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In mathematics, specifically in the field of topology, a topological space is said to be a door space if every subset is open or closed (or both). The term comes from the introductory topology mnemonic that "a subset is not like a door: it can be open, closed, both, or neither".
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door space displaystyle topology every open point closed accumulation set points subset discrete spaces isolated exactly neither also mathematics one
| Subject | Predicate | Object | Confidence | Src |
|---|---|---|---|---|
| Door space | is a | door space | 0.90 | text |
| Door space | related to Properties and examples | Every | 0.60 | section |
| Door space | related to Properties and examples | T0 | 0.60 | section |
| Door space | related to Properties and examples | So | 0.60 | section |
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