•Given an ND network,
what is its behavior, i.e. what is the set of all PI/PO pairs that are related?
–this question is not
straightforward.
•For a deterministic,
well-defined network, there is exactly one PO vector for each PI vector
–however, if there are
some external don’t cares, then there may be several PO vectors for a PI vector,
–but don’t cares are
well understood.