diff --git a/lib-nested-core/src/repr_tree/context.rs b/lib-nested-core/src/repr_tree/context.rs
index b592ae0..e7cad72 100644
--- a/lib-nested-core/src/repr_tree/context.rs
+++ b/lib-nested-core/src/repr_tree/context.rs
@@ -1,9 +1,15 @@
 use {
-    r3vi::{view::{OuterViewPort, singleton::*}, buffer::{singleton::*}},
-    laddertypes::{TypeDict, TypeTerm, TypeID, MorphismType, MorphismBase, Morphism},
     crate::{
-        repr_tree::{ReprTree, ReprTreeExt, GenericReprTreeMorphism},
-        edit_tree::EditTree
+        edit_tree::EditTree,
+        repr_tree::{GenericReprTreeMorphism, ReprTree, ReprTreeExt},
+    },
+    laddertypes::{
+        parser::ParseLadderType, sugar::SugaredTypeTerm, unparser::UnparseLadderType,
+        BimapTypeDict, Morphism, MorphismBase, MorphismType, TypeDict, TypeID, TypeTerm,
+    },
+    r3vi::{
+        buffer::singleton::*,
+        view::{singleton::*, OuterViewPort},
     },
     std::{
         collections::HashMap,
@@ -24,7 +30,7 @@ pub static TYPEID_vec : TypeID = TypeID::Fun(4);
 #[derive(Clone)]
 pub struct Context {
     /// assigns a name to every type
-    pub type_dict: Arc<RwLock<TypeDict>>,
+    pub type_dict: Arc<RwLock<BimapTypeDict>>,
 
     pub morphisms: laddertypes::morphism::MorphismBase< GenericReprTreeMorphism >,
 
@@ -53,12 +59,12 @@ impl Context {
             type_dict: match parent.as_ref() {
                 Some(p) => p.read().unwrap().type_dict.clone(),
                 None => {
-                    let mut dict = TypeDict::new();
-                    assert_eq!( TYPEID_edittree, dict.add_typename("EditTree".into()) );
-                    assert_eq!( TYPEID_char, dict.add_typename("Char".into()) );
-                    assert_eq!( TYPEID_u64, dict.add_typename("machine.UInt64".into()) );
-                    assert_eq!( TYPEID_list, dict.add_typename("List".into()) );
-                    assert_eq!( TYPEID_vec, dict.add_typename("Vec".into()) );
+                    let mut dict = BimapTypeDict::new();
+                    assert_eq!(TYPEID_edittree, dict.add_typename("EditTree".into()));
+                    assert_eq!(TYPEID_char, dict.add_typename("Char".into()));
+                    assert_eq!(TYPEID_u64, dict.add_typename("machine.UInt64".into()));
+                    assert_eq!(TYPEID_list, dict.add_typename("List".into()));
+                    assert_eq!(TYPEID_vec, dict.add_typename("Vec".into()));
 
                     Arc::new(RwLock::new(dict))
                 }