Use numbers in every level of enumeration?

Question

Is it possible to use only numbers on front of every item? Something like this:

1. ABC
2. DEF
   • abc
   • def
     • xyz

But only with numbers.

Answer 1

You can use the enumitem package to define a list like the one you want; the following example is taken from the package documentation:

\documentclass{article}
\usepackage{enumitem}

\newlist{legal}{enumerate}{10}
\setlist[legal]{label*=\arabic*.}

\begin{document}

\begin{legal}
  \item First item.
  \begin{legal}
    \item First subitem.
    \begin{legal}
      \item First subsubitem.
    \end{legal}
  \end{legal}
\end{legal}

\end{document}

Answer 2

You can use the enumerate package (although enumitem is far more flexible), or manage the list numbering yourself:

\documentclass{article}
\usepackage{enumerate}% http://ctan.org/pkg/enumerate
\begin{document}
\begin{enumerate}
  \item ABC
  \item DEF
  \begin{enumerate}[1.]
    \item abc
    \item def
    \begin{enumerate}[1.]
      \item uvw
      \item xyz
    \end{enumerate}
  \end{enumerate}
\end{enumerate}
\end{document}