Add graph view of trees

1 files changed, 3 insertions, 2 deletions

diff --git a/mgr.tex b/mgr.tex
index 81ca956..2ff3176 100644
--- a/mgr.tex
+++ b/mgr.tex
@@ -204,8 +204,9 @@ The rest of our work is organized in the following way:
 
 We work with finite trees whose vertices are labeled with letters from a finite
 alphabet. More formally, given a finite alphabet $\Sigma$, for each $a \in
-\Sigma$, $a$ is a tree, and if $t_1, \ldots, t_k$ are trees, then
-$a(t_1, \ldots, t_k)$ is also a tree.
+\Sigma$, $a$ is a tree, and if $t_1, \ldots, t_k$ are trees, then $a(t_1,
+\ldots, t_k)$ is also a tree. A tree $T$ can then also be seen as an acyclic
+undirected graph with vertex set $V(T)$ and edge set $E(T)$.
 
 We use the standard notions of root, child, sibling, ancestor, descendant, etc.