  This paper studies controllability properties of recurrent neural networks.
The new contributions are:
  (1) an extension of the result in the previous paper "Complete
controllability of continuous-time recurrent neural networks" (Sontag and
Sussmann) to a slightly different model, where inputs appear in an affine form,
  (2) a formulation and proof of a necessary and sufficient condition, in terms
of local-local controllability, and
  (3) a complete analysis of the 2-dimensional case for which the hypotheses
made in previous work do not apply
