Union of Approximation and Intervening variables?

[artofscience]

Note the following:

class Approximation:
def g
def dg
def ddg
def update
def clip

class Intervening:
def y
def dydx
def ddyddx
def update
def clip

Woh? They are so similar. Why not make a single class?

Both are actually just functions with derivatives...

Then we can e.g. do things like

approx = Taylor2(Taylor1(resp(2)=Taylor1(MMA()), resp(3)=Taylor2(Taylor1(Reciprocal())), resp(0)=Linear())

[artofscience]

side note: it also looks like approximation and intervening (or maybe in future "mapping") could inherit from "problem", since "problem" is also "just" a function with g, dg, ddg