I wanted to make the counter for a theorem displayed as capital roman numerals (I, II, III), but none of these attempts worked
\newtheorem{test}[\Roman{counter}]{Theorem}
\newtheorem{test}[Roman]{Theorem}
Is there a way to do this?
[Tex/LaTex] Set theorem counter to be Roman
counterstheorems
Related Solutions
Try
\renewcommand\thetheorem{\arabic{section}.\arabic{theorem}}
If you have a single named theorem, the easiest way is
\usepackage{amsthm}
\newtheorem*{HBT}{Hairy Ball Theorem}
so that
\begin{HBT}
There is no nonvanishing continuous tangent vector field on
even dimensional $n$-spheres.
\end{HBT}
will produce what you want.
If you have several named theorems, then a strategy similar to what you found will work:
\newtheorem*{namedthm*}{\thistheoremname}
\newcommand{\thistheoremname}{} % initialization
\newenvironment{namedthm}[1]
{\renewcommand{\thistheoremname}{#1}\begin{namedthm*}}
{\end{namedthm*}}
and the input will be
\begin{namedthm}{Hairy Ball Theorem}
There is no nonvanishing continuous tangent vector field on
even dimensional $n$-spheres.
\end{namedthm}
You can also give the attribution in the usual way:
\begin{namedthm}{Hairy Ball Theorem}[Brouwer]
There is no nonvanishing continuous tangent vector field on
even dimensional $n$-spheres.
\end{namedthm}
Complete example; choose your preferred strategy.
\documentclass{article}
\usepackage{amsthm}
\newtheorem*{HBT}{Hairy Ball Theorem}
\newtheorem*{namedthm*}{\thistheoremname}
\newcommand{\thistheoremname}{} % initialization
\newenvironment{namedthm}[1]
{\renewcommand{\thistheoremname}{#1}\begin{namedthm*}}
{\end{namedthm*}}
\begin{document}
\begin{HBT}
There is no nonvanishing continuous tangent vector field on
even dimensional $n$-spheres.
\end{HBT}
\begin{namedthm}{Hairy Ball Theorem}
There is no nonvanishing continuous tangent vector field on
even dimensional $n$-spheres.
\end{namedthm}
\begin{namedthm}{Hairy Ball Theorem}[Brouwer]
There is no nonvanishing continuous tangent vector field on
even dimensional $n$-spheres.
\end{namedthm}
\end{document}
Best Answer
Simply use:
Defining a new theorem environment
testdefines a new countertest. The optional argument, such as you used, says the ‘test’ environment shares the counter of another theorem-like environment.