lcamtuf 
If you ask AI to rewrite the entirety of an open-source program, do you still need to abide by the original license? In philosophy, this problem is known as the Slop of Theseus
Kevin Riggle@lcamtuf actual answer: of course you do, it’s prima facie a derivative work, same as if you had rewritten the program by hand.
Ben Galehouse
Tom BortelsAssuming you used the original source code to derive the detailed spec, then yes, that too is a derivative work.
The "viral" nature of that sort of license has bothered me for a long time. It's always been simultaneously overly far reaching and impossible to realistically enforce.
But here's an interesting question:
If you do not execute the code - did you accept the license? Does simply reading it sufficiently to be able to write a spec bind you to that license? That seems a bit too much.
ArneBab@tbortels if you do not accept the license, you do not have any right to use the code. It’s "all rights reserved" then. @lcamtuf @bgalehouse @kevinr
@lcamtuf @ArneBab @kevinr @bgalehouse
"Use" isn't part of the GPL. And "all rights reserved" means normal copyright law, not "you get no rights at all".
The GPL defines "modify" and "propagate" as the activities it burdens. If I modify the code, and propagate it, i have a legal burden under the license. Otherwise, I don't.
IANAL, but I don't think reading the code and re-implementing a work-alike without incorporating the original code is "modify" - it's "replace".
I understand that's where "clean rooms" come into play, but that always felt like splitting hairs and giving copyright too much power - it's about physical books, not ideas. The farther we move from the original intent, the weaker a strong copyright stance becomes.
I think you could make an argument that reading code to understand it's interfaces, explicitly rejecting accepting any license, then implementing compatible code is well within the normal copyright definition of "fair use", or should be if we aren't all copyright lawyers. More importantly, it's healthy for Society and the art. If I can read a book under copyright and write a detailed book report, I should be able to read provided source code and do the same. To the extent that we've strayed away from that, the legal system has failed and needs correction.
@tbortels yes, not accepting the license means regular copyrights.
But your arguments afterwards rely on rights the GPL gives you -- you only get them after you accept the license.
EDIT: because "if we aren’t allowed … under copyright" ← we aren’t. That’s the point.
As long as there’s no NDA (there isn’t for GPL), we *can* write a spec. But the one implementing it *must not* know the code.
@ArneBab @kevinr @lcamtuf @bgalehouse
Fair use isn't something the GPL grants you. That's what I'm trying to work out - set the GPL aside for a moment.
Does regular copyright fair use give me the right to look at the freely provided source code, make a mental model, and re-implement a workalike if I don't re-use the original source?
Pretend it's just me and not an AI, because that throws a whole new set of confusion into the mix.
BSD did it against regular copyright. Not sure this is all that different.
@tbortels as far as I know, and as the article https://www.allaboutcircuits.com/news/how-compaqs-clone-computers-skirted-ibms-patents-and-gave-rise-to-eisa/ reinforces, fair use does not give you the right to re-implement the code.
Doesn’t matter whether you make a mental model as the intermediate step.
Only the clean room re-implementation gets out of that.