, p) text t =
   begingroup ;
-  if mode=0 : save withcolor ; remapcolors ; fi ; 
-  save _p_, _pp_, _f_, _b_, _t_ ; 
-  picture _p_, _pp_ ; color _f_ ; path _b_ ; transform _t_ ; 
-  _b_ := boundingbox p ; _p_ := nullpicture ; 
-  for i within p : 
+  if mode=0 : save withcolor ; remapcolors ; fi ;
+  save _p_, _pp_, _f_, _b_, _t_ ;
+  picture _p_, _pp_ ; color _f_ ; path _b_ ; transform _t_ ;
+  _b_ := boundingbox p ; _p_ := nullpicture ;
+  for i within p :
     _f_ := (redpart i, greenpart i, bluepart i) ;
-    if     bounded i : 
-      _pp_ := repathed(mode,i) t ; 
+    if     bounded i :
+      _pp_ := repathed(mode,i) t ;
       setbounds _pp_ to pathpart i ;
       addto _p_ also _pp_ ;
-    elseif clipped i : 
-      _pp_ := repathed(mode,i) t ; 
-      clip _pp_ to pathpart i ; 
+    elseif clipped i :
+      _pp_ := repathed(mode,i) t ;
+      clip _pp_ to pathpart i ;
       addto _p_ also _pp_ ;
-    elseif stroked i : 
-      addto _p_ doublepath pathpart i 
-        dashed dashpart i withpen penpart i 
-        withcolor _f_ % (redpart i, greenpart i, bluepart i) 
+    elseif stroked i :
+      addto _p_ doublepath pathpart i
+        dashed dashpart i withpen penpart i
+        withcolor _f_ % (redpart i, greenpart i, bluepart i)
         if mode=2 : t fi ;
-    elseif filled  i : 
-      addto _p_ contour pathpart i 
-        withcolor _f_         
+    elseif filled  i :
+      addto _p_ contour pathpart i
+        withcolor _f_
         if (mode=1) and (_f_<>refillbackground) : t fi ;
     elseif textual i : % textpart i <> "" :
-      if mode <> 4 : 
+      if mode <> 4 :
         % transform _t_ ;
-        % (xpart _t_, xxpart _t_, xypart _t_)  = (xpart  i, xxpart i, xypart i) ; 
-        % (ypart _t_, yypart _t_, yxpart _t_)  = (ypart  i, yypart i, yxpart i) ; 
-        % addto _p_ also 
+        % (xpart _t_, xxpart _t_, xypart _t_)  = (xpart  i, xxpart i, xypart i) ;
+        % (ypart _t_, yypart _t_, yxpart _t_)  = (ypart  i, yypart i, yxpart i) ;
+        % addto _p_ also
         %   textpart i infont fontpart i % todo : other font
-        %   transformed _t_ 
-        %   withpen penpart i  
-        %   withcolor _f_ 
+        %   transformed _t_
+        %   withpen penpart i
+        %   withcolor _f_
         %   if mode=3 : t fi ;
         addto _p_ also i if mode=3 : t fi ;
       fi ;
     else :
       addto _p_ also i ;
     fi ;
-  endfor ;   
-  setbounds _p_ to _b_ ; 
-  _p_ 
-  endgroup 
-enddef ; 
+  endfor ;
+  setbounds _p_ to _b_ ;
+  _p_
+  endgroup
+enddef ;
 
 
 
 
-% After a question of Denis on how to erase a z variable, Jacko 
-% suggested to assign whatever to x and y. So a clearz 
-% variable can be defined as: 
+% After a question of Denis on how to erase a z variable, Jacko
+% suggested to assign whatever to x and y. So a clearz
+% variable can be defined as:
 %
-% vardef clearz@# = 
-%   x@# := whatever ; 
-%   y@# := whatever ; 
-% enddef ; 
+% vardef clearz@# =
+%   x@# := whatever ;
+%   y@# := whatever ;
+% enddef ;
 %
-% but Jacko suggested a redefinition of clearxy: 
+% but Jacko suggested a redefinition of clearxy:
 %
 % def clearxy text s =
-%  clearxy_index_:=0; 
-%  for $:=s: 
+%  clearxy_index_:=0;
+%  for $:=s:
 %    clearxy_index_:=clearxy_index_+1; endfor;
-%  if clearxy_index_=0: 
+%  if clearxy_index_=0:
 %    save x,y;
-%  else: 
+%  else:
 %    forsuffixes $:=s: x$:=whatever; y$:=whatever; endfor;
 %  fi
 % enddef;
 %
-% which i decided to simplify to: 
+% which i decided to simplify to:
 
 def clearxy text s =
-  if false for $ := s : or true endfor : 
+  if false for $ := s : or true endfor :
     forsuffixes $ := s : x$ := whatever ; y$ := whatever ; endfor ;
-  else : 
+  else :
     save x, y ;
   fi
 enddef ;
 
-% so now we can say: clearxy ; as well as clearxy 1, 2, 3 ; 
+% so now we can say: clearxy ; as well as clearxy 1, 2, 3 ;
 
-% show x0 ; z0 = (10,10) ; 
-% show x0 ; x0 := whatever ; y0 := whatever ; 
+% show x0 ; z0 = (10,10) ;
+% show x0 ; x0 := whatever ; y0 := whatever ;
 % show x0 ; z0 = (20,20) ;
-% show x0 ; clearxy 0 ; 
+% show x0 ; clearxy 0 ;
 % show x0 ; z0 = (30,30) ;
 
 primarydef p smoothed d =
-  (p llmoved (-xpart paired(d),0) -- p lrmoved (-xpart paired(d),0) {right} .. 
-   p lrmoved (0,-ypart paired(d)) -- p urmoved (0,-ypart paired(d)) {up}    .. 
+  (p llmoved (-xpart paired(d),0) -- p lrmoved (-xpart paired(d),0) {right} ..
+   p lrmoved (0,-ypart paired(d)) -- p urmoved (0,-ypart paired(d)) {up}    ..
    p urmoved (-xpart paired(d),0) -- p ulmoved (-xpart paired(d),0) {left}  ..
-   p ulmoved (0,-ypart paired(d)) -- p llmoved (0,-ypart paired(d)) {down}  .. cycle) 
+   p ulmoved (0,-ypart paired(d)) -- p llmoved (0,-ypart paired(d)) {down}  .. cycle)
 enddef ;
 
-primarydef p cornered c = 
-  ((point 0 of p) shifted (c*(unitvector(point 1 of p - point 0 of p))) -- 
+primarydef p cornered c =
+  ((point 0 of p) shifted (c*(unitvector(point 1 of p - point 0 of p))) --
    for i=1 upto length(p) :
-     (point i-1 of p) shifted (c*(unitvector(point i   of p - point i-1 of p))) -- 
+     (point i-1 of p) shifted (c*(unitvector(point i   of p - point i-1 of p))) --
      (point i   of p) shifted (c*(unitvector(point i-1 of p - point i   of p))) ..
-     controls point i of p .. 
-   endfor cycle) 
+     controls point i of p ..
+   endfor cycle)
 enddef ;
 
-% cmyk color support 
+% cmyk color support
 
 vardef cmyk(expr c,m,y,k) =
   (1-c-k,1-m-k,1-y-k)
 enddef ;
 
-% handy 
+% handy
 
-vardef bbwidth  (expr p) = 
-  (if known p : 
-     if path p or picture p : 
-       xpart (lrcorner p - llcorner p) 
-     else : 0 fi else : 0 
+vardef bbwidth  (expr p) =
+  (if known p :
+     if path p or picture p :
+       xpart (lrcorner p - llcorner p)
+     else : 0 fi else : 0
    fi )
-enddef ; 
+enddef ;
 
-vardef bbheight (expr p) = 
-  (if known p : if path p or picture p : 
-     ypart (urcorner p - lrcorner p) 
-     else : 0 fi else : 0 
+vardef bbheight (expr p) =
+  (if known p : if path p or picture p :
+     ypart (urcorner p - lrcorner p)
+     else : 0 fi else : 0
    fi)
-enddef ; 
+enddef ;
 
-color nocolor ; numeric noline ; % both unknown signals 
+color nocolor ; numeric noline ; % both unknown signals
 
 def dowithpath (expr p, lw, lc, bc) =
-  if known p : 
-    if known bc : 
+  if known p :
+    if known bc :
       fill p withcolor bc ;
-    fi ; 
-    if known lw and known lc : 
+    fi ;
+    if known lw and known lc :
       draw p withpen pencircle scaled lw withcolor lc ;
-    elseif known lw : 
+    elseif known lw :
       draw p withpen pencircle scaled lw ;
-    elseif known lc : 
+    elseif known lc :
       draw p withcolor lc ;
-    fi ; 
-  fi ; 
+    fi ;
+  fi ;
 enddef ;
 
 % result from metafont discussion list (denisr/boguslawj)
@@ -1837,122 +1865,165 @@ enddef ;
 def ]]  = ] ] enddef ; def ]]] = ] ] ] enddef ;
 def [[  = [ [ enddef ; def [[[ = [ [ [ enddef ;
 
-% not prefect, but useful since it removes redundant points.
+% not perfect, but useful since it removes redundant points.
+
+% vardef dostraightened(expr sign, p) =
+%   if length(p)>2 : % was 1, but straight lines are ok
+%     save pp ; path pp ;
+%     pp := point 0 of p ;
+%     for i=1 upto length(p)-1 :
+%       if round(point i of p) <> round(point length(pp) of pp) :
+%         pp := pp -- point i of p ;
+%       fi ;
+%     endfor ;
+%     save n, ok ; numeric n ; boolean ok ;
+%     n := length(pp) ; ok := false ;
+% if n>2 :
+%     for i=0 upto n : % evt hier ook round
+%      if unitvector(round(point i                        of pp  -
+%                    point if i=0 : n else : i-1 fi of pp)) <>
+%  sign * unitvector(round(point if i=n : 0 else : i+1 fi of pp  -
+%                    point i                        of pp)) :
+%         if ok : -- else : ok := true ; fi point i of pp
+%       fi
+%     endfor
+%     if ok and (cycle p) : -- cycle fi
+% else :
+%   pp
+% fi
+%   else :
+%     p
+%   fi
+% enddef ;
+
+% vardef simplified expr p =
+%   (reverse dostraightened(+1,dostraightened(+1,reverse p)))
+% enddef ;
+
+% vardef unspiked   expr p =
+%   (reverse dostraightened(-1,dostraightened(-1,reverse p)))
+% enddef ;
 
-vardef dostraightened(expr sign, p) = 
-  if length(p)>2 : % was 1, but straight lines are ok 
-    save pp ; path pp ; 
+% simplified : remove same points as well as redundant points
+% unspiked   : remove same points as well as areas with zero distance
+
+vardef dostraightened(expr sign, p) =
+  save _p_, _q_ ; path _p_, _q_ ;
+  _p_ := p ;
+  forever :
+    _q_ := dodostraightened(sign, _p_) ;
+    exitif length(_p_) = length(_q_) ;
+    _p_ := _q_ ;
+  endfor ;
+  _q_
+enddef ;
+
+vardef dodostraightened(expr sign, p) =
+  if length(p)>2 : % was 1, but straight lines are ok
+    save pp ; path pp ;
     pp := point 0 of p ;
-    for i=1 upto length(p)-1 : 
-      if round(point i of p) <> round(point length(pp) of pp) : 
+    for i=1 upto length(p)-1 :
+      if round(point i of p) <> round(point length(pp) of pp) :
         pp := pp -- point i of p ;
-      fi ; 
+      fi ;
     endfor ;
-    save n, ok ; numeric n ; boolean ok ;  
-    n := length(pp) ; ok := false ; 
-if n>2 : 
-    for i=0 upto n : % evt hier ook round 
- 
-     if unitvector(round(point i                        of pp  - 
-                   point if i=0 : n else : i-1 fi of pp)) <> 
- sign * unitvector(round(point if i=n : 0 else : i+1 fi of pp  - 
-                   point i                        of pp)) : 
-        if ok : -- else : ok := true ; fi point i of pp 
-      fi 
-
-    endfor   
-    if ok and (cycle p) : -- cycle fi 
-else : 
-  pp 
-fi 
-  else : 
-    p 
-  fi 
-enddef ; 
-
-% simplified : remove same points as well as redundant points 
-% unspiked   : remove same points as well as areas with zero distance 
-
-% vardef simplified expr p = dostraightened(+1,p) enddef ;  
-% vardef unspiked   expr p = dostraightened(-1,p) enddef ;  
+    save n, ok ; numeric n ; boolean ok ;
+    n := length(pp) ; ok := false ;
+    if n>2 :
+      for i=0 upto n : % evt hier ook round
+        if unitvector(round(point i                        of pp  -
+                            point if i=0 : n else : i-1 fi of pp)) <>
+    sign * unitvector(round(point if i=n : 0 else : i+1 fi of pp  -
+                            point i                        of pp)) :
+          if ok : -- else : ok := true ; fi point i of pp
+        fi
+      endfor
+      if ok and (cycle p) : -- cycle fi
+    else :
+      pp
+    fi
+  else :
+    p
+  fi
+enddef ;
 
 vardef simplified expr p =
-  (reverse dostraightened(+1,dostraightened(+1,reverse p)))
+  dostraightened(+1,p)
 enddef ;
 
 vardef unspiked   expr p =
-  (reverse dostraightened(-1,dostraightened(-1,reverse p)))
+  dostraightened(-1,p)
 enddef ;
 
-% path p ; 
-% p := (2cm,1cm) -- (2cm,1cm) -- (2cm,1cm) -- (3cm,1cm) -- 
-%      (4cm,1cm) -- (4cm,2cm) -- (4cm,2.5cm) -- (4cm,3cm) -- 
-%      (3cm,3cm) -- (2cm,3cm) -- (1cm,3cm) -- (-1cm,3cm) -- 
-%      .5[(-1cm,3cm),(1cm,1cm)] -- (1cm,1cm) -- cycle ; 
-% 
-% p := unitcircle scaled 4cm ; 
-% 
-% drawpath p ; drawpoints p ; drawpointlabels p ; 
-% p := p shifted (4cm,0) ; p := straightened p ; 
-% drawpath p ; drawpoints p ; drawpointlabels p ; 
-% p := p shifted (4cm,0) ; p := straightened p ; 
-% drawpath p ; drawpoints p ; drawpointlabels p ; 
+% path p ;
+% p := (2cm,1cm) -- (2cm,1cm) -- (2cm,1cm) -- (3cm,1cm) --
+%      (4cm,1cm) -- (4cm,2cm) -- (4cm,2.5cm) -- (4cm,3cm) --
+%      (3cm,3cm) -- (2cm,3cm) -- (1cm,3cm) -- (-1cm,3cm) --
+%      .5[(-1cm,3cm),(1cm,1cm)] -- (1cm,1cm) -- cycle ;
+%
+% p := unitcircle scaled 4cm ;
+%
+% drawpath p ; drawpoints p ; drawpointlabels p ;
+% p := p shifted (4cm,0) ; p := straightened p ;
+% drawpath p ; drawpoints p ; drawpointlabels p ;
+% p := p shifted (4cm,0) ; p := straightened p ;
+% drawpath p ; drawpoints p ; drawpointlabels p ;
 
-% new 
+% new
 
 path originpath ; originpath := origin -- cycle ;
 
-vardef unitvector primary z = 
-  if abs z = abs origin : z else : z/abs z fi  
+vardef unitvector primary z =
+  if abs z = abs origin : z else : z/abs z fi
 enddef;
 
-% also new 
+% also new
 
-vardef anchored@#(expr p, z) =  
+vardef anchored@#(expr p, z) =
   p shifted (z + (labxf@#*lrcorner p + labyf@#*ulcorner p
        + (1-labxf@#-labyf@#)*llcorner p))
 enddef ;
 
 % epsed(1.2345)
 
-vardef epsed (expr e) = 
-  e if e>0 : + eps elseif e<0 : - eps fi  
-enddef ; 
+vardef epsed (expr e) =
+  e if e>0 : + eps elseif e<0 : - eps fi
+enddef ;
 
-% handy 
+% handy
 
-def withgray primary g = 
-  withcolor (g,g,g) 
-enddef ; 
+def withgray primary g =
+  withcolor (g,g,g)
+enddef ;
 
-% for metafun 
+% for metafun
 
-if unknown darkred    : color darkred    ; darkred    := .625(1,0,0) fi ; 
-if unknown darkyellow : color darkyellow ; darkyellow := .625(1,1,0) fi ; 
-if unknown darkgray   : color darkgray   ; darkgray   := .625(1,1,1) fi ; 
-if unknown lightgray  : color lightgray  ; lightgray  := .875(1,1,1) fi ; 
+if unknown darkred    : color darkred    ; darkred    := .625(1,0,0) fi ;
+if unknown darkyellow : color darkyellow ; darkyellow := .625(1,1,0) fi ;
+if unknown darkgray   : color darkgray   ; darkgray   := .625(1,1,1) fi ;
+if unknown lightgray  : color lightgray  ; lightgray  := .875(1,1,1) fi ;
 
-% an improved plain mp macro 
+% an improved plain mp macro
 
-vardef center primary p = 
-  if pair p : p else : .5[llcorner p, urcorner p] fi  
+vardef center primary p =
+  if pair p : p else : .5[llcorner p, urcorner p] fi
 enddef;
 
-% new, yet undocumented 
-
-vardef rangepath (expr p, d, a) = 
-  (if length p>0 :  
-     (d*unitvector(direction 0 of p) rotated a) 
-      shifted point 0 of p 
-     -- p -- 
-     (d*unitvector(direction length(p) of p) rotated a) 
-      shifted point length(p) of p 
-   else : 
-     p 
+% new, yet undocumented
+
+vardef rangepath (expr p, d, a) =
+  (if length p>0 :
+     (d*unitvector(direction 0 of p) rotated a)
+      shifted point 0 of p
+     -- p --
+     (d*unitvector(direction length(p) of p) rotated a)
+      shifted point length(p) of p
+   else :
+     p
    fi)
-enddef ; 
+enddef ;
 
-% under construction 
+% under construction
 
 vardef straightpath(expr a, b, method) =
   if (method<1) or (method>6)  :
@@ -1994,7 +2065,7 @@ vardef straightpath(expr a, b, method) =
   fi
 enddef ;
 
-% handy for myself 
+% handy for myself
 
 def addbackground text t =
   begingroup ; save p ; picture p ;
@@ -2006,55 +2077,55 @@ enddef ;
 % makes a (line) into an infinite one (handy for calculating
 % intersection points
 
-vardef infinite expr p = 
-  (-infinity*unitvector(direction 0 of p) 
-    shifted point 0 of p 
-   -- p -- 
-   +infinity*unitvector(direction length(p) of p) 
+vardef infinite expr p =
+  (-infinity*unitvector(direction 0 of p)
+    shifted point 0 of p
+   -- p --
+   +infinity*unitvector(direction length(p) of p)
     shifted point length(p) of p)
-enddef ; 
+enddef ;
 
 % obscure macros: create var from string and replace - and :
 % (needed for process color id's)
 
 string _clean_ascii[] ;
 
-_clean_ascii[ASCII "-"] := "_" ;  
-_clean_ascii[ASCII ":"] := "_" ;  
-_clean_ascii[ASCII "."] := "_" ;  
+_clean_ascii[ASCII "-"] := "_" ;
+_clean_ascii[ASCII ":"] := "_" ;
+_clean_ascii[ASCII "."] := "_" ;
 
-vardef cleanstring (expr s) = 
-  save ss ; string ss, si ; ss = "" ;  
-  for i=0 upto length(s) : 
-    si := substring(i,i+1) of s ; 
+vardef cleanstring (expr s) =
+  save ss ; string ss, si ; ss = "" ;
+  for i=0 upto length(s) :
+    si := substring(i,i+1) of s ;
     ss := ss & if known _clean_ascii[ASCII si] : _clean_ascii[ASCII si] else : si fi ;
   endfor ;
-  ss 
-enddef ; 
+  ss
+enddef ;
 
-vardef setunstringed (expr s, v) = 
-  scantokens(cleanstring(s)) := v ; 
+vardef setunstringed (expr s, v) =
+  scantokens(cleanstring(s)) := v ;
 enddef ;
 
-vardef setunstringed (expr s, v) = 
-  scantokens(cleanstring(s)) := v ; 
+vardef setunstringed (expr s, v) =
+  scantokens(cleanstring(s)) := v ;
 enddef ;
 
-vardef getunstringed (expr s) = 
-  scantokens(cleanstring(s)) 
+vardef getunstringed (expr s) =
+  scantokens(cleanstring(s))
 enddef ;
 
-vardef unstringed (expr s) = 
-  expandafter known scantokens(cleanstring(s)) 
+vardef unstringed (expr s) =
+  expandafter known scantokens(cleanstring(s))
 enddef ;
 
-% new 
+% new
 
-vardef colorpart(expr i) = 
-  (redpart i, greenpart i,bluepart i) 
-enddef ; 
+vardef colorpart(expr i) =
+  (redpart i, greenpart i,bluepart i)
+enddef ;
 
 
-% done 
+% done
 
 endinput ;