> Prompting Claude generates something that did not exist, through decisions the model makes about structure, naming, pattern, and implementation.

LLMs don't make decisions. Their output is completely determined by an algorithm using the human prompt, fixed weights, and a random seed. No different than the many effects humans use in image or audio editors. Nobody ever questioned whether art made using only those effects on a blank canvas was subject to copyright.

Fourier theory says that any sound, however complex, can be synthesized by summing sines and cosines. That's what an LLM does, if you twist the metaphor enough. It synthesizes complex outputs from simpler basis functions that are, or should be, uncopyrightable.

The fact that it inferred those basis functions from studying copyrighted works doesn't seem relevant. Nor does the fact that the "Fourier sums" sometimes coincide with larger fragments of works that are copyrighted. How weird would it be if that didn't happen?