When splitting an issue of lets say 20SP into two a 13 and 8, what to do with the parent issue in the backlog. Does it exist in the backlog after splitting up with its original estimate having its status moved to "In Progress" when one is moved into a sprint and people starts working on it? Or is it common to reject the issue with a Resolution "Duplicate".
In short, what is the proper procedure when splitting up an issue?