A space with only Borel subsets
Saharon Shelah
Abstract
Miklos Laczkovich asked if there exists a Haussdorff (or even normal) space in which every subset is Borel yet it is not meager. The motivation of the last condition is that under MAkappa every subspace of the reals of cardinality kappa has the property that all subsets are Fsigma, however Martin's axiom also implies that these subsets are meager. Here we answer Laczkovich' question.
Create a lesson
Related papers
Logarithmic--exponential preparation in sharply o-minimal structures
Gal Binyamini, Oded Carmon, Dmitry Novikov
Stoic Logic and Natural Term Logic
Clarence Lewis Protin
From raw Solvability Complexity Index proofs to Weihrauch degrees
Christopher Sorg
Existence of bases implies the axiom of choice, a foundation-free proof
Gabriel Fernandes, Renan Maneli Mezabarba, Vinicius de Oliveira Rodrigues
Every countable meet-continuous lattice is Scott sober
Xiaoquan Xu, Wei Ji
A minimal type of Morley rank ω in a partial differential field
Piotr Kowalski