# Spacing of characters in a mathematical set, displayed inline in paragraph

I have a mathematical set notation that I want to display inline in a paragraph of text. However, when I write this, the output is not very beautiful:

$\{ (w_j,\dots,w_{j+n-1}) | 0 \leq j \leq k-1-n\}$


The curly braces look a bit too small, but it's bearable. What's worse is the spacing, I think: the curly braces are too close to the opening parenthesis on the left side and the "n" on the right side. The same with the pipe symbol in the middle: it's practically glued to the closing parenthesis and the "0".

Overall the tight spacing makes the definition difficult to read. So I wonder if there is a "better" way to write the above set, so that the output is more esthetically pleasing.

-
Very much related: Define pretty sets in LaTeX; esp., how to do the condition-separator? (possible duplicate?) –  Hendrik Vogt Mar 18 '11 at 17:30

Use \left\{ ... \mid ... \right\}. The spacing of the curly braces looks fine to me, but if you insist on more spacing you can add a \, between the \left\{ and the (. So, the complete equation becomes

$\left\{ (w_j,\dots,w_{j+n-1}) \mid 0 \leq j \leq k-1-n \right\}$


or, with the extra spacing

$\left\{\, (w_j,\dots,w_{j+n-1}) \mid 0 \leq j \leq k-1-n\,\right\}$

-
I'd like to add that in general \left...\right with in inline mathematics, should be used with extreme care, because they can easily become too large, and thus alter the line space –  daleif Mar 18 '11 at 15:50
I second that. Also, if you use \left\{ and \right\}, it makes sense to use \middle| instead of \mid, so that the vertical bar has the same size as the curly braces (note that \mid is not scalable). –  Michael Ummels Mar 18 '11 at 18:19
Ah, I did not know about the difference between \mid and \middle. I will revise my answer later this evening, explaining a bit more about delimiter sizing and stuff like that. Thanks for the additional info. –  Michel Mar 18 '11 at 18:43