X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Fnlibrary%2Fnat%2Fnat.ma;h=e9d32973bdb02a10caba88490cd84603209feee4;hb=e880d6eab5e1700f4a625ddcd7d0fa8f0cce2dcc;hp=eed1efd1c83a907ed4c247e65d1a2ab9608fcd2a;hpb=2b98af47f4359ca20b42e52285c7ff4a3bd12f02;p=helm.git

diff --git a/helm/software/matita/nlibrary/nat/nat.ma b/helm/software/matita/nlibrary/nat/nat.ma
index eed1efd1c..e9d32973b 100644
--- a/helm/software/matita/nlibrary/nat/nat.ma
+++ b/helm/software/matita/nlibrary/nat/nat.ma
@@ -14,6 +14,7 @@
 
 include "hints_declaration.ma".
 include "logic/equality.ma".
+include "sets/setoids.ma".
 
 ninductive nat: Type[0] ≝
    O: nat