diff --git a/src/passes/10-interpreter/interpreter.ml b/src/passes/10-interpreter/interpreter.ml
index 43e78312a..77d30cb71 100644
--- a/src/passes/10-interpreter/interpreter.ml
+++ b/src/passes/10-interpreter/interpreter.ml
@@ -378,9 +378,6 @@ and eval : Ast_typed.expression -> env -> value result
     )
     | E_recursive {fun_name; fun_type=_; lambda} ->
       ok @@ V_Func_rec (fun_name, lambda.binder, lambda.result, env)
-    | E_look_up _ ->
-      let serr = Format.asprintf "Unsupported construct :\n %a\n" Ast_typed.PP.expression term in
-      simple_fail serr
 
 let dummy : Ast_typed.program -> string result =
   fun prg ->
diff --git a/src/passes/10-transpiler/transpiler.ml b/src/passes/10-transpiler/transpiler.ml
index b83e84bf6..b7935bbe4 100644
--- a/src/passes/10-transpiler/transpiler.ml
+++ b/src/passes/10-transpiler/transpiler.ml
@@ -234,7 +234,6 @@ and tree_of_sum : AST.type_expression -> (AST.constructor' * AST.type_expression
 and transpile_annotated_expression (ae:AST.expression) : expression result =
   let%bind tv = transpile_type ae.type_expression in
   let return ?(tv = tv) expr = ok @@ Combinators.Expression.make_tpl (expr, tv) in
-  let f = transpile_annotated_expression in
   let info =
     let title () = "translating expression" in
     let content () = Format.asprintf "%a" Location.pp ae.location in
@@ -439,10 +438,6 @@ and transpile_annotated_expression (ae:AST.expression) : expression result =
       let init = return @@ E_make_empty_big_map (src, dst) in
       List.fold_left aux init m
     )
-  | E_look_up dsi -> (
-      let%bind (ds', i') = bind_map_pair f dsi in
-      return @@ E_constant {cons_name=C_MAP_FIND_OPT;arguments=[i' ; ds']}
-    )
   | E_matching {matchee=expr; cases=m} -> (
       let%bind expr' = transpile_annotated_expression expr in
       match m with
diff --git a/src/passes/6-sugar_to_core/sugar_to_core.ml b/src/passes/6-sugar_to_core/sugar_to_core.ml
index e75b9c2ff..e7a3f20fc 100644
--- a/src/passes/6-sugar_to_core/sugar_to_core.ml
+++ b/src/passes/6-sugar_to_core/sugar_to_core.ml
@@ -127,8 +127,8 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind set = bind_map_list compile_expression set in
       return @@ O.E_set set 
     | I.E_look_up look_up ->
-      let%bind look_up = bind_map_pair compile_expression look_up in
-      return @@ O.E_look_up look_up
+      let%bind (path, index) = bind_map_pair compile_expression look_up in
+      return @@ O.E_constant {cons_name=C_MAP_FIND_OPT;arguments=[index;path]}
     | I.E_ascription {anno_expr; type_annotation} ->
       let%bind anno_expr = compile_expression anno_expr in
       let%bind type_annotation = idle_type_expression type_annotation in
diff --git a/src/passes/8-typer-new/typer.ml b/src/passes/8-typer-new/typer.ml
index f446c1076..94a1682bd 100644
--- a/src/passes/8-typer-new/typer.ml
+++ b/src/passes/8-typer-new/typer.ml
@@ -685,17 +685,6 @@ and type_expression : environment -> Solver.state -> ?tv_opt:O.type_expression -
     let wrapped = Wrap.application f'.type_expression args.type_expression in
     return_wrapped (E_application {lamb=f';args}) state'' wrapped
 
-  (* | E_look_up dsi ->
-   *   let%bind (ds, ind) = bind_map_pair (type_expression e) dsi in
-   *   let%bind (src, dst) = bind_map_or (get_t_map , get_t_big_map) ds.type_annotation in
-   *   let%bind _ = O.assert_type_value_eq (ind.type_annotation, src) in
-   *   return (E_look_up (ds , ind)) (t_option dst ()) *)
-
-  | E_look_up dsi ->
-    let aux' state' elt = type_expression e state' elt >>? swap in
-    let%bind (state'' , (ds , ind)) = bind_fold_map_pair aux' state dsi in
-    let wrapped = Wrap.look_up ds.type_expression ind.type_expression in
-    return_wrapped (E_look_up (ds , ind)) state'' wrapped
 
   (* Advanced *)
   (* | E_matching (ex, m) -> (
@@ -1076,9 +1065,6 @@ let rec untype_expression (e:O.expression) : (I.expression) result =
   | E_set lst ->
     let%bind lst' = bind_map_list untype_expression lst in
     return (e_set lst')
-  | E_look_up dsi ->
-    let%bind (a , b) = bind_map_pair untype_expression dsi in
-    return (e_look_up a b)
   | E_matching {matchee;cases} ->
     let%bind ae' = untype_expression matchee in
     let%bind m' = untype_matching untype_expression cases in
diff --git a/src/passes/8-typer-old/typer.ml b/src/passes/8-typer-old/typer.ml
index d26828230..2b6764dea 100644
--- a/src/passes/8-typer-old/typer.ml
+++ b/src/passes/8-typer-old/typer.ml
@@ -703,11 +703,6 @@ and type_expression' : environment -> ?tv_opt:O.type_expression -> I.expression
             lamb'.location
       in
       return (E_application {lamb=lamb'; args=args'}) tv
-  | E_look_up dsi ->
-      let%bind (ds, ind) = bind_map_pair (type_expression' e) dsi in
-      let%bind (src, dst) = bind_map_or (get_t_map , get_t_big_map) ds.type_expression in
-      let%bind _ = O.assert_type_expression_eq (ind.type_expression, src) in
-      return (E_look_up (ds , ind)) (t_option dst ())
   (* Advanced *)
   | E_matching {matchee;cases} -> (
       let%bind ex' = type_expression' e matchee in
@@ -882,9 +877,6 @@ let rec untype_expression (e:O.expression) : (I.expression) result =
   | E_set lst ->
       let%bind lst' = bind_map_list untype_expression lst in
       return (e_set lst')
-  | E_look_up dsi ->
-      let%bind (a , b) = bind_map_pair untype_expression dsi in
-      return (e_look_up a b)
   | E_matching {matchee;cases} ->
       let%bind ae' = untype_expression matchee in
       let%bind m' = untype_matching untype_expression cases in
diff --git a/src/passes/9-self_ast_typed/helpers.ml b/src/passes/9-self_ast_typed/helpers.ml
index 90a9fe9cc..658a05f31 100644
--- a/src/passes/9-self_ast_typed/helpers.ml
+++ b/src/passes/9-self_ast_typed/helpers.ml
@@ -16,9 +16,6 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
     let%bind res = bind_fold_list (bind_fold_pair self) init' lst in
     ok res
   )
-  | E_look_up ab ->
-      let%bind res = bind_fold_pair self init' ab in
-      ok res
   | E_application {lamb; args} -> (
       let ab = (lamb, args) in
       let%bind res = bind_fold_pair self init' ab in
@@ -109,10 +106,6 @@ let rec map_expression : mapper -> expression -> expression result = fun f e ->
     let%bind lst' = bind_map_list (bind_map_pair self) lst in
     return @@ E_big_map lst'
   )
-  | E_look_up ab -> (
-      let%bind ab' = bind_map_pair self ab in
-      return @@ E_look_up ab'
-    )
   | E_matching {matchee=e;cases} -> (
       let%bind e' = self e in
       let%bind cases' = map_cases f cases in
@@ -224,10 +217,6 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
     let%bind (res, lst') = bind_fold_map_list (bind_fold_map_pair self) init' lst in
     ok (res, return @@ E_big_map lst')
   )
-  | E_look_up ab -> (
-      let%bind (res, ab') = bind_fold_map_pair self init' ab in
-      ok (res, return @@ E_look_up ab')
-    )
   | E_matching {matchee=e;cases} -> (
       let%bind (res, e') = self init' e in
       let%bind (res,cases') = fold_map_cases f res cases in
diff --git a/src/passes/9-self_ast_typed/tail_recursion.ml b/src/passes/9-self_ast_typed/tail_recursion.ml
index 5e3953bc3..c95f10c06 100644
--- a/src/passes/9-self_ast_typed/tail_recursion.ml
+++ b/src/passes/9-self_ast_typed/tail_recursion.ml
@@ -67,10 +67,6 @@ let rec check_recursive_call : expression_variable -> bool -> expression -> unit
   | E_list el | E_set el ->
     let%bind _ = bind_map_list (check_recursive_call n false) el in
     ok ()
-  | E_look_up (e1,e2) ->
-    let%bind _ = check_recursive_call n false e1 in
-    let%bind _ = check_recursive_call n false e2 in
-    ok ()
 
 and check_recursive_call_in_matching = fun n final_path c ->
   match c with
diff --git a/src/stages/3-ast_core/PP.ml b/src/stages/3-ast_core/PP.ml
index 0d648065e..9673beef7 100644
--- a/src/stages/3-ast_core/PP.ml
+++ b/src/stages/3-ast_core/PP.ml
@@ -39,8 +39,6 @@ and expression_content ppf (ec : expression_content) =
       fprintf ppf "list[%a]" (list_sep_d expression) lst
   | E_set lst ->
       fprintf ppf "set[%a]" (list_sep_d expression) lst
-  | E_look_up (ds, ind) ->
-      fprintf ppf "(%a)[%a]" expression ds expression ind
   | E_lambda {binder; input_type; output_type; result} ->
       fprintf ppf "lambda (%a:%a) : %a return %a"
         expression_variable binder
diff --git a/src/stages/3-ast_core/combinators.ml b/src/stages/3-ast_core/combinators.ml
index 90d1cebd8..91a77d217 100644
--- a/src/stages/3-ast_core/combinators.ml
+++ b/src/stages/3-ast_core/combinators.ml
@@ -127,7 +127,6 @@ let e_annotation ?loc anno_expr ty = make_expr ?loc @@ E_ascription {anno_expr;
 let e_application ?loc a b = make_expr ?loc @@ E_application {lamb=a ; args=b}
 let e_binop ?loc name a b  = make_expr ?loc @@ E_constant {cons_name = name ; arguments = [a ; b]}
 let e_constant ?loc name lst = make_expr ?loc @@ E_constant {cons_name=name ; arguments = lst}
-let e_look_up ?loc x y = make_expr ?loc @@ E_look_up (x , y)
 let e_cond ?loc expr match_true match_false = e_matching expr ?loc (Match_bool {match_true; match_false})
 (*
 let e_assign ?loc a b c = location_wrap ?loc @@ E_assign (Var.of_name a , b , c) (* TODO handlethat*)
diff --git a/src/stages/3-ast_core/combinators.mli b/src/stages/3-ast_core/combinators.mli
index ae0aab1bd..a16a36600 100644
--- a/src/stages/3-ast_core/combinators.mli
+++ b/src/stages/3-ast_core/combinators.mli
@@ -89,7 +89,6 @@ val e_annotation : ?loc:Location.t -> expression -> type_expression -> expressio
 val e_application : ?loc:Location.t -> expression -> expression -> expression
 val e_binop    : ?loc:Location.t -> constant' -> expression -> expression -> expression
 val e_constant : ?loc:Location.t -> constant' -> expression list -> expression
-val e_look_up : ?loc:Location.t -> expression -> expression -> expression
 val ez_match_variant : ((string * string ) * 'a ) list -> ('a,unit) matching_content
 val e_matching_variant : ?loc:Location.t -> expression -> ((string * string) * expression) list -> expression
 
diff --git a/src/stages/3-ast_core/misc.ml b/src/stages/3-ast_core/misc.ml
index a09efa475..96a9f3750 100644
--- a/src/stages/3-ast_core/misc.ml
+++ b/src/stages/3-ast_core/misc.ml
@@ -183,8 +183,8 @@ let rec assert_value_eq (a, b: (expression * expression )) : unit result =
   | (E_variable _, _) | (E_lambda _, _)
   | (E_application _, _) | (E_let_in _, _)
   | (E_recursive _,_) | (E_record_accessor _, _)
-  | (E_look_up _, _) | (E_matching _, _)
-   -> simple_fail "comparing not a value"
+  | (E_matching _, _)
+  -> simple_fail "comparing not a value"
 
 let is_value_eq (a , b) = to_bool @@ assert_value_eq (a , b)
 
diff --git a/src/stages/3-ast_core/types.ml b/src/stages/3-ast_core/types.ml
index 81ba90fa2..4ad14d148 100644
--- a/src/stages/3-ast_core/types.ml
+++ b/src/stages/3-ast_core/types.ml
@@ -49,7 +49,6 @@ and expression_content =
   | E_big_map of (expression * expression) list (*move to operator *)
   | E_list of expression list
   | E_set of expression list
-  | E_look_up of (expression * expression)
   (* Advanced *)
   | E_ascription of ascription
 
diff --git a/src/stages/4-ast_typed/PP.ml b/src/stages/4-ast_typed/PP.ml
index ab655c80b..3fe4f02c8 100644
--- a/src/stages/4-ast_typed/PP.ml
+++ b/src/stages/4-ast_typed/PP.ml
@@ -40,8 +40,6 @@ and expression_content ppf (ec: expression_content) =
       fprintf ppf "list[%a]" (list_sep_d expression) lst
   | E_set lst ->
       fprintf ppf "set[%a]" (list_sep_d expression) lst
-  | E_look_up (ds, ind) ->
-      fprintf ppf "(%a)[%a]" expression ds expression ind
   | E_lambda {binder; result} ->
       fprintf ppf "lambda (%a) return %a" expression_variable binder
         expression result
diff --git a/src/stages/4-ast_typed/misc.ml b/src/stages/4-ast_typed/misc.ml
index 533520fe7..5def088a8 100644
--- a/src/stages/4-ast_typed/misc.ml
+++ b/src/stages/4-ast_typed/misc.ml
@@ -214,7 +214,6 @@ module Free_variables = struct
     | E_list lst -> unions @@ List.map self lst
     | E_set lst -> unions @@ List.map self lst
     | (E_map m | E_big_map m) -> unions @@ List.map self @@ List.concat @@ List.map (fun (a, b) -> [ a ; b ]) m
-    | E_look_up (a , b) -> unions @@ List.map self [ a ; b ]
     | E_matching {matchee; cases;_} -> union (self matchee) (matching_expression b cases)
     | E_let_in { let_binder; rhs; let_result; _} ->
       let b' = union (singleton let_binder) b in
@@ -534,7 +533,7 @@ let rec assert_value_eq (a, b: (expression*expression)) : unit result =
   | (E_literal _, _) | (E_variable _, _) | (E_application _, _)
   | (E_lambda _, _) | (E_let_in _, _) | (E_recursive _, _)
   | (E_record_accessor _, _) | (E_record_update _,_)
-  | (E_look_up _, _) | (E_matching _, _)
+  | (E_matching _, _)
   -> fail @@ error_uncomparable_values "can't compare sequences nor loops" a b
 
 let merge_annotation (a:type_expression option) (b:type_expression option) err : type_expression result =
diff --git a/src/stages/4-ast_typed/misc_smart.ml b/src/stages/4-ast_typed/misc_smart.ml
index 1d1110a1c..763bfa399 100644
--- a/src/stages/4-ast_typed/misc_smart.ml
+++ b/src/stages/4-ast_typed/misc_smart.ml
@@ -84,9 +84,6 @@ module Captured_variables = struct
     | (E_map m | E_big_map m) ->
       let%bind lst' = bind_map_list self @@ List.concat @@ List.map (fun (a, b) -> [ a ; b ]) m in
       ok @@ unions lst'
-    | E_look_up (a , b) ->
-      let%bind lst' = bind_map_list self [ a ; b ] in
-      ok @@ unions lst'
     | E_matching {matchee;cases;_} ->
       let%bind a' = self matchee in
       let%bind cs' = matching_expression b cases in
diff --git a/src/stages/4-ast_typed/types.ml b/src/stages/4-ast_typed/types.ml
index 5fbe79554..fa303e21c 100644
--- a/src/stages/4-ast_typed/types.ml
+++ b/src/stages/4-ast_typed/types.ml
@@ -55,7 +55,6 @@ and expression_content =
   | E_big_map of (expression * expression) list (*move to operator *)
   | E_list of expression list
   | E_set of expression list
-  | E_look_up of (expression * expression)
 
 and constant =
   { cons_name: constant'
diff --git a/src/stages/typesystem/misc.ml b/src/stages/typesystem/misc.ml
index affe9fd37..c74e9e8f1 100644
--- a/src/stages/typesystem/misc.ml
+++ b/src/stages/typesystem/misc.ml
@@ -210,10 +210,6 @@ module Substitution = struct
       | T.E_set             vals ->
         let%bind vals = bind_map_list (s_expression ~substs) vals in
         ok @@ T.E_set vals
-      | T.E_look_up         (val1, val2) ->
-        let%bind val1 = s_expression ~substs val1 in
-        let%bind val2 = s_expression ~substs val2 in
-        ok @@ T.E_look_up (val1 , val2)
       | T.E_matching   {matchee;cases} ->
         let%bind matchee = s_expression ~substs matchee in
         let%bind cases = s_matching_expr ~substs cases in