diff --git a/mono/Contours/tests.txt b/mono/Contours/tests.txt
index 46dedf6..c4ac4e0 100644
--- a/mono/Contours/tests.txt
+++ b/mono/Contours/tests.txt
@@ -15,3 +15,27 @@
 		( (((0, 0), (200, 0), (200, 100), (100, 100), (100, 200), (0, 200))),
 	  	  (((200, 200), (200, 100), (300, 100), (300, 300), (100, 300), (100, 200))) )
 }
+{
+	name:
+		(Self touch)
+	a:
+		((( (100, 100), (200, 0), (400, 0), (400, 300), (0, 300), (0, 200),
+		    (100, 100), (100, 200), (200, 200), (200, 100) )))
+	b:
+		( (( (100, 0), (200, 0), (200, 300), (100, 300) )),
+		  (( (250, 100), (350, 100), (350, 200), (250, 200) )) )
+	add:
+		((( (100, 100), (100, 0), (400, 0), (400, 300), (0, 300), (0, 200) )))
+	subtract:
+		( ( ( (100, 100), (100, 300), (0, 300), (0, 200) ) ),
+		  ( ( (200, 0), (400, 0), (400, 300), (200, 300) ),
+		    ( (250, 100), (250, 200), (350, 200), (350, 100) ) ) )
+	intersection:
+		( (( (100, 100), (200, 0), (200, 100) )),
+		  (( (100, 200), (200, 200), (200, 300), (100, 300) )),
+		  (( (250, 100), (350, 100), (350, 200), (250, 200) )) )
+	xor:
+		( ( ( (100, 0), (200, 0), (100, 100) ) ),
+		  ( ( (100, 100), (200, 100), (200, 0), (400, 0), (400, 300), (200, 300), (200, 200), (100, 200), (100, 300), (0, 300), (0, 200) ),
+		    ( (250, 100), (250, 200), (350, 200), (350, 100) ) ) )
+}