A theorem by Lebesgue, Hausdorff and Banach says the following (Kechris' Classical Descriptive Set Theory, p. 192):
Let $X$ be a separable metrizable space and $f: X \rightarrow \mathbb{R}$ be a $\boldsymbol{\Sigma}_2^0$-measurable function, then $f$ is the pointwise limit of a sequence of continuous functions.
The theorem can be extended to functions with codomain $\mathbb{R}^n$ for each $n\in\mathbb{N}$. My questions are:
- Does this theorem hold for functions with codomain $\mathbb{R}^\omega$?
- Is there a counterexample of a $\boldsymbol{\Sigma}_2^0$-measurable function $f:\mathbb{R}^\omega\rightarrow\mathbb{R}^\omega$ which is not pointwise limit of a sequence of continuous functions?
Thanks!