Well-quasi-ordering Aronszajn lines
We show that, assuming PFA, the class of all Aronszajn lines is well-quasi-ordered by embeddability.
Some remarks on non-special coherent Aronszajn trees
A countable dense homogeneous set of reals of size ℵ₁
We prove there is a countable dense homogeneous subspace of ℝ of size ℵ₁. The proof involves an absoluteness argument using an extension of the logic obtained by adding predicates for Borel sets.
Page 1