# [NTG-context] Bug in math: version

Hans Hagen j.hagen at xs4all.nl
Thu Feb 14 13:02:21 CET 2019

```On 2/13/2019 7:12 PM, Alan Braslau wrote:
> Not just the latest beta ... and indeed according to the TeXbook this should be a vertical double bar (\Vert), in math mode.
>
> I wish to point out that | in text font (text mode) is different from | in math font (math mode). I noticed that Preview (on the mac) *fails* to render the math font \$|\$ whereas \| in text mode does get rendered in Preview or printed from Preview (my document used dejavu fonts). Other pdf renderers on the mac (acroread, mupdf, evince, ...) are OK. This is clearly a bug in Preview.
>
> How, other then \|, should one produce | in *text* mode?
does \textbar work?

-----------------------------------------------------------------