Real Analysis: Is n-binary digit expansion of a number in [0,1] measurable?
If I have a function where and is the n-binary digit expansion of , how can I show that is measurable?
The full question I'm looking at asks to show that
I know that when we have a sequence of measurable functions, their sum will be measurable, and dividing a measurable function by n will still leave it measurable as well. Finally, when dealing with a sequence of measurable functions than their will also be measurable.
I have most of the puzzle figured out, but have never dealt with n-binary digits before. If I can just show that this expansion is measurable, everything else will fall into place.
My textbook tells me that if a sequence of functions converges, then it's limit will be measurable. Doesn't that apply in this case, since the n-binary digit expansion is converging to some point in [0,1]?