At 03:40 PM 11/21/05 -0500, Riad S. Wahby wrote:

It's a violation of copyright to translate a book into a different language and sell it as your own, even if the two languages are

slightly

at odds with regard to, e.g., their colloquialisms (i.e., the translation is "lossy" in some way). It's about the chain of derivation, not the subjective experience.

No, its about the subjective (semantic) experience. An MP3 is the "same", even if it is bitwise distinct. Using a patented algorithm is illegal (fnord), even if written in a distinct language, for a different instruction set, and even if derived independantly. (Contrast with interfaces, which if implemented in a clean-room situation, are not protectable.) All this under current US law, no endorsement implied. Now making semantically distinct near-copies (aka, parodies) are protected under the same rules, precisely because of the semantic distinction. Application to comp sci should be obvious. An interesting question is, say Bruce patented Blowfish, but you use e instead of pi to seed the tables. If he had patented the structure and not the details, this would be enforceable; a question remains as to how much you could vary the details of the process and get away with it. (Of course, a patented block cipher is about as useful as say IDEA, heh..)