Souslin's Hypothesis

Every dense linear order complete set without endpoints having at most $\omega$ disjoint intervals is order isomorphic to the Continuum of Real Numbers, where $\omega$ is the set of Natural Numbers.

References

Iyanaga, S. and Kawada, Y. (Eds.). ``Souslin's Hypothesis.'' §35E.4 in in Encyclopedic Dictionary of Mathematics. Cambridge, MA: MIT Press, p. 137, 1980.