We have a situation in which we developed some software, where four previous members of our research group participated some time ago. Then they left the group, and said that from then on, they did not want to work on further developments of the code.
Now we have used that code, which has evolved a bit since they left, and we have applied it to some other contexts, in which we have made some discoveries, and it turns out we can file a patent.
The question here is, the old members that left the group and did not want to work on further developments of the code, must they be included in the patent as authors/inventors?
I would say the answer is no, since they said they did not want to work on further developments of the code, but since this software tool was a key step for the discovery reported in the patent, and they participated a bit in the past on the software, they should perhaps be included as coauthors/inventors.
Should they be included?