Necessary conditions are obtained for a time-varying network to nontrivially realize a time-invariant terminal behavior. Networks containing one type of time-varying element and more than one type of time-varying element are considered. Some implications of the results are that with one type of time-varying element present, there must be at least two time-varying components, and with time-varying

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networks, there must be at least two time-varying components of each type in order to realize a time-variant terminal behavior. There are in addition certain constraints on the derivatives of the component values.