The lattice of sets of natural numbers is rich Posted on 2021/09/10 by Carl Robitaille The lattice of sets of natural numbers is rich The lattice of sets of natural numbers is rich. It is universal for all countable orders; it has uncountable chains isomorphic to the reals; it has uncountable antichains; yet it is highly homogeneous. https://t.co/wXdJzRSNCQ— Joel David Hamkins (@JDHamkins) August 13, 2021