diff --git a/tree.md b/tree.md
new file mode 100644
index 000000000..5873e3744
--- /dev/null
+++ b/tree.md
@@ -0,0 +1,9 @@
+# Tree
+
+- [[pull]] [[trees]]
+
+
+[//begin]: # "Autogenerated link references for markdown compatibility"
+[pull]: pull "Pull"
+[trees]: trees "Trees"
+[//end]: # "Autogenerated link references"
\ No newline at end of file
diff --git a/trees.md b/trees.md
index 9ad448970..7f2f60544 100644
--- a/trees.md
+++ b/trees.md
@@ -1,6 +1,8 @@
 # Trees
 
-- [[pull]] [[graph]]
+- [[pull]] [[tree]]
+- [[pull]] a form of [[graph]]
+  - https://twitter.com/flancian/status/1355504964181889024
 - [[pull]] [[inosculation]]