Aronszajn line

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An Aronszajn line is a linear ordering of cardinality \aleph_1 which contains no subset order-isomorphic to

Unlike Suslin lines, the existence of Aronszajn lines is provable using the standard axioms of set theory. A linear ordering is an Aronszajn line if and only if it is the lexicographical ordering of some Aronszajn tree.[1]

[edit] References

  1. ^ Funk, W.; Lutzer, D. (2005). "Lexicographically ordered trees". Topology and it Applications 152: 275–300. doi:10.1016/j.topol.2004.10.011.