diff --git a/src/compiler/GF/Command/Commands.hs b/src/compiler/GF/Command/Commands.hs
index ddb7763bf..30b8883ba 100644
--- a/src/compiler/GF/Command/Commands.hs
+++ b/src/compiler/GF/Command/Commands.hs
@@ -619,8 +619,8 @@ pgfCommands = Map.fromList [
          mapM_ putStrLn ss
          return void
        else do
-         let funs = not (isOpt "nofun" opts)
-         let cats = not (isOpt "nocat" opts)
+         let funs = isOpt "nofun" opts
+         let cats = isOpt "nocat" opts
          let grphs = map (graphvizAbstractTree pgf (graphvizDefaults{noFun=funs,noCat=cats})) es
          if isFlag "view" opts || isFlag "format" opts
            then do
diff --git a/src/runtime/c/pgf/pgf.cxx b/src/runtime/c/pgf/pgf.cxx
index 00c0ea815..3abb69374 100644
--- a/src/runtime/c/pgf/pgf.cxx
+++ b/src/runtime/c/pgf/pgf.cxx
@@ -2067,6 +2067,24 @@ void pgf_set_concrete_flag(PgfDB *db, PgfConcrRevision revision,
     } PGF_API_END
 }
 
+PGF_API PgfText *
+pgf_graphviz_abstract_tree(PgfDB *db, PgfRevision revision,
+                           PgfExpr expr, PgfMarshaller *m,
+                           PgfGraphvizOptions* opts,
+                           PgfExn *err)
+{
+    PGF_API_BEGIN {
+        DB_scope scope(db, READER_SCOPE);
+
+        ref<PgfPGF> pgf = PgfDB::revision2pgf(revision);
+
+        PgfAbstractGraphvizOutput out(&pgf->abstract, opts, m);
+        return out.generate_graphviz(expr);
+    } PGF_API_END
+
+    return NULL;
+}
+
 PGF_API PgfText *
 pgf_graphviz_parse_tree(PgfDB *db, PgfConcrRevision revision,
                         PgfExpr expr, PgfMarshaller *m,
diff --git a/src/runtime/c/pgf/printer.cxx b/src/runtime/c/pgf/printer.cxx
index fbec41f32..014192b67 100644
--- a/src/runtime/c/pgf/printer.cxx
+++ b/src/runtime/c/pgf/printer.cxx
@@ -447,6 +447,20 @@ void PgfPrinter::parg(ref<PgfDTyp> ty, ref<PgfPArg> parg)
     puts(")");
 }
 
+void PgfPrinter::bindings(size_t n_vars)
+{
+    bool first = true;
+    PgfPrintContext *context = ctxt;
+    while (context != NULL && n_vars > 0) {
+        if (!first) {
+            puts(",");
+            first = false;
+        }
+        efun(&context->name);
+        context = context->next;
+    }
+}
+
 void PgfPrinter::lvar(size_t var)
 {
     char vars[] = "ijklmnopqr";
diff --git a/src/runtime/c/pgf/printer.h b/src/runtime/c/pgf/printer.h
index 4cfdf0b81..6e2978c70 100644
--- a/src/runtime/c/pgf/printer.h
+++ b/src/runtime/c/pgf/printer.h
@@ -18,14 +18,6 @@ class PGF_INTERNAL_DECL PgfPrinter : public PgfUnmarshaller {
     // of lambda expressions is finished.
     void flush_lambdas();
 
-    // Push a new variable in the printing context. If the name
-    // collides with an existing variable, the variable is renamed
-    // by adding a number.
-    void push_variable(PgfText *name);
-
-    // Pop the last variable name from the context.
-    void pop_variable();
-
     // The current operator priority
     int prio;
 
@@ -39,6 +31,14 @@ public:
     PgfPrinter(PgfPrintContext *context, int priority,
                PgfMarshaller *marshaller);
 
+    // Push a new variable in the printing context. If the name
+    // collides with an existing variable, the variable is renamed
+    // by adding a number.
+    void push_variable(PgfText *name);
+
+    // Pop the last variable name from the context.
+    void pop_variable();
+
     void puts(PgfText *s);
     void puts(const char *s);
 
@@ -72,6 +72,8 @@ public:
                          PgfText *cat,
                          size_t n_exprs, PgfExpr *exprs);
     virtual void free_ref(object x);
+
+    void bindings(size_t n_vars);
 };
 
 #endif
diff --git a/src/runtime/haskell/PGF2.hsc b/src/runtime/haskell/PGF2.hsc
index ef98989bf..031075eef 100644
--- a/src/runtime/haskell/PGF2.hsc
+++ b/src/runtime/haskell/PGF2.hsc
@@ -881,7 +881,14 @@ withGraphvizOptions opts f =
 
 -- | Renders an abstract syntax tree in a Graphviz format.
 graphvizAbstractTree :: PGF -> GraphvizOptions -> Expr -> String
-graphvizAbstractTree p opts e = error "TODO: graphvizAbstractTree"
+graphvizAbstractTree p opts e =
+  unsafePerformIO $
+  withForeignPtr (a_revision p) $ \c_revision ->
+  bracket (newStablePtr e) freeStablePtr $ \c_e ->
+  withForeignPtr marshaller $ \m ->
+  withGraphvizOptions opts $ \c_opts ->
+  bracket (withPgfExn "graphvizAbstractTree" (pgf_graphviz_abstract_tree (a_db p) c_revision c_e m c_opts)) free $ \c_text ->
+    peekText c_text
 
 graphvizParseTree :: Concr -> GraphvizOptions -> Expr -> String
 graphvizParseTree c opts e =
diff --git a/src/runtime/haskell/PGF2/FFI.hsc b/src/runtime/haskell/PGF2/FFI.hsc
index 47cee9485..44bf8ba80 100644
--- a/src/runtime/haskell/PGF2/FFI.hsc
+++ b/src/runtime/haskell/PGF2/FFI.hsc
@@ -227,6 +227,8 @@ foreign import ccall pgf_get_concrete_flag :: Ptr PgfDB -> Ptr Concr -> Ptr PgfT
 
 foreign import ccall pgf_set_concrete_flag :: Ptr PgfDB -> Ptr Concr -> Ptr PgfText -> StablePtr Literal -> Ptr PgfMarshaller -> Ptr PgfExn -> IO ()
 
+foreign import ccall pgf_graphviz_abstract_tree :: Ptr PgfDB -> Ptr PGF -> StablePtr Expr -> Ptr PgfMarshaller -> Ptr PgfGraphvizOptions -> Ptr PgfExn -> IO (Ptr PgfText)
+
 foreign import ccall pgf_graphviz_parse_tree :: Ptr PgfDB -> Ptr Concr -> StablePtr Expr -> Ptr PgfMarshaller -> Ptr PgfGraphvizOptions -> Ptr PgfExn -> IO (Ptr PgfText)