▾ Set of symbols
▾ Alphabet
▾ Deduction system
▾ Theory
▾ Zermelo-Fraenkel set theory
▾ Set
▾ Subset
▾ Power set
▾ Hyperpower set sequence
▾ Hyperpower set
▾ Hypersubset
▾ Subset algebra
▾ Subset structure
Topological space
Formulation 0
An D548: Ordered pair $T = (X, \mathcal{T})$ is a topological space if and only if
(1) $X$ is a D11: Set
(2) $\mathcal{T}$ is a D86: Topology on $X$
Child definitions
» D52: Closed map
» D1945: Closure point
» D55: Continuous map
» D1110: Discrete topological space
» D249: F-sigma set
» D248: G-delta set
» D465: Hausdorff topological space
» D457: Isolated point
» D785: Kolmogorov topological space
» D93: Neighbourhood
» D57: Open map
» D97: Open set
» D519: Set interior