AFAIK there is no amount of changes you can make to a work that will make it stop being a derivative work. That's why reimplementations of license-encumbered s

AFAIK there is no amount of changes you can make to a work that will make it stop being a derivative work. That's why reimplementations of license-encumbered software have to be careful to have one team study the software that is to be reimplemented and describe what it does and another teams reads this specification and implements the substitute without ever looking at the original software. https://en.wikipedia.org/wiki/Clean_room_design https://en.wikipedia.org/wiki/Clean_room_design