  Entanglement, which is an essential characteristic of quantum mechanics, is
the key element in potential practical quantum information and quantum
communication systems. However, there are many open and fundamental questions
(relating to entanglement measures, sudden death, etc.) that require a deeper
understanding. Thus, we are motivated to investigate a simple but non-trivial
correlated two-body continuous variable system in the absence of a heat bath,
which facilitates an \underline{exact} measure of the entanglement at all
times. In particular, we find that the results obtained from all well-known
existing entanglement measures agree with each other but that, in practice,
some are more straightforward to use than others.
