Enumitem and multiple columns modules: bad mojo.

[Rudi Gaelzer]

I've seen a lot of reports in this list about the interaction of the enumited 
module with other latex classes (such as powerdot) or other modules, most of 
them regarding the Enumerate-Resume option.

Well, now I add my own.  I elaborate several exercise lists for my classes.  
Usually, the problems are printed in 2 columns, but eventually I need to 
switch to single column for a while and then resume the 2 columns.
Enumerate-Resume only works with the sequence 
1 column --> 2 columns
With the reverse (2 columns --> 1 column), the counter is always reset.  See 
the 2 first attached examples.

According to the tests I performed, the counter will only follow the correct 
sequence if I use the "series=" and "resume=" options.  However, if I blindly 
enter the Enumerate Option (with Alt+A 1) inside an Multiple Columns inset, an 
error message about a missing number will occur.  Exporting the text to latex, 
I noticed that the reason is because the enumitem option will be copied as a 
\begin{multicols} option (see mul_col_enumited3-lyx_output.tex).

The only workaround I found was entering manually the number of columns before 
(re)starting the list.  The attached mul_col_enumitem7.lyx file is the version 
that works as it should.

Perhaps there's a bug in any of the modules?
-- 
Rudi Gaelzer
Institute of Physics
Federal University of Rio Grande do Sul
BRAZIL
Registered linux user # 153741

mul_col_enumitem.lyx
Description: application/lyx

mul_col_enumitem2.lyx
Description: application/lyx

%% LyX 2.1.3 created this file.  For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[english]{article}
\usepackage{lmodern}
\renewcommand{\sfdefault}{lmss}
\renewcommand{\ttdefault}{lmtt}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}
\usepackage[a4paper]{geometry}
\geometry{verbose,tmargin=1in,bmargin=1in,lmargin=1in,rmargin=0.8in}
\usepackage{color}
\usepackage{babel}
\usepackage{multicol}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage[unicode=true,pdfusetitle,
 bookmarks=true,bookmarksnumbered=false,bookmarksopen=false,
 breaklinks=false,pdfborder={0 0 0},backref=false,colorlinks=true]
 {hyperref}
\hypersetup{
 linkcolor=blue, citecolor=blue}
\usepackage{breakurl}

\makeatletter
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands.
\usepackage{enumitem}		% customizable list environments
\newlength{\lyxlabelwidth}      % auxiliary length 

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
\usepackage{blindtext}
\usepackage{lipsum}

\makeatother

\begin{document}
\begin{center}
\textbf{\large{}One column first, then 2 columns, then 1 column again
(with series option)}
\par\end{center}{\large \par}

Notice how ``resume=test'' is printed, although the list is correctly
enumerated.

\noindent \rule[0.5ex]{1\columnwidth}{1pt}
\begin{enumerate}[series=test]
\item \blindtext
\item \lipsum[1]
\end{enumerate}
\begin{multicols}{resume=test}
\begin{enumerate}[resume=test]
\item \lipsum[2]
\item \blindtext\end{enumerate}
\end{multicols}

\begin{enumerate}[resume=test]
\item \lipsum[3]
\item \lipsum[4]\end{enumerate}

\end{document}

mul_col_enumitem7.lyx
Description: application/lyx