命令 \par 不起作用？

Question

我有这个代码：

\documentclass[8pt,a4paper]{article}
\newcounter{conto}
\setcounter{conto}{\time}
\usepackage{lmodern}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{amssymb}
\usepackage{ dsfont }
\begin{document}
\section{Prove 1}
\begin{flushleft}
Def.: let be \( \mathfrak{m}: x \to \mathcal{P}( \mathcal{P}(x))\), \( \mathfrak{m} \) is topology on \( x \) if \par
1) \( x \neq \emptyset \) \par
2) \( \forall a \in x (x \in \mathfrak{m}(a) )\) \par
3) \(\forall a \in x (\forall t \in \mathfrak{m}(a)( a \in t))\) \par
4) \( \forall a \in x(\forall r,s \in \mathfrak{m}(a)((r \cap s) \in \mathfrak{m}(a) ))\) \par
5) \( \forall a \in x( \forall t \in \mathfrak{m}(x)(\exists r \in \mathfrak{m}(x)(\forall y \in r(t \in \mathfrak{m}(y)))))\) \par
6) \( \forall a \in x(\forall t \in \mathfrak{m}(x)(\forall r \subseteq x(t \subseteq r \to r \in \mathfrak{m}(x)))) \)
\section{Prove 2}
\end{flushleft}
\end{document}

pdf内容如下：

因为该命令\par不起作用？

Answer 1

\documentclass[preview,border=12pt]{standalone}% change it back to your own documentclass

\usepackage{enumerate}

\usepackage{amssymb}

\begin{document}
\section{Prove 1}

Def.: let be \( \mathfrak{m}: x \to \mathcal{P}( \mathcal{P}(x))\), \( \mathfrak{m} \) is topology on \( x \) if 
\begin{enumerate}[1)]
\item \( x \neq \emptyset \) 
\item \( \forall a \in x (x \in \mathfrak{m}(a) )\) 
\item \(\forall a \in x (\forall t \in \mathfrak{m}(a)( a \in t))\)
\item \( \forall a \in x(\forall r,s \in \mathfrak{m}(a)((r \cap s) \in \mathfrak{m}(a) ))\) 
\item \( \forall a \in x( \forall t \in \mathfrak{m}(x)(\exists r \in \mathfrak{m}(x)(\forall y \in r(t \in \mathfrak{m}(y)))))\) 
\item \( \forall a \in x(\forall t \in \mathfrak{m}(x)(\forall r \subseteq x(t \subseteq r \to r \in \mathfrak{m}(x)))) \)
\end{enumerate}
\end{document}