If I show two graphs f(x) and g(x) where g(x) is a vertical translation of 3, I want them to write f(x) + 3 and be able to parse out the 3. So that should work fine with functionCall.
But if g(x) is say 3f(x) + 2, I want to parse out the 3 and the 2 from their entered expression. I can use that complicated CL that Mike Gleeson wrote here: Function Transformations in af(k(x-c))+d Form | Component Based Approach , but I was hoping to use a simpler pattern approach.