Index: tests/properties.test
===================================================================
diff -u -rf34ac86da9500e115e9bbd5e638b055d64896925 -r71015d43732133b53eed552468a6e408d43415eb
--- tests/properties.test	(.../properties.test)	(revision f34ac86da9500e115e9bbd5e638b055d64896925)
+++ tests/properties.test	(.../properties.test)	(revision 71015d43732133b53eed552468a6e408d43415eb)
@@ -674,7 +674,28 @@
 
 }
 
+#
+# Tests for experimental "value add", "value assign" ...
+#
 
+nx::test case property-value-incremental {
+
+  nx::Object create o1 {
+    :object property -incremental {a a1}
+  }
+
+  ? {o1 a add x} {x a1}
+  ? {o1 a {a1}} {a1}
+  
+  nsf::configure debug 2
+  ? {o1 a value add x    } {x a1}
+  ? {o1 a value assign {a b c}} {a b c}
+  ? {o1 a value get      } {a b c}
+  ? {o1 a value add x    } {x a b c}
+  ? {o1 a value add z end} {x a b c z}
+}
+
+
 #####################################################################
 # tests with class object
 #####################################################################