# How to type rectangle norm symbol in math?

How can I write the rectangular norm symbol in math-mode where the text in between is centered, as seen hereinafter?

• Welcome. Perhaps the discussion here link to might be useful? – Steve Hodgkinson May 11 '16 at 5:37
• Much attention, vertical closed rectangle norm. Thank you Steven Hodgkinson. Help! :) – Deisy Rodriguez May 11 '16 at 5:46
• Thank you Stefan Pinnow, for edit and write correctly my post question. – Deisy Rodriguez May 11 '16 at 5:52
• The STIX fonts have \talloblong and \bigtalloblong, but no extensible delimiter. Are you planning to use this symbol in various sizes? – egreg May 11 '16 at 6:26
• To voters: the suggested duplicate is wrong as it doesn't address in any way the problem at hand. – egreg May 11 '16 at 6:54

\newcommand*\recnrm[1]{\left[\!\left]#1\right[\!\right]}

It's a first step, that can be “tweaked” but the important part is that you use a command \recnrm{x} or \recnrm{\frac{A}{B}}. Then you can change the definition later.
• The way to say thanks in this site is upvoting if you think an answer is useful, and accepting the answer that most benefited you. In any case, if you want to tweak the “width” of the delimiters, I could add a version where \! is substituted by a defined \mspace{-0.2ex} with predefined widths. – Manuel May 11 '16 at 23:16