Thanks all for the input - I think I have a better understanding of derivative work. I think that I'll look for a paper on the algorithm and work from there.
For the curious, the "hypothetical" code in question was from here <https://codetobuy.com/downloads/brent-dekker-method-as-a-root-finding-method-of-any-equation/> : Since he posted it in "algorithmic" form, and I had no interest in purchasing his code to run in Matlab (since Matlab likely has something faster anyhow), I was puzzled about what I might be able to do with my pure Scheme version. On Tue, Jun 29, 2021 at 9:22 AM <to...@tuxteam.de> wrote: > On Tue, Jun 29, 2021 at 01:52:56PM +0000, Nate Rosenbloom wrote: > > > > > This reason is not stated in the Stack Exchange post, and I believe > > > it’s inaccurate (although, I am not a lawyer either). I think the > > > reason is that you are reading the original implementation to write > > > your own, so you are some kind of a compiler, or translator (as for > > > human spoken languages). As such, what you write is mostly the other > > > person’s work, so you should not claim copyright about it. > > > > Sorry, I should have been more specific, the rewritten algorithm would > not be the same, but it would be a derivative work and still covered by > copyright of the original work. > > I think the legal concept of "derivative work" is far more complex than > we'd all like. See [1] to get an idea. > > With the caveat that I'm not a lawyer (heh), I think the "red line" lies > between those two extremes: (a) you read the original, understand the > algorithm and write your program based on this understanding. Best if > you forget details like variable naming, program structure, etc. Only > the "pure" algorithm survives, and (b) you translate the program line > by line (although that would be pretty hard between C and, say, idiomatic > Scheme). (a) is almost certainly not a derivative work, while (b) would > be, most probably. > > To make sure you can cleanly /prove/ you did (a), some do what is called > a "clean room implementation". Fred looks at the original program and > tells Gina "how it works", and Gina implements the new one. > > Cheers > > [1] https://copyleft.org/guide/comprehensive-gpl-guidech5.html > > - t >