--- a/graphics.sty	Thu Oct 29 00:25:20 2020 +0000
+++ b/graphics.sty	Fri Oct 30 01:45:03 2020 +0000
@@ -22,3 +22,30 @@
 \bgroup\begin{minipage}{#1}\raggedright{}}
 {\end{minipage}\egroup;%
 \end{tikzpicture}\bigskip}
+
+
+%%% for trees
+%% http://anorien.csc.warwick.ac.uk/mirrors/CTAN/graphics/pgf/contrib/forest/forest.pdf
+
+\newcommand\grid[1]{%
+\begin{tikzpicture}[baseline=(char.base)]
+  \path[use as bounding box]
+    (0,0) rectangle (1em,1em);
+  \draw[red!50, fill=red!20]
+    (0,0) rectangle (1em,1em);
+  \node[inner sep=1pt,anchor=base west]
+    (char) at (0em,\gridraiseamount) {#1};
+\end{tikzpicture}}
+\newcommand\gridraiseamount{0.12em}
+
+\makeatletter
+\newcommand\Grid[1]{%
+  \@tfor\z:=#1\do{\grid{\z}}}
+\makeatother	
+
+\newcommand\Vspace[1][.3em]{%
+  \mbox{\kern.06em\vrule height.3ex}%
+  \vbox{\hrule width#1}%
+  \hbox{\vrule height.3ex}}
+
+\def\VS{\Vspace[0.6em]}
\ No newline at end of file