Math and science::Analysis::Tao::05. The real numbers
Cut property for real numbers
Cut property for real numbers
If \( A \) and \( B \) are nonempty, disjoint sets with \( A \cup B = \mathbb{R} \) and \( a < b \) for all \( a \in A \) and \( a < b \), then there exists a [...] such [...].
This a Dekekind cut and Dedekind completeness.
The cut property expresses the idea that sets of reals always have a boundary which is itself a real.