I want two things: 1. to be able to use \cref
across different files and 2. to display certain environments (just the theorems for example) from an external file.
What I mean by (2) is the following. Suppose I have theorems in a file called external.tex
. Suppose I'm working in main.tex
. I want all of the theorems from external.tex
to be pasted into main.tex
without having to rewrite them.
Here is my code for (1):
external.tex:
\documentclass{article}
\usepackage{amsmath,cleveref}
\newtheorem{lem}{Lemma}
\begin{document}
\begin{lem}\label{mylemma}
blah blah blah
\end{lem}
\end{document}
main.tex:
\documentclass{article}
\usepackage{cleveref}
\usepackage{xr}
\externaldocument[ext:]{external}
\begin{document}
using \cref{ext:mylemma}
\end{document}
When I use \ref{ext:mylemma}
, it works. It just displays the number 1. When I use \cref{ext:mylemma}
, I get "?? 1". How do I fix this?