added edge

tikz/graph-content-and-structure/graph-content-and-structure.tex

@@ -32,6 +32,7 @@
     \draw[edge] (h) edge (e);
     \draw[edge] (e) edge (z);
     \draw[edge] (i) edge (y);
+    \draw[edge] (y) edge (d);
 
     \draw [dashed] (-0.3,-0.3) rectangle (2.3,2.3);
     \draw [dashed] (2.5,2.3) rectangle (5, -0.3);