Definition talk:Neighborhood Sub-Basis

It's very common to use $X$ for the underlying set of a topology, and $\mathcal S$ for a sub-basis. $\mathcal B$ is typically used for a basis. --Dfeuer (talk) 18:32, 11 February 2013 (UTC)

"Common", but neither "universal" nor "mandatory". Consistency within site is good, so I've been generally moving towards using $S$ rather than $X$. --prime mover (talk) 21:02, 11 February 2013 (UTC)