diff --git a/demo/digraph.lgf b/demo/digraph.lgf
new file mode 100644
--- /dev/null
+++ b/demo/digraph.lgf
@@ -0,0 +1,29 @@
+@nodes
+label
+0
+1
+2
+3
+4
+5
+6
+7
+@arcs
+		label capacity
+0 	1 	0  	  16
+0 	2 	1 	  12
+0 	3 	2 	  20
+1 	2 	3 	  10
+1 	4 	4 	  10
+1 	5 	5 	  13
+2 	3 	6 	  10
+2 	4 	7 	  8
+2 	6 	8 	  8
+5 	3 	9 	  20
+3 	6 	10 	  25
+4 	7 	11 	  15
+5 	7 	12 	  15
+6 	7 	13 	  18
+@attributes
+source 0
+target 7