It's actually very easy to see what is happening with g and f in this example. I think the part that is pretty opaque to non-FPers is why you would want to do

It's actually very easy to see what is happening with g and f in this example. I think the part that is pretty opaque to non-FPers is why you would want to do that. Until something clicks, it is hard to see why this construct is anything beyond a very convoluted way of calculating 3 to the fourth power.