# How to remove the punctuation mark in a single newtheorem environment

I know how to do this globally, by including the:

\newtheoremstyle{dotless}{}{}{\itshape}{}{\bfseries}{}{ }{}
\theoremstyle{dotless}


commands. Is there any way to do this locally, for an individual environment?

You can define punctuation with a macro \punct which can be used to change of symbol coming after theorem head

\documentclass{article}
\usepackage{amsthm}
\usepackage{lipsum}

\def\punct{}

\newtheoremstyle{dotless}{3pt}{3pt}{\itshape}{}{\bfseries}{\punct}{.5em}{}
\theoremstyle{dotless}
\newtheorem{thm}{Theorem}

\begin{document}

\begin{thm}
\lipsum[2]
\end{thm}

\bigskip

\def\punct{.}

\begin{thm}
\lipsum[2]
\end{thm}

\bigskip

\def\punct{}

\begin{thm}
\lipsum[2]
\end{thm}

\end{document}