Re: Derivative Licensing Question

Stefan Ram <ram@zedat.fu-berlin.de> wrote:

  . Now your program clearly has nothing to do with the original
  anymore. You just used that to get started but then gradually
  transformed it into your own code. So, is "B = 7" now free from
  any copyright of the original author of "A = 2"? At what point
  during the transition exactly did the copyright disappear?

Your last question is the key, and (under US law) is something that can
only ultimately be determined by a court case.  The reason why is that
the law around copyright decides "infringement" based on factors such
as:

The nature of the change;
The amount of change made;
The use of the changed code;
The effect of the copy upon the market value of the original;
etc.

And, you'll notice a disconcerting issue with all of those factors. 
They are not absolute binary decisions (is 2 less than 4).  They are
subjective judgement calls.  And barring the invention of a "copyright
AI oracle", the true subjectiveness (meaning did, or did not infringe)
can only be determined by a court during a lawsuit.