Identifiability and well-posedness in nonlinear system I/O modeling

If a specified set of parameterized nonlinear state differential equations possesses an equivalent input-output differential operator model, then the latter model has the potential for deciding the issue of the identifiability property of the former model in a straightforward manner. This property is discussed in relation to the property of well-posedness for the least-squares parameter identification of a class of input-output models that are separable in the parameters