# Problem with separation between items and numeration

I'm trying to generate a list with sublists using russian letter with no separation between the items. This is my MWE:

\documentclass[14pt,a4paper]{extarticle} %,twoside Usado en latex-ssau-gost-style-master
\RequirePackage[T2A]{fontenc}
\RequirePackage[utf8]{inputenc}
\RequirePackage[russian]{babel}
\usepackage{enumitem}
\makeatletter
\makeatother
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
\begin{enumerate}[label=\asbuk*),ref=\asbuk*,noitemsep]
\item Геометрические характеристики:
\begin{enumerate}[noitemsep]
\item $S$ - площадь крыла;\\
\end{enumerate}
\item Атмосферные характеристики:
\begin{enumerate}[noitemsep]
\item $\rho$ - плотность воздуха;\\
\item $a$ - скорость звука;\\
\end{enumerate}
\item Лётные характеристики:
\begin{enumerate}[noitemsep]
\item $H$ - высота полёта;\\
\item $V_{max}$ - максимальная скорость полёта;\\
\item $m$ - взлётная масса.
\end{enumerate}
\end{enumerate}
\end{document}

Should look like:

But this is what I get:

• This is a solution for a single list. I would like to declare this in the preamble- It is possible? Also I still have the separation. Jun 14, 2020 at 10:52
• I mean, the other way around. I do not want double spacing, instead I need to reduced it like in you first comment. I'm getting the second image, that is the problem. Jun 14, 2020 at 12:38
• As I said, with your code I get no extra separation. Do you get it with that code? Jun 14, 2020 at 12:41
• Yes, I also checked again right now in order to realize if I made a mistake when posting this question. Jun 14, 2020 at 12:47

Avoid \\ at the end of items. The command \\ has very rare usage outside of environments where it should be used to explicitly end lines, such as tabular or flushleft.

That's the cause of your issue.

You also probably want all your enumerate to follow the same style, so I suggest using \setlist.

I also fixed V_{max} to V_{\mathrm{max}}.

\documentclass[14pt,a4paper]{extarticle} %,twoside Usado en latex-ssau-gost-style-master
\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[russian]{babel}
\usepackage{enumitem}
\makeatletter
\makeatother

\setlist[enumerate]{noitemsep}
\setlist[enumerate,1]{label=\asbuk*)}
\setlist[enumerate,2]{label=\arabic*)}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}

\begin{enumerate}
\item Геометрические характеристики:
\begin{enumerate}
\item $S$ - площадь крыла;
\end{enumerate}
\item Атмосферные характеристики:
\begin{enumerate}
\item $\rho$ - плотность воздуха;
\item $a$ - скорость звука;
\end{enumerate}
\item Лётные характеристики:
\begin{enumerate}
\item $H$ - высота полёта;
\item $V_{\mathrm{max}}$ - максимальная скорость полёта;
\item $m$ - взлётная масса.
\end{enumerate}
\end{enumerate}

\end{document}

• Thats what Im talking about, from now I'll try to avoid the use '\\' in the those envirinment, that recommendation also apply to 'equation' environments? Jun 14, 2020 at 13:02