7We implicitly assume in the following derivations that the structure of the 
function is appropriate to
our needs; later we will define a specific 
that will always work, but here we want to leave the structure of
the function general.
7We implicitly assume in the following derivations that the structure of the function is appropriate to
our needs; later we will define a specific that will always work, but here we want to leave the structure of
the function general.