tikz 代码永远运行而没有错误消息

Question

以下代码一直运行而不产生输出 - 在我使用多行标签之前它可以工作（未完成 - 底部元素的三行最简单的解决方案是什么？） - 并且无需绘制到节点的线条即可工作。绘制到节点的线条不会出现错误消息，但不会停止，也不会产生输出。

\documentclass[msmallroyalvopaper
    ]{memoir}
\usepackage{tikz}

\begin{document}

text 
\begin{tikzpicture}
% First, locate each of the nodes and name them
\node (top) at (0,1) {$\{\} = \top$};
\node  (left) at ((-1.5,0) {$\{\{A+\}=A$};
\node  (right) at (1.5,0){$\{A-\}=\lnot A $};
\node  (bottom) at (0,-1) {$\{A+,A-\} = \bot  =A \lor \lnot A$ }
%
%% Now draw the lines:
\draw [black,  thick, shorten <=-2pt, shorten >=-2pt] (top) -- (left);
\draw [black, thick, shorten <=-2pt, shorten >=-2pt] (top) -- (right);
\draw [black, thick, shorten <=-2pt, shorten >=-2pt] (left) -- (bottom);
\draw [black, thick, shorten <=-2pt, shorten >=-2pt] (right) -- (bottom);
\end{tikzpicture}
The multiple applications of a GIS can be summarized in three prototypical situations:

\end{document}