Set of symbols
Alphabet
Deduction system
Theory
Zermelo-Fraenkel set theory
Set
Binary cartesian set product
Binary relation
Binary endorelation
Preordering relation
Partial ordering relation
Partially ordered set
Closed interval
Closed real interval
Open real interval
Open real unit interval
Formulation 0
Let $P = (\mathbb{R}, {<})$ be the D1101: Strictly ordered set of real numbers.
The open real unit interval is the D11: Set \begin{equation} (0, 1) := \{ x \in \mathbb{R} : 0 < x < 1 \} \end{equation}