$\textbf{Basis}$
Let $X$ be a topological space. A set $\frak{B}$ of open sets is called a basis for the topology if every open set is a union of sets in $\frak{B}$.
$\textbf{Basis}$
Let $X$ be a topological space. A set $\frak{B}$ of open sets is called a basis for the topology if every open set is a union of sets in $\frak{B}$.
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𝐁𝐚𝐬𝐢𝐬
Let 𝑋 be a topological space. A set 𝔅 of open sets is called a basis for the topology if every open set is a union of sets in 𝔅.