# Why does cleveref assign this wrong label?

I have a tex file

\documentclass[11pt]{amsart}
\usepackage{amssymb,enumitem,mathtools,fullpage,microtype}
\numberwithin{equation}{section}
\newtheorem{theorem}{Theorem}[section]
\theoremstyle{definition}
\newtheorem{assumption}[theorem]{Assumption}
\usepackage[hypertexnames=false]{hyperref}
\hypersetup{
filecolor=blue,
urlcolor=red,
citecolor=magenta
}
\usepackage{amsmath}
\usepackage{autonum}
\def\RR{\mathbb R}
\def\TT{\mathbb T}

\begin{document}
\setlist{font=\normalfont}
\section{Introduction}

\begin{assumption} \label{main_assmpt1}
There exist constants $C>0, \alpha \in (0, 1), \beta \in (0, 1)$ such that for $t \in \TT$ and $x, y \in \RR^d$:
\begin{enumerate}[label=(A\arabic*)]
\item $\nu$ has a density $\ell_\nu \in C^\alpha_b (\RR^d)$.
\item $a_t$ is invertible.
\end{enumerate}
\end{assumption}

\begin{theorem}
Let \cref{main_assmpt1} hold.
\begin{enumerate}
\item \cite[Theorem 2.1]{mckean1966class} ...
\end{enumerate}
\end{theorem}

\begin{thebibliography}{10}
\bibitem{mckean1966class}
Henry~P McKean~Jr.
\newblock A class of markov processes associated with nonlinear parabolic
equations.
\newblock {\em Proceedings of the National Academy of Sciences},
56(6):1907--1911, 1966.
\end{thebibliography}
\end{document}


The output is

I expect that it should be Let Assumption 1.1 hold rather than Let Theorem 1.1 hold. Could you explain why such behavior appears and how to solve it? Thank you so much for your help!

Theorem-like environments should be done after loading cleveref.

\documentclass[11pt]{amsart}
\usepackage{amssymb,enumitem,mathtools,fullpage,microtype}
\usepackage[hypertexnames=false]{hyperref}
\hypersetup{
filecolor=blue,
urlcolor=red,
citecolor=magenta
}
\usepackage{autonum}

\numberwithin{equation}{section}
\newtheorem{theorem}{Theorem}[section]
\theoremstyle{definition}
\newtheorem{assumption}[theorem]{Assumption}

\newcommand{\RR}{\mathbb{R}}
\newcommand{\TT}{\mathbb{T}}

\setlist{font=\normalfont}

\begin{document}

\section{Introduction}

\begin{assumption} \label{main_assmpt1}
There exist constants $C>0, \alpha \in (0, 1), \beta \in (0, 1)$ such that for $t \in \TT$ and $x, y \in \RR^d$:
\begin{enumerate}[label=(A\arabic*)]
\item $\nu$ has a density $\ell_\nu \in C^\alpha_b (\RR^d)$.
\item $a_t$ is invertible.
\end{enumerate}
\end{assumption}

\begin{theorem}
Let \cref{main_assmpt1} hold.
\begin{enumerate}
\item \cite[Theorem 2.1]{mckean1966class} ...
\end{enumerate}
\end{theorem}

\begin{thebibliography}{10}
\bibitem{mckean1966class}
Henry~P McKean~Jr.
\newblock A class of markov processes associated with nonlinear parabolic
equations.
\newblock {\em Proceedings of the National Academy of Sciences},
56(6):1907--1911, 1966.
\end{thebibliography}
\end{document}


Aside: don't use \def. And the correct syntax is \mathbb{R}. Also \setlist should go in the preamble.

See also Why does cleveref change theorem style unexpectedly? if you plan to use amsbook.

• Thank you so much for your help! Commented May 3 at 8:19