% Copied from: https://ghost.tweakblogs.net/blog/720/requirement-list-in-latex.html

\newcommand{\reqitem}[1]{
    $R_{#1}$
}

\newcommand{\reqinit}{
    \newcounter{reqcountbackup}
    \newcounter{reqcount}
    \renewcommand{\thereqcount}{\reqitem{\arabic{reqcount}}}
}

\newcommand{\reqlist}[1]{
    \begin{list}{\thereqcount}{\usecounter{reqcount}}
        \setcounter{reqcount}{\value{reqcountbackup}}
        #1
        \setcounter{reqcountbackup}{\value{reqcount}}
    \end{list}
}