Definition:Weight of Topological Space/Definition 1
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Definition
Let $T$ be a topological space.
Let $\mathbb B$ be the set of all bases of $T$.
The weight of $T$ is defined as:
- $\ds \map w T := \bigcap_{\BB \mathop \in \mathbb B} \card \BB$
where $\card \BB$ denotes the cardinality of $\BB$.
This article, or a section of it, needs explaining. In particular: what is the meaning of the intersection of a set of cardinalities? Does not seem to make sense. Would have expected it to be more like the cardinality of the intersection. Can this be checked? You can help $\mathsf{Pr} \infty \mathsf{fWiki}$ by explaining it. To discuss this page in more detail, feel free to use the talk page. When this work has been completed, you may remove this instance of {{Explain}} from the code. |
Also see
Sources
- Mizar article WAYBEL23:def 5