\import{topology/topological-space.tex} \import{order/order.tex} \section{Order Topology} \begin{abbreviation}\label{open_interval} $z \in \oointervalof{x}{y}$ iff $x \mathrel{R} y$ and $x \mathrel{R} z$ and $z \mathrel{R} y$. %$\oointervalof{x}{y}{X} = \{ z \mid x \in X, y \in X, z \in X x \mathrel{R} y \wedge x \mathrel{R} z \wedge z \mathrel{R} y\}$. \end{abbreviation} \begin{struct}\label{order_topology} A ordertopology space $X$ is a onesorted structure equipped with \begin{enumerate} \item $<$ \end{enumerate} such that \begin{enumerate} \item \label{order_topology_1} $<$ is a strict order on $X$ \item \label{order_topology_2} \item \label{order_topology_3} \item \label{order_topology_4} \item \label{order_topology} \item \label{order_topology} \item \label{order_topology} \end{enumerate} \end{struct} %\begin{definition}\label{order_topology} % $X$ has the order topology iff for all $x,y \in X$ $X$ has a strict order $R$ and $\oointervalof{x}{y}{X} \in \opens[X]$ and $X$ is a topological space. % %$O$ is the order Topology on $X$ iff for all $x,y \in X$ $X$ has a strict order $R$ and $(x,y) \in O$ and $O$ is . %\end{definition}