I recently have gone through my entire library and retagged the whole thing using a more consistent system. Yesterday, I had to reformat and then reinstall Logos. For some inexplicable reason, not all of my PBBs and new tags had synced properly (seems completely random too). That said, when I retagged my whole library, I tagged everything either Read or Unread. Therefore, all of the books that didn't sync the tags right do not have either of those tags on them. Rather than wading through all 4,500 books, it would be nice to filter out all of the books that had synced the new tagging system properly.
Essentially then, I need to filter NOT mytag:unread AND NOT mytag:read, but that doesn't work. Does anyone know a way of doing this?