On the closure of Baire classes under transfinite convergences
Tamás Mátrai · Fundamenta Mathematicae · 2004
Let $X$ be a Polish space and $Y$ be a separable metric space. For a fixed $\xi <\omega_{1}$, consider a family $f_{\alpha}\colon\, X \to Y~( \alpha<\omega_{1})$ of Baire-$\xi $ functions. Answering a question of Tomasz Natkaniec, we show that if for a