Thanks for the replies. Several have pointed out that the unique portions of map1 and map2 are simple functions that operate on scalars and are easily composable. However, this is not true of the actual problem I'm working on. I chose a toy example so I could describe it briefly. Unfortunately, it's misleadingly simple (rather obviously so, in retrospect).

I guess I'll just add that it's essential that all of these be mapping functions (i.e. they take a functional argument that they call back over some range, passing a value computed using that range).