Definition:Weight of Topological Space/Definition 1

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:
 * $\displaystyle \map w T := \bigcap_{\BB \mathop \in \mathbb B} \card \BB$

where $\card \BB$ denotes the cardinality of $\BB$.

Also see

 * Equivalence of Definitions of Weight of Topological Space