# How to make new commands for function operations that don't italicize [duplicate]

I created new commands for Galois groups and Automorphism groups like so,

\newcommand{\Gal}[1]{\text{Gal}(#1)}
\newcommand{\Aut}[1]{\text{Aut}(#1)}


I wanted to the text of Gal and Aut to be unitalicized and that works for normal math mode, but it italicizes in theorem environments. How can I keep it from italicizing in theorems and propositions?

An example of a function that does what I want would be the gcd function.

## marked as duplicate by Henri Menke, Community♦Jan 28 '18 at 2:36

I suppose you load amsmath or mathtools. This is the way:
\DeclareMathOperator{\Gal}{Gal}