We show that, assuming PFA, the class of all Aronszajn lines is well-quasi-ordered by embeddability.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm213-3-1, author = {Carlos Martinez-Ranero}, title = {Well-quasi-ordering Aronszajn lines}, journal = {Fundamenta Mathematicae}, volume = {215}, year = {2011}, pages = {197-211}, zbl = {1235.03072}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm213-3-1} }
Carlos Martinez-Ranero. Well-quasi-ordering Aronszajn lines. Fundamenta Mathematicae, Tome 215 (2011) pp. 197-211. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm213-3-1/