# Redefine \big, \Big, etc. dimension locally [duplicate]

I'd like to redefine \big, \Big etc. commands to change their dimensions for single equations. E.g.

{\makeatletter\renewcommand{\big}{\bBigg@{2}}\makeatother%
$$\big(\frac{1}{2}\big)$$}\relax


For practical reasons I'd like to define, in the preamble, a command like this:



so to have something like:

{\mybig{2}%
$$\big(\frac{1}{2}\big)$$}\relax


But it doesn't work. Where am I wrong?

• @PhelypeOleinik, Yes it does! If you post an answer to my question I will accept it. – Gabriele Nicolardi Feb 3 at 17:36
• Sorry, the question got closed before I got to write an answer. But the answer in the linked duplicate describes exactly why your attempt didn't work (it's a fairly common mistake, I myself made it a few times ;-) – Phelype Oleinik Feb 3 at 17:55