How can I retrieve the default style of enumerate environment?

When I use nested enumerate environment it gave this style:

1.

(1)

(1)

I want to know, how to restore the default style?

I put the whole code in case one of the used packages are the cause.

\documentclass[a4paper, 14pt,oneside,authoryear]{extreport}
\usepackage[LFE,LAE]{fontenc}
\usepackage[cp1256,utf8]{inputenc}
\usepackage[ arabic ,english]{babel}
\usepackage[T1]{fontenc}
\usepackage{microtype}
\renewcommand{\familydefault}{\rmdefault}
\renewcommand*\rmdefault{ptm}
\usepackage{ccfonts}
\renewcommand*{\familydefault}{\rmdefault}
\renewcommand*\rmdefault{pplx}
\usepackage{enumerate}
\usepackage{calc}
\usepackage{setspace}

\begin{document}
\begin{enumerate}
\item Validation.
\item Static.
\item Dynamic.
\begin{enumerate}
\item Linear.
\item Non-Linear.
\end{enumerate}
\end{enumerate}
\end{document}

• This is not standard. Without a M.W.E., I'm afraid we can't help… – Bernard Nov 15 '16 at 10:34
• @Bernard - The problem is almost solved by Ambika, but I don't like to do that for every time I use enumerate, so is there any way to restet the enumerate to its default settings? – Muhammad Abdulrasool Nov 15 '16 at 11:19
• What I need to know is the code that produces this style. We can do almost anything we want with enumitem, but If I don't know how you obtained this result, what can I do? – Bernard Nov 15 '16 at 11:27
• @Bernard- I edit the question and add the M.W.E . – Muhammad Abdulrasool Nov 16 '16 at 8:57

The problem is linked to the arabic option of babel. I solved it (at least for the english part of the text) replacing the enumerate package with enumitem and setting the labels for the different levels of enumerate (up to level 3) in the preamble:

\documentclass[a4paper, 14pt,oneside,authoryear]{extreport}
\usepackage[LFE,LAE]{fontenc}%
\usepackage[utf8]{inputenc}%cp1256,
\usepackage[arabic , main = english]{babel}%
\usepackage[T1]{fontenc}
\usepackage{microtype}
\renewcommand{\familydefault}{\rmdefault}
\renewcommand*\rmdefault{ptm}
\usepackage{ccfonts}
\renewcommand*\rmdefault{pplx}
\usepackage{enumitem}
\setlist[enumerate, 1] {label = \arabic*.} %
\setlist[enumerate, 2] {label = (\alph*)} %
\setlist[enumerate, 3] {label = (\roman*)} %
\usepackage{calc}
\usepackage{setspace}

\begin{document}

\begin{enumerate}
\item Validation.
\item Static.
\item Dynamic.
\begin{enumerate}
\item Linear.
\item Non-Linear.
\end{enumerate}
\end{enumerate}

\end{document}


One solution, is trying to redefine to its original style with a customization as follows (by specifying the style needed as an option):

\documentclass{article}
\usepackage{enumerate}
\begin{document}
\begin{enumerate}[1.]
\item First level
\begin{enumerate}[(a)]
\item Second level
\begin{enumerate}[i.]
\item Third level
\begin{enumerate}[A.]
\item Fourth level
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{document}


Output:

• That is possible, can you define it at the beginning of the documents? i.e. resetting the environment of enumerate . – Muhammad Abdulrasool Nov 15 '16 at 11:13