anchor.diff:  implementation
   
   uses
  -  Forms;
  +  Forms, Math;
   
   const
     RichEditModuleName = 'RICHED20.DLL';
  
positive.code:       pt := pt2;
      end;
      if (offset = lines.Count-1) then begin   // bottom part
        Perform(EM_POSFROMCHAR, Integer(@pt2), Perform(EM_LINEINDEX, offset+1, 0));
        if (IsHighlighted(offset)) then begin
          bmp.Canvas.FillRect(Rect(0, 0, ClientWidth, pt2.Y-pt.Y));
          bmp.Height := pt2.Y-pt.Y;
  
negative.code:     FillRect(Rect(0, 0, FGutterWidth-10, lh));
      while (offset < lines.Count-1) and (r.Top < Height) do begin
        Perform(EM_POSFROMCHAR, Integer(@pt2), Perform(EM_LINEINDEX, offset+1, 0));
        if (pt2.Y < pt.Y) then pt2.Y := pt.Y + 16;
        {$IFNDEF HIGHLIGHT_TOKEN}
        if (IsHighlighted(offset)) then begin
          bmp.Canvas.FillRect(Rect(0, 0, ClientWidth, pt2.Y-pt.Y));
  