Is there any way to have two windows of the same PDF document, open at the same time and to edit both windows at the same time, so the changes that you make in one window it is reflected in the other windows? So you can be reading some part of the document but at the same time, in another window make a comment at the end of the document, or read different parts of the document at the same time.

Right now I'm making a copy of the document (two different files) but it's very uncomfortable because I have to update (through File/Save As) the copy of the document every time I make a modification on the "principal" file.

Exactly as works Microsoft Word 2013 feature View/New Window
(http://superuser.com/questions/55279...parate-windows)