Topological spaces
A topology specifies which subsets are open.
Key knowledge
A topology on X contains ∅ and X and is closed under arbitrary unions and finite intersections. A subset is closed when its complement in X is open.
Conditions and scope
- Openness is relative to the selected topology.
- A metric is not required by this definition.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Section 1.1: topology axioms and inverse-image continuity; printed page 11, physical page 9.
2026-10-10 · Topology and closed-set definitions only.
Entry details
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- math-topological-spaces
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- university-reference.1
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- University reference