# Genetic programming for a function of functions of inputs

Given a vector of variables $X=(x_1, x_2, ..., x_n)$ I have previously used genetic programming for deriving an expression for a function $y=f(X)$ from a training dataset of tuples $<X, y>$.

Now, I need a way to learn the target as a (predefined) function of (evolved) functions of inputs. Say $f(X)=\frac{g(X)+b}{h(X)+c}$ is the predefined form of the target function. In this case, The GP evolution searches the space of possible forms of $g(X)$ and $h(X)$ in parallel and finally outputs two best expressions for both of them.

Is any variant of genetic programming proposed in the literature for this scenario?