Index: library/nx/nx.tcl
===================================================================
diff -u -r489b8b8e5f1ce1522121dcee270f18396c380071 -r2cca652c92b1933dd1b27f002a4c4886730f34f1
--- library/nx/nx.tcl	(.../nx.tcl)	(revision 489b8b8e5f1ce1522121dcee270f18396c380071)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision 2cca652c92b1933dd1b27f002a4c4886730f34f1)
@@ -1322,7 +1322,7 @@
 
   createBootstrapVariableSlots ::nx::RelationSlot {
     {accessor true}
-    {multiplicity 1..n}
+    {multiplicity 0..n}
   }
 
   RelationSlot protected method init {} {