# How to change the font style in theorem environment?

I have a constant defined by

\newcommand{\Lip}{\textrm{Lip}}


or

\def\Lip{\text{Lip}}


I use this constant in equations. But in the theorem environment, it appears in italic style. Does anyone know how to make it appear the same as it being put outside of theorem environment?

Thank you very much!

if you are using amsmath (which you may be, since you are using \text) it would be better to use \DeclareMathOperator{\Lip}{Lip}. then it will always be in an upright font.
\newcommand{\Lip}{\ensuremath{\mathrm{Lip}}}

\usepackage{xspace}% To avoid adding a forced space after a command: '\Lip\ '