我正在尝试使用以下包打印出一棵树：
\usepackage{epic} % required by ecltree and fancybox packages
\usepackage{ecltree} % to draw the GP trees
\usepackage{fancybox} % required by \Ovalbox
\setlength{\GapWidth}{1em}
\thicklines \drawwith{\dottedline{2}}
\newcommand{\gpbox}[1]{\Ovalbox{#1\rule[-.7ex]{0ex}{2.7ex}}}
这是我的实际代码：
deep structure, which does not increase the complexity of the problem as we will recursively apply reductions all the same.
\begin{center}
\begin{minipage}[!ht]{1cm}
\begin{bundle}{\gpbox{L}}\chunk{\begin{bundle}{\gpbox{L}}\chunk{\begin{bundle}{\gpbox{L}}\chunk{\begin{bundle}{\gpbox{P}}\chunk{\gpbox{2}}\chunk{\gpbox{1}}\end{bundle}}\end{bundle}}\end{bundle}}\end{bundle}
\end{minipage}
\end{center}
Moreover, many techniques are available for simplifying $\lambda$-trees. As explained in Section \ref{secReduction}, $\alpha$-conversion could be used to rename nodes in $\lambda$-trees and $\eta$-conversion could be used to take out redundant parts.
树出现了，但是，如果我将文本放在树之前或之后，就会出现很大的间隙，如下图所示：
。
我也尝试过删除，\begin{center} \end{center}但没什么用。更改后的样子如下：
有什么办法可以让它变得像一张具有正常间隙的正常图片吗？