diff --git a/backend/cn/baseTypes.ml b/backend/cn/baseTypes.ml
index 8f0a1d321..9e4798bee 100644
--- a/backend/cn/baseTypes.ml
+++ b/backend/cn/baseTypes.ml
@@ -10,7 +10,7 @@ type basetype =
   | CType
   | Struct of Sym.t
   | Datatype of Sym.t
-  | Record of member_types
+  | Record of (Id.t * basetype) list
   | Map of basetype * basetype
   | List of basetype
   | Tuple of basetype list
@@ -18,9 +18,6 @@ type basetype =
   (* | Option of basetype *)
 [@@deriving eq, ord]
 
-and member_types =
-  (Id.t * basetype) list
-
 
 type t = basetype
 
@@ -31,10 +28,10 @@ let compare = compare_basetype
 
 type datatype_info = {
   dt_constrs: Sym.t list;
-  dt_all_params: member_types;
+  dt_all_params: (Id.t * basetype) list;
 }
 type constr_info = {
-  c_params: member_types;
+  c_params: (Id.t * basetype) list;
   c_datatype_tag: Sym.t
 }
 
diff --git a/backend/cn/solver.ml b/backend/cn/solver.ml
index f294ca2ae..4aaee8ce1 100644
--- a/backend/cn/solver.ml
+++ b/backend/cn/solver.ml
@@ -143,8 +143,8 @@ module Translate = struct
     | StructFunc of { tag : Sym.t }
     | CompFunc of { bts : BT.t list; i : int }
     | TupleFunc of  { bts : BT.t list }
-    | RecordFunc of { mbts : BT.member_types }
-    | RecordMemberFunc of { mbts : BT.member_types; member : Id.t }
+    | RecordFunc of { mbts : (Id.t * basetype) list }
+    | RecordMemberFunc of { mbts : (Id.t * basetype) list; member : Id.t }
     | DefaultFunc of { bt : BT.t }
     | DatatypeConsFunc of { nm: Sym.t }
     | DatatypeConsRecogFunc of { nm: Sym.t }
diff --git a/backend/cn/surfaceBaseTypes.ml b/backend/cn/surfaceBaseTypes.ml
index 271b6483d..c3afbd38e 100644
--- a/backend/cn/surfaceBaseTypes.ml
+++ b/backend/cn/surfaceBaseTypes.ml
@@ -12,7 +12,7 @@ type basetype =
   | Loc of Sctypes.t option
   | Struct of Sym.t
   | Datatype of Sym.t
-  | Record of member_types
+  | Record of (Id.t * basetype) list
   | Map of basetype * basetype
   | List of basetype
   | Tuple of basetype list
@@ -20,8 +20,6 @@ type basetype =
   (* | Option of basetype *)
 [@@deriving eq, ord]
 
-and member_types =
-  (Id.t * basetype) list
 
 
 type t = basetype
@@ -31,19 +29,6 @@ let equal = equal_basetype
 let compare = compare_basetype
 
 
-type datatype_info = {
-  dt_constrs: Sym.t list;
-  dt_all_params: member_types;
-}
-type constr_info = {
-  c_params: member_types;
-  c_datatype_tag: Sym.t
-}
-
-let cons_dom_rng info =
-  (Record info.c_params, Datatype info.c_datatype_tag)
-
-
 let rec pp = function
   | Unit -> !^"void"
   | Bool -> !^"bool"
diff --git a/backend/cn/typing.mli b/backend/cn/typing.mli
index 7c7ec1dbc..da3ec7826 100644
--- a/backend/cn/typing.mli
+++ b/backend/cn/typing.mli
@@ -100,7 +100,7 @@ val ensure_base_type: Locations.t -> expect:LogicalSorts.t -> LogicalSorts.t ->
 val make_return_record: 
     Locations.t ->
     string ->
-    BaseTypes.member_types ->
+    (Id.t * BaseTypes.t) list ->
     (IndexTerms.t * IndexTerms.t list) m
 
 val bind_logical_return: