I am using this template:
https://www.overleaf.com/latex/templates/springer-nature-latex-template/gsvvftmrppwq
my equation is:
\documentclass[pdflatex,sn-mathphys]{sn-jnl}% Math and Physical Sciences Reference Style
\jyear{2021}%
\theoremstyle{thmstyleone}%
\newtheorem{theorem}{Theorem}% meant for continuous numbers
\newtheorem{proposition}[theorem]{Proposition}%
\theoremstyle{thmstyletwo}%
\newtheorem{example}{Example}%
\newtheorem{remark}{Remark}%
\theoremstyle{thmstylethree}%
\newtheorem{definition}{Definition}%
\raggedbottom
\begin{document}
\begin{equation}
J(A, B)=\frac{|A \cap B|}{|A \cup B|}
\end{equation}
\bibliography{sn-bibliography}% common bib file
\end{document}
The same problem with:
\begin{equation}
dh_{i}=\left|h_{t l}-h_{i}\right|
\end{equation}
it gives an error and doesn't show |
in the equation.
Best Answer
For very mysterious reasons, the class loads
program.sty
, an obscure package that does several mysterious things and has essentially no documentation: one page with no examples; it tells to look intoprogram-demo.tex
, which is pretty uninformative as well.On the other hand, the scanty documentation for the package tells users to use
origbar
instead of|
.You should complain with the editors and the maintainers of the class, because forcing users to deal with this package is really awful of them. By the way, the class also loads
algpseudocode
, which is much better thanprogram
. What I find most irritating is that the package redefines\(
and\)
.Anyway, you can solve your problem by using
\lvert
and\rvert
which are actually better than the unadorned|
to denote absolute value or cardinality. LaTeX also provides\vert
as an alias.A more drastic step would be to undo the (wrong) settings made by
program.sty
.