Chains and antichains in Boolean algebras
Tom 163 / 2000
Fundamenta Mathematicae 163 (2000), 55-76
DOI: 10.4064/fm-163-1-55-76
Streszczenie
We give an affirmative answer to problem DJ from Fremlin's list [8] which asks whether $MA_{ω_1}$ implies that every uncountable Boolean algebra has an uncountable set of pairwise incomparable elements.
