A footnote to Lee Giles msg. Polynomial networks, analog perceptrons,
Kolmogorov theorem and invariances were described in an old paper with
Werner Reichardt.
``On the representation of multi-input systems: computational
properties of polynomial algorithms,'' (T. Poggio and W. Reichardt). {\it Biol.
Cyber.}, {\bf 37}, 167-186, 1980.