--- a/bin/curvecalc	Sat Jun 08 08:21:24 2013 +0000
+++ b/bin/curvecalc	Sat Jun 08 08:22:39 2013 +0000
@@ -35,6 +35,7 @@
 from light9.curvecalc.output import Output
 from light9.gtkpyconsole import togglePyConsole
 from light9.rdfdb.syncedgraph import SyncedGraph
+from light9.rdfdb.patch import Patch
 from light9.editchoicegtk import EditChoice
 from light9.observable import Observable
 
@@ -157,13 +158,26 @@
             self.makeSubterm(newname, withCurve=wc)
         dialog.hide()
 
+    def currentSong(self):
+        with self.graph.currentState() as current:
+            return current.value(self.session, L9['currentSong'])
+
+    def songSubtermsContext(self):
+        return self.currentSong()
+
     def makeSubterm(self, newname, withCurve=False, expr=None):
         uri = L9['sub/%s' % newname]
-        if (uri, RDF.type, L9.Subterm) in self.graph:
-            raise SubtermExists("already have a subterm named %r" % newname)
-        self.graph.add((uri, RDF.type, L9.Subterm))
-        self.graph.add((uri, RDFS.label, Literal(newname)))
-        self.graph.add((self.song, L9['subterm'], uri))
+        with self.graph.currentState() as current:
+            if (uri, RDF.type, L9.Subterm) in current:
+                raise SubtermExists("already have a subterm named %r" % newname)
+
+        ctx = self.songSubtermsContext()
+        self.graph.patch(Patch(addQuads=[
+            (uri, RDF.type, L9.Subterm, ctx),
+            (uri, RDFS.label, Literal(newname), ctx),
+            (self.currentSong(), L9['subterm'], uri, ctx),
+            ]))
+            
         if withCurve:
             self.curveset.new_curve(newname)
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/subterms	Sat Jun 08 08:22:39 2013 +0000
@@ -0,0 +1,8 @@
+
+
+song
+  -- :subterm -->
+    st
+       -- rdfs:label --> "chase 1"
+       -- :sub --> sub
+       -- :expression --> "curve1(t)"
\ No newline at end of file

--- a/light9/curvecalc/subtermview.py	Sat Jun 08 08:21:24 2013 +0000
+++ b/light9/curvecalc/subtermview.py	Sat Jun 08 08:22:39 2013 +0000
@@ -1,6 +1,6 @@
 import gtk, logging
 from louie import dispatcher
-from rdflib import RDF, RDFS, Literal
+from rdflib import URIRef
 from light9 import Submaster
 from light9.namespaces import L9
 from light9.curvecalc.subterm import Subterm, Subexpr
@@ -58,6 +58,7 @@
         self.exprView = sev.box
 
 def add_one_subterm(graph, subUri, curveset, subterms, master, expr=None, show=False):
+    assert isinstance(subUri, URIRef), subUri
     subname = graph.label(subUri)
     log.info("%s's label is %s" % (subUri, subname))
     if not subname: # fake sub, like for a chase