I've been reading some formal language theory papers, and I've come across a term that I don't understand.
The paper will often refer to a set being "effectively closed under intersection" or other operations. What does "effectively" mean here? How does this differ from normal closure?
For reference, the paper I'm seeing these in is:
M. Daley and I. McQuillan. Formal modelling of viral gene compression. International Journal of Foundations of Computer Science, 16(3):453–469, 2005.