Equivalences generated by families of Borel sets
Equivalences generated by families of Borel sets
The equivalence relation on the reals generated by a family of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="normal alef Subscript alpha"> <mml:semantics> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mi mathvariant="normal">ℵ<!-- ℵ --></mml:mi> <mml:mi>α<!-- α --></mml:mi> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">{\aleph _\alpha }</mml:annotation> </mml:semantics> </mml:math> </inline-formula> Borel sets has either <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="less-than-or-slanted-equals normal alef …