Vovk M. I.
Ukr. Mat. Zh. - 2004. - 56, № 4. - pp. 573–576
We prove that a Borel separately $Fσ$-measurable function $f: X \times Y → R$ on the product of Polish spaces is a function of the first Baire class on the complement $X × Y \backslash M$ of a certain projectively meager set $M ⊂ X × Y$.