src/HOL/Tools/Quotient/quotient_type.ML

       | Const (@{const_name part_equivp}, _) $ rel => 
         HOLogic.mk_conj (force_type_of_rel rel rty $ Bound 1 $ Bound 1, abs_fun_graph)
       | _ => error "unsupported equivalence theorem"
       )
     val def_term = Abs ("x", rty, Abs ("y", qty, Abs_body));
-    val qty_name = (fst o dest_Type) qty
-    val cr_rel_name = Binding.prefix_name "cr_" (Binding.qualified_name qty_name)  
+    val qty_name = (Binding.name o Long_Name.base_name o fst o dest_Type) qty
+    val cr_rel_name = Binding.prefix_name "cr_" qty_name
     val (fixed_def_term, lthy') = yield_singleton (Variable.importT_terms) def_term lthy
     val ((_, (_ , def_thm)), lthy'') =
       Local_Theory.define ((cr_rel_name, NoSyn), ((Thm.def_binding cr_rel_name, []), fixed_def_term)) lthy'
   in
     (def_thm, lthy'')

 fun setup_lifting_package gen_code quot3_thm equiv_thm lthy =
   let
     val (_ $ _ $ abs_fun $ _) = (HOLogic.dest_Trueprop o prop_of) quot3_thm
     val (T_def, lthy') = define_cr_rel equiv_thm abs_fun lthy
     val (rty, qty) = (dest_funT o fastype_of) abs_fun
-    val qty_name = (fst o dest_Type) qty
-    val quotient_thm_name = Binding.prefix_name "Quotient_" (Binding.qualified_name qty_name) 
+    val qty_name = (Binding.name o Long_Name.base_name o fst o dest_Type) qty
+    val quotient_thm_name = Binding.prefix_name "Quotient_" qty_name
     val (reflp_thm, quot_thm) = (case (HOLogic.dest_Trueprop o prop_of) equiv_thm of
       Const (@{const_name equivp}, _) $ _ =>
         (SOME (equiv_thm RS @{thm equivp_reflp2}),
          [quot3_thm, T_def, equiv_thm] MRSL @{thm Quotient3_to_Quotient_equivp})
       | Const (@{const_name part_equivp}, _) $ _ =>