That would be an example for a derivative with respect to x, of two two-argument functions, nested four times.
Any obvious patterns for the Eagle-eyed programmer wizzes of you?
\begin{doublespace}
\noindent\(\(f^{(1,0)}(f(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))),g(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))) \\
\left(f^{(1,0)}(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))) \right.\\
\left(g^{(1,0)}(x,y) f^{(0,1)}(f(x,y),g(x,y))+f^{(1,0)}(x,y) f^{(1,0)}(f(x,y),g(x,y))\right)+\left.f^{(0,1)}\right(f(f(x,y),g(x,y)),\\
\left.g(f(x,y),g(x,y))) \left(f^{(1,0)}(x,y) g^{(1,0)}(f(x,y),g(x,y))+g^{(1,0)}(x,y) g^{(0,1)}(f(x,y),g(x,y))\right)\right)+\\
f^{(0,1)}(f(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))),g(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))) \\
\left(g^{(0,1)}(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))) \right.\\
\left(f^{(1,0)}(x,y) g^{(1,0)}(f(x,y),g(x,y))+g^{(1,0)}(x,y) g^{(0,1)}(f(x,y),g(x,y))\right)+\\
\left(g^{(1,0)}(x,y) f^{(0,1)}(f(x,y),g(x,y))+f^{(1,0)}(x,y) f^{(1,0)}(f(x,y),g(x,y))\right) \\
\left.g^{(1,0)}(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))\right)\)\)
\end{doublespace}
Edit: Does the Latex work right now? Seems to be only an unknown image on my end... Writing it all by hand is pretty... long and error prone, so I'd like to avoid that <.<
Edit: Here is the actual final result to be viewed. It's the Nabla operator on a complex function, viewed as vector after four iterations:
\begin{doublespace}
\noindent\(\(\left(f^{(1,0)}(f(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))),g(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))) \right.\\
\left(f^{(1,0)}(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))) \left(\left(g^{(1,0)}(x,y)+i g^{(0,1)}(x,y)\right) f^{(0,1)}(f(x,y),g(x,y))+\left(f^{(1,0)}(x,y)+i
f^{(0,1)}(x,y)\right) f^{(1,0)}(f(x,y),g(x,y))\right)+\right.\\
\left.f^{(0,1)}(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))) \left(\left(f^{(1,0)}(x,y)+i f^{(0,1)}(x,y)\right) g^{(1,0)}(f(x,y),g(x,y))+\left(g^{(1,0)}(x,y)+i
g^{(0,1)}(x,y)\right) g^{(0,1)}(f(x,y),g(x,y))\right)\right)+\left.f^{(0,1)}\right(f(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))),\\
g(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))) \left(g^{(0,1)}(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))) \left(\left(f^{(1,0)}(x,y)+i f^{(0,1)}(x,y)\right) g^{(1,0)}(f(x,y),g(x,y))+\left(g^{(1,0)}(x,y)+i
g^{(0,1)}(x,y)\right) g^{(0,1)}(f(x,y),g(x,y))\right)+\right.\\
\left.\left.\left(\left(g^{(1,0)}(x,y)+i g^{(0,1)}(x,y)\right) f^{(0,1)}(f(x,y),g(x,y))+\left(f^{(1,0)}(x,y)+i f^{(0,1)}(x,y)\right) f^{(1,0)}(f(x,y),g(x,y))\right)
g^{(1,0)}(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))\right)\right) \\
\left(f'(f(f(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))),g(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))))+i g'(f(f(f(f(x,y),g(x,y)),g(f(x,y),g(x,y))),g(f(f(x,y),g(x,y)),g(f(x,y),g(x,y)))))\right)\)\)
\end{doublespace}