New posts in Borel Sets

Prove that $f$ is one-to-one on $B$ and $f^{-1}:Y\to B$ is Borel.

Question on Borel Measurable Functions and Borel Sigma Algebras.

Nontrivial Borel Sets

Does every uncountable Borel subset of $\mathbb R$ contains a perfect subset？

Constructing sigma algebras in countably many steps

If $X$ is a Borel set and $f$ has countably many discontinuities, prove that $f:X\rightarrow \mathbf{R}$ is Borel measurable.

A Question on Borel Measurable Functions

Why do we consider Borel sets instead of measurable sets?

Is "product" of Borel sigma algebras the Borel sigma algebra of the "product" of underlying topologies?

Nontrivial signed measure on Lebesgue measurable sets being trivial on Borel sets