The points on a line can be put into a one-to-one correspondence with the real numbers.
Cantor-Dedekind Axiom
See also
Cardinal Number, Continuum Hypothesis, Dedekind CutExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Cantor-Dedekind Axiom." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Cantor-DedekindAxiom.html