The class of piecewise rational functions is quite large, and for the
rest of the paper we will confine ourselves to two types of functions in
this class. Definitions of these two piecewise rational functions will
be carried out in this section. Also, from this section on we will
refer to the set of piecewise rational functions which are also smooth
activations (see definition #defofsmooth#434>) as #tex2html_wrap_inline2823#, and to networks using them as #tex2html_wrap_inline2825# nets.