X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Flib%2Ftutorial%2Fchapter6.ma;h=a5355b5fa990fdea2185197ca25a45553ff5e5d9;hb=b5cb5cc7230870f757aadbe6b43ee146fe485a6d;hp=38fb54a0c3afa3a96be06c7d31a35285d3a651ff;hpb=38b251338be469c7bcd75cb9f243fad9ba8f0907;p=helm.git

diff --git a/matita/matita/lib/tutorial/chapter6.ma b/matita/matita/lib/tutorial/chapter6.ma
index 38fb54a0c..a5355b5fa 100644
--- a/matita/matita/lib/tutorial/chapter6.ma
+++ b/matita/matita/lib/tutorial/chapter6.ma
@@ -1,5 +1,6 @@
 
 include "tutorial/chapter5.ma".
+include "basics/core_notation/singl_1.ma".
 
 (*************************** Naive Set Theory *********************************)