diff --git a/src/ast_simplified/PP.ml b/src/ast_simplified/PP.ml
index e136988d2..07277c664 100644
--- a/src/ast_simplified/PP.ml
+++ b/src/ast_simplified/PP.ml
@@ -24,6 +24,7 @@ let literal ppf (l:literal) = match l with
   | Literal_bool b -> fprintf ppf "%b" b
   | Literal_int n -> fprintf ppf "%d" n
   | Literal_nat n -> fprintf ppf "+%d" n
+  | Literal_timestamp n -> fprintf ppf "+%d" n
   | Literal_tez n -> fprintf ppf "%dtz" n
   | Literal_string s -> fprintf ppf "%S" s
   | Literal_bytes b -> fprintf ppf "0x%s" @@ Bytes.to_string @@ Bytes.escaped b
@@ -41,6 +42,7 @@ let rec expression ppf (e:expression) = match Location.unwrap e with
   | E_record m -> fprintf ppf "record[%a]" (smap_sep_d expression) m
   | E_map m -> fprintf ppf "map[%a]" (list_sep_d assoc_expression) m
   | E_list lst -> 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"
diff --git a/src/ast_simplified/combinators.ml b/src/ast_simplified/combinators.ml
index 690c9dfcb..5702dafc7 100644
--- a/src/ast_simplified/combinators.ml
+++ b/src/ast_simplified/combinators.ml
@@ -32,6 +32,7 @@ let ez_t_sum (lst:(string * type_expression) list) : type_expression =
 
 let t_function param result : type_expression = T_function (param, result)
 let t_map key value = (T_constant ("map", [key ; value]))
+let t_set key = (T_constant ("set", [key]))
 
 let make_name (s : string) : name = s
 
@@ -40,6 +41,7 @@ let e_literal ?loc l : expression = Location.wrap ?loc @@ E_literal l
 let e_unit ?loc () : expression = Location.wrap ?loc @@ E_literal (Literal_unit)
 let e_int ?loc n : expression = Location.wrap ?loc @@ E_literal (Literal_int n)
 let e_nat ?loc n : expression = Location.wrap ?loc @@ E_literal (Literal_nat n)
+let e_timestamp ?loc n : expression = Location.wrap ?loc @@ E_literal (Literal_timestamp n)
 let e_bool ?loc   b : expression = Location.wrap ?loc @@ E_literal (Literal_bool b)
 let e_string ?loc s : expression = Location.wrap ?loc @@ E_literal (Literal_string s)
 let e_address ?loc s : expression = Location.wrap ?loc @@ E_literal (Literal_address s)
@@ -51,6 +53,7 @@ let e_some ?loc s : expression = Location.wrap ?loc @@ E_constant ("SOME", [s])
 let e_none ?loc () : expression = Location.wrap ?loc @@ E_constant ("NONE", [])
 let e_map_add ?loc k v old : expression = Location.wrap ?loc @@ E_constant ("MAP_ADD" , [k ; v ; old])
 let e_map ?loc lst : expression = Location.wrap ?loc @@ E_map lst
+let e_set ?loc lst : expression = Location.wrap ?loc @@ E_set lst
 let e_list ?loc lst : expression = Location.wrap ?loc @@ E_list lst
 let e_pair ?loc a b : expression = Location.wrap ?loc @@ E_tuple [a; b]
 let e_constructor ?loc s a : expression = Location.wrap ?loc @@ E_constructor (s , a)
@@ -90,6 +93,8 @@ let e_typed_list ?loc lst t =
   e_annotation ?loc (e_list lst) (t_list t)
 
 let e_typed_map ?loc lst k v = e_annotation ?loc (e_map lst) (t_map k v)
+    
+let e_typed_set ?loc lst k = e_annotation ?loc (e_set lst) (t_set k)
 
 let e_lambda ?loc (binder : string)
     (input_type : type_expression option)
diff --git a/src/ast_simplified/misc.ml b/src/ast_simplified/misc.ml
index c857b8072..5cb679187 100644
--- a/src/ast_simplified/misc.ml
+++ b/src/ast_simplified/misc.ml
@@ -42,6 +42,9 @@ let assert_literal_eq (a, b : literal * literal) : unit result =
   | Literal_nat a, Literal_nat b when a = b -> ok ()
   | Literal_nat _, Literal_nat _ -> fail @@ different_literals "different nats" a b
   | Literal_nat _, _ -> fail @@ different_literals_because_different_types "nat vs non-nat" a b
+  | Literal_timestamp a, Literal_timestamp b when a = b -> ok ()
+  | Literal_timestamp _, Literal_timestamp _ -> fail @@ different_literals "different timestamps" a b
+  | Literal_timestamp _, _ -> fail @@ different_literals_because_different_types "timestamp vs non-timestamp" a b
   | Literal_tez a, Literal_tez b when a = b -> ok ()
   | Literal_tez _, Literal_tez _ -> fail @@ different_literals "different tezs" a b
   | Literal_tez _, _ -> fail @@ different_literals_because_different_types "tez vs non-tez" a b
@@ -59,7 +62,6 @@ let assert_literal_eq (a, b : literal * literal) : unit result =
   | Literal_operation _, Literal_operation _ -> fail @@ error_uncomparable_literals "can't compare operations" a b
   | Literal_operation _, _ -> fail @@ different_literals_because_different_types "operation vs non-operation" a b
 
-
 let rec assert_value_eq (a, b: (expression * expression )) : unit result =
   let error_content () =
     Format.asprintf "\n@[<v>- %a@;- %a]" PP.expression a PP.expression b
@@ -143,6 +145,19 @@ let rec assert_value_eq (a, b: (expression * expression )) : unit result =
     )
   | E_list _, _ ->
       simple_fail "comparing list with other stuff"
+
+  | E_set lsta, E_set lstb -> (
+      let lsta' = List.sort (compare) lsta in
+      let lstb' = List.sort (compare) lstb in
+      let%bind lst =
+        generic_try (simple_error "set of different lengths")
+          (fun () -> List.combine lsta' lstb') in
+      let%bind _all = bind_map_list assert_value_eq lst in
+      ok ()
+    )
+  | E_set _, _ ->
+      simple_fail "comparing set with other stuff"
+
   | (E_annotation (a , _) ,  _b') -> assert_value_eq (a , b)
   | (_a' , E_annotation (b , _)) -> assert_value_eq (a , b)
   | (E_variable _, _) | (E_lambda _, _)
diff --git a/src/ast_simplified/types.ml b/src/ast_simplified/types.ml
index 4693546b8..3eb0990cb 100644
--- a/src/ast_simplified/types.ml
+++ b/src/ast_simplified/types.ml
@@ -60,6 +60,7 @@ and expression' =
   (* Data Structures *)
   | E_map of (expr * expr) list
   | E_list of expr list
+  | E_set of expr list
   | E_look_up of (expr * expr)
   (* Matching *)
   | E_matching of (expr * matching_expr)
@@ -90,6 +91,7 @@ and literal =
   | Literal_string of string
   | Literal_bytes of bytes
   | Literal_address of string
+  | Literal_timestamp of int
   | Literal_operation of Memory_proto_alpha.Alpha_context.packed_internal_operation
 
 and 'a matching =
diff --git a/src/ast_typed/PP.ml b/src/ast_typed/PP.ml
index 4c2122fa8..3e8edf30c 100644
--- a/src/ast_typed/PP.ml
+++ b/src/ast_typed/PP.ml
@@ -43,6 +43,7 @@ and expression ppf (e:expression) : unit =
   | E_record m -> fprintf ppf "record[%a]" (smap_sep_d annotated_expression) m
   | E_map m -> fprintf ppf "map[@;  @[<v>%a@]@;]" (list_sep assoc_annotated_expression (tag ",@;")) m
   | E_list m -> fprintf ppf "list[@;  @[<v>%a@]@;]" (list_sep annotated_expression (tag ",@;")) m
+  | E_set m -> fprintf ppf "set[@;  @[<v>%a@]@;]" (list_sep annotated_expression (tag ",@;")) m
   | E_look_up (ds, i) -> fprintf ppf "(%a)[%a]" annotated_expression ds annotated_expression i
   | E_matching (ae, m) ->
       fprintf ppf "match %a with %a" annotated_expression ae (matching annotated_expression) m
@@ -68,6 +69,7 @@ and literal ppf (l:literal) : unit =
   | Literal_bool b -> fprintf ppf "%b" b
   | Literal_int n -> fprintf ppf "%d" n
   | Literal_nat n -> fprintf ppf "+%d" n
+  | Literal_timestamp n -> fprintf ppf "+%d" n
   | Literal_tez n -> fprintf ppf "%dtz" n
   | Literal_string s -> fprintf ppf "%s" s
   | Literal_bytes b -> fprintf ppf "0x%s" @@ Bytes.to_string @@ Bytes.escaped b
diff --git a/src/ast_typed/combinators.ml b/src/ast_typed/combinators.ml
index 5dc82ee9d..1b4a1926c 100644
--- a/src/ast_typed/combinators.ml
+++ b/src/ast_typed/combinators.ml
@@ -27,6 +27,7 @@ let t_unit ?s () : type_value = make_t (T_constant ("unit", [])) s
 let t_option o ?s () : type_value = make_t (T_constant ("option", [o])) s
 let t_tuple lst ?s () : type_value = make_t (T_tuple lst) s
 let t_list t ?s () : type_value = make_t (T_constant ("list", [t])) s
+let t_set t ?s () : type_value = make_t (T_constant ("set", [t])) s
 let t_contract t ?s () : type_value = make_t (T_constant ("contract", [t])) s
 let t_pair a b ?s () = t_tuple [a ; b] ?s ()
 
@@ -95,6 +96,10 @@ let get_t_list (t:type_value) : type_value result = match t.type_value' with
   | T_constant ("list", [o]) -> ok o
   | _ -> simple_fail "not a list"
 
+let get_t_set (t:type_value) : type_value result = match t.type_value' with
+  | T_constant ("set", [o]) -> ok o
+  | _ -> simple_fail "not a set"
+
 let get_t_key (t:type_value) : unit result = match t.type_value' with
   | T_constant ("key", []) -> ok ()
   | _ -> simple_fail "not a key"
diff --git a/src/ast_typed/misc.ml b/src/ast_typed/misc.ml
index 077f00c0a..091531789 100644
--- a/src/ast_typed/misc.ml
+++ b/src/ast_typed/misc.ml
@@ -155,6 +155,7 @@ module Free_variables = struct
     | E_record_accessor (a, _) -> self a
     | E_tuple_accessor (a, _) -> self a
     | E_list lst -> unions @@ List.map self lst
+    | E_set lst -> unions @@ List.map self lst
     | E_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 (a , cs) -> union (self a) (matching_expression b cs)
@@ -344,6 +345,9 @@ let assert_literal_eq (a, b : literal * literal) : unit result =
   | Literal_nat a, Literal_nat b when a = b -> ok ()
   | Literal_nat _, Literal_nat _ -> fail @@ different_literals "different nats" a b
   | Literal_nat _, _ -> fail @@ different_literals_because_different_types "nat vs non-nat" a b
+  | Literal_timestamp a, Literal_timestamp b when a = b -> ok ()
+  | Literal_timestamp _, Literal_timestamp _ -> fail @@ different_literals "different timestamps" a b
+  | Literal_timestamp _, _ -> fail @@ different_literals_because_different_types "timestamp vs non-timestamp" a b
   | Literal_tez a, Literal_tez b when a = b -> ok ()
   | Literal_tez _, Literal_tez _ -> fail @@ different_literals "different tezs" a b
   | Literal_tez _, _ -> fail @@ different_literals_because_different_types "tez vs non-tez" a b
@@ -443,6 +447,15 @@ let rec assert_value_eq (a, b: (value*value)) : unit result =
     )
   | E_list _, _ ->
       fail @@ different_values_because_different_types "list vs. non-list" a b
+  | E_set lsta, E_set lstb -> (
+      let%bind lst =
+        generic_try (different_size_values "sets of different lengths" a b)
+          (fun () -> List.combine lsta lstb) in
+      let%bind _all = bind_map_list assert_value_eq lst in
+      ok ()
+    )
+  | E_set _, _ ->
+      fail @@ different_values_because_different_types "set vs. non-set" a b
   | (E_literal _, _) | (E_variable _, _) | (E_application _, _)
   | (E_lambda _, _) | (E_let_in _, _) | (E_tuple_accessor _, _)
   | (E_record_accessor _, _)
diff --git a/src/ast_typed/misc_smart.ml b/src/ast_typed/misc_smart.ml
index 2c56ad89c..0d0e8cd02 100644
--- a/src/ast_typed/misc_smart.ml
+++ b/src/ast_typed/misc_smart.ml
@@ -77,6 +77,9 @@ module Captured_variables = struct
     | E_list lst ->
       let%bind lst' = bind_map_list self lst in
       ok @@ unions lst'
+    | E_set lst ->
+      let%bind lst' = bind_map_list self lst in
+      ok @@ unions lst'
     | E_map m ->
       let%bind lst' = bind_map_list self @@ List.concat @@ List.map (fun (a, b) -> [ a ; b ]) m in
       ok @@ unions lst'
diff --git a/src/ast_typed/types.ml b/src/ast_typed/types.ml
index a1bfd46d3..65524fde8 100644
--- a/src/ast_typed/types.ml
+++ b/src/ast_typed/types.ml
@@ -100,6 +100,7 @@ and expression =
   (* Data Structures *)
   | E_map of (ae * ae) list
   | E_list of ae list
+  | E_set of ae list
   | E_look_up of (ae * ae)
   (* Advanced *)
   | E_matching of (ae * matching_expr)
@@ -116,6 +117,7 @@ and literal =
   | Literal_bool of bool
   | Literal_int of int
   | Literal_nat of int
+  | Literal_timestamp of int
   | Literal_tez of int
   | Literal_string of string
   | Literal_bytes of bytes
diff --git a/src/compiler/compiler_program.ml b/src/compiler/compiler_program.ml
index ee6a1bab9..bae56f546 100644
--- a/src/compiler/compiler_program.ml
+++ b/src/compiler/compiler_program.ml
@@ -62,6 +62,7 @@ let rec translate_value (v:value) : michelson result = match v with
   | D_bool b -> ok @@ prim (if b then D_True else D_False)
   | D_int n -> ok @@ int (Z.of_int n)
   | D_nat n -> ok @@ int (Z.of_int n)
+  | D_timestamp n -> ok @@ int (Z.of_int n)
   | D_tez n -> ok @@ int (Z.of_int n)
   | D_string s -> ok @@ string s
   | D_bytes s -> ok @@ bytes (Tezos_stdlib.MBytes.of_bytes s)
@@ -226,14 +227,6 @@ and translate_expression ?(first=false) (expr:expression) (env:environment) : (m
       i_drop ;
       b' ;
     ]
-  (* | E_sequence_drop (a , b) ->
-   *   let%bind (a' , env_a) = translate_expression a env in
-   *   let%bind (b' , env_b) = translate_expression b env_a in
-   *   return ~end_env:env_b @@ seq [
-   *     a' ;
-   *     i_drop ;
-   *     b' ;
-   *   ] *)
   | E_constant(str, lst) ->
       let module L = Logger.Stateful() in
       let%bind lst' =
@@ -279,6 +272,9 @@ and translate_expression ?(first=false) (expr:expression) (env:environment) : (m
   | E_make_empty_list t ->
       let%bind t' = Compiler_type.type_ t in
       return @@ i_nil t'
+  | E_make_empty_set t ->
+      let%bind t' = Compiler_type.type_ t in
+      return @@ i_empty_set t'
   | E_make_none o ->
       let%bind o' = Compiler_type.type_ o in
       return @@ i_none o'
diff --git a/src/compiler/compiler_type.ml b/src/compiler/compiler_type.ml
index 18ea463cf..2632f2bd8 100644
--- a/src/compiler/compiler_type.ml
+++ b/src/compiler/compiler_type.ml
@@ -35,6 +35,7 @@ module Ty = struct
     | T_pair _ -> fail (not_comparable "pair")
     | T_map _ -> fail (not_comparable "map")
     | T_list _ -> fail (not_comparable "list")
+    | T_set _ -> fail (not_comparable "set")
     | T_option _ -> fail (not_comparable "option")
     | T_contract _ -> fail (not_comparable "contract")
 
@@ -82,6 +83,10 @@ module Ty = struct
     | T_list t ->
         let%bind (Ex_ty t') = type_ t in
         ok @@ Ex_ty Contract_types.(list t')
+    | T_set t -> (
+        let%bind (Ex_comparable_ty t') = comparable_type t in
+        ok @@ Ex_ty Contract_types.(set t')
+      )
     | T_option t ->
         let%bind (Ex_ty t') = type_ t in
         ok @@ Ex_ty Contract_types.(option t')
@@ -142,6 +147,9 @@ let rec type_ : type_value -> O.michelson result =
   | T_list t ->
       let%bind t' = type_ t in
       ok @@ O.prim ~children:[t'] O.T_list
+  | T_set t ->
+      let%bind t' = type_ t in
+      ok @@ O.prim ~children:[t'] O.T_set
   | T_option o ->
       let%bind o' = type_ o in
       ok @@ O.prim ~children:[o'] O.T_option
diff --git a/src/compiler/uncompiler.ml b/src/compiler/uncompiler.ml
index ebf9f4028..81dc39967 100644
--- a/src/compiler/uncompiler.ml
+++ b/src/compiler/uncompiler.ml
@@ -29,6 +29,11 @@ let rec translate_value (Ex_typed_value (ty, value)) : value result =
         trace_option (simple_error "too big to fit an int") @@
         Alpha_context.Script_int.to_int n in
       ok @@ D_nat n
+  | (Timestamp_t _), n ->
+      let n =
+        Z.to_int @@
+        Alpha_context.Script_timestamp.to_zint n in
+      ok @@ D_timestamp n
   | (Mutez_t _), n ->
       let%bind n =
         generic_try (simple_error "too big to fit an int") @@
diff --git a/src/contracts/vote.mligo b/src/contracts/vote.mligo
new file mode 100644
index 000000000..3b4a4a857
--- /dev/null
+++ b/src/contracts/vote.mligo
@@ -0,0 +1,54 @@
+type storage = {
+  title : string ;
+  candidates : (string , int) map ;
+  voters : address set ;
+  beginning_time : timestamp ;
+  finish_time : timestamp ;
+}
+
+type init_action = (string * timestamp * timestamp)
+
+type action =
+  | Vote of string
+  | Init of (string * timestamp * timestamp)
+
+let init (init_params : init_action) (_ : storage) =
+  let (title , s , t) = init_params in
+  let candidates = Map [
+      ("Yes" , 0) ;
+      ("No" , 0)
+    ] in
+  (
+    ([] : operation list),
+    {
+      title = title ;
+      candidates = candidates ;
+      voters = (Set [] : address set) ;
+      beginning_time = s ;
+      finish_time = t ;
+    }
+  )
+
+let vote (parameter : string) (storage : storage) =
+  let now = Current.time () in
+  assert (now >= storage.beginning_time && storage.finish_time < now) ;
+
+  let addr = Current.source () in
+  assert (not Set.mem addr storage.voters) ;
+
+  let x = Map.find parameter storage.candidates in
+  (
+    ([] : operation list),
+    {
+      title = storage.title ;
+      candidates = Map.update parameter (Some (x + 1)) storage.candidates ;
+      voters = Set.add addr storage.voters ;
+      beginning_time = storage.beginning_time ;
+      finish_time = storage.finish_time ;
+    }
+  )
+						             )
+let main (action : action) (storage : storage) =
+  match action with
+  | Vote p -> vote p storage
+  | Init ps -> init ps storage
diff --git a/src/meta_michelson/contract.ml b/src/meta_michelson/contract.ml
index 7e38869c9..a9174a098 100644
--- a/src/meta_michelson/contract.ml
+++ b/src/meta_michelson/contract.ml
@@ -267,6 +267,7 @@ module Types = struct
   let key = Key_t None
 
   let list a = List_t (a, None)
+  let set a = Set_t (a, None)
   let assert_list = function
     | List_t (a, _) -> a
     | _ -> assert false
diff --git a/src/mini_c/PP.ml b/src/mini_c/PP.ml
index 51867e490..7840565e1 100644
--- a/src/mini_c/PP.ml
+++ b/src/mini_c/PP.ml
@@ -27,6 +27,7 @@ let rec type_ ppf : type_value -> _ = function
   | T_function(a, b) -> fprintf ppf "(%a) -> (%a)" type_ a type_ b
   | T_map(k, v) -> fprintf ppf "map(%a -> %a)" type_ k type_ v
   | T_list(t) -> fprintf ppf "list(%a)" type_ t
+  | T_set(t) -> fprintf ppf "set(%a)" type_ t
   | T_option(o) -> fprintf ppf "option(%a)" type_ o
   | T_contract(t) -> fprintf ppf "contract(%a)" type_ t
   | T_deep_closure(c, arg, ret) ->
@@ -45,6 +46,7 @@ let rec value ppf : value -> unit = function
   | D_operation _ -> fprintf ppf "operation[...bytes]"
   | D_int n -> fprintf ppf "%d" n
   | D_nat n -> fprintf ppf "+%d" n
+  | D_timestamp n -> fprintf ppf "+%d" n
   | D_tez n -> fprintf ppf "%dtz" n
   | D_unit -> fprintf ppf " "
   | D_string s -> fprintf ppf "\"%s\"" s
@@ -73,6 +75,7 @@ and expression' ppf (e:expression') = match e with
   | E_literal v -> fprintf ppf "%a" value v
   | E_make_empty_map _ -> fprintf ppf "map[]"
   | E_make_empty_list _ -> fprintf ppf "list[]"
+  | E_make_empty_set _ -> fprintf ppf "set[]"
   | E_make_none _ -> fprintf ppf "none"
   | E_if_bool (c, a, b) -> fprintf ppf "%a ? %a : %a" expression c expression a expression b
   | E_if_none (c, n, ((name, _) , s)) -> fprintf ppf "%a ?? %a : %s -> %a" expression c expression n name expression s
diff --git a/src/mini_c/combinators.ml b/src/mini_c/combinators.ml
index 670d63e5f..a5ed136b0 100644
--- a/src/mini_c/combinators.ml
+++ b/src/mini_c/combinators.ml
@@ -82,6 +82,10 @@ let get_t_list (t:type_value) = match t with
   | T_list t -> ok t
   | _ -> simple_fail "not a type list"
 
+let get_t_set (t:type_value) = match t with
+  | T_set t -> ok t
+  | _ -> simple_fail "not a type set"
+
 let get_left (v:value) = match v with
   | D_left b -> ok b
   | _ -> simple_fail "not a left"
diff --git a/src/mini_c/types.ml b/src/mini_c/types.ml
index 6e5bb4906..424763612 100644
--- a/src/mini_c/types.ml
+++ b/src/mini_c/types.ml
@@ -16,6 +16,7 @@ type type_value =
   | T_base of type_base
   | T_map of (type_value * type_value)
   | T_list of type_value
+  | T_set of type_value
   | T_contract of type_value
   | T_option of type_value
 
@@ -35,6 +36,7 @@ type value =
   | D_unit
   | D_bool of bool
   | D_nat of int
+  | D_timestamp of int
   | D_tez of int
   | D_int of int
   | D_string of string
@@ -64,6 +66,7 @@ and expression' =
   | E_variable of var_name
   | E_make_empty_map of (type_value * type_value)
   | E_make_empty_list of type_value
+  | E_make_empty_set of type_value
   | E_make_none of type_value
   | E_if_bool of expression * expression * expression
   | E_if_none of expression * expression * ((var_name * type_value) * expression)
diff --git a/src/operators/operators.ml b/src/operators/operators.ml
index c4ed39de0..1ccb179d2 100644
--- a/src/operators/operators.ml
+++ b/src/operators/operators.ml
@@ -118,6 +118,17 @@ module Simplify = struct
       ("Bytes.slice", "SLICE") ;
       ("Bytes.sub", "SLICE") ;
 
+      ("Set.mem" , "SET_MEM") ;
+      ("Set.empty" , "SET_EMPTY") ;
+      ("Set.add" , "SET_ADD") ;
+      ("Set.remove" , "SET_REMOVE") ;
+
+      ("Map.find_opt" , "MAP_FIND_OPT") ;
+      ("Map.find" , "MAP_FIND") ;
+      ("Map.update" , "MAP_UPDATE") ;
+      ("Map.add" , "MAP_ADD") ;
+      ("Map.remove" , "MAP_REMOVE") ;
+      
       ("String.length", "SIZE") ;
       ("String.size", "SIZE") ;
       ("String.slice", "SLICE") ;
diff --git a/src/parser/ligodity.ml b/src/parser/ligodity.ml
index fba239b59..b56d63ea2 100644
--- a/src/parser/ligodity.ml
+++ b/src/parser/ligodity.ml
@@ -34,6 +34,19 @@ let parse_file (source: string) : AST.t result =
           in
           simple_error str
         )
+      | Lexer.Error err -> (
+          let start = Lexing.lexeme_start_p lexbuf in
+          let end_ = Lexing.lexeme_end_p lexbuf in
+          let str = Format.sprintf
+              "Lexer error (%s) at \"%s\" from (%d, %d) to (%d, %d). In file \"%s|%s\"\n"
+              (err.value)
+              (Lexing.lexeme lexbuf)
+              start.pos_lnum (start.pos_cnum - start.pos_bol)
+              end_.pos_lnum (end_.pos_cnum - end_.pos_bol)
+              start.pos_fname source
+          in
+          simple_error str
+        )
       | exn ->
           let start = Lexing.lexeme_start_p lexbuf in
           let end_ = Lexing.lexeme_end_p lexbuf in
diff --git a/src/test/test.ml b/src/test/test.ml
index e07209be2..05db3980f 100644
--- a/src/test/test.ml
+++ b/src/test/test.ml
@@ -51,6 +51,7 @@ let () =
     Typer_tests.main ;
     Heap_tests.main ;
     Coase_tests.main ;
+    Vote_tests.main ;
     Bin_tests.main ;
   ] ;
   ()
diff --git a/src/test/vote_tests.ml b/src/test/vote_tests.ml
new file mode 100644
index 000000000..3fd337ab0
--- /dev/null
+++ b/src/test/vote_tests.ml
@@ -0,0 +1,31 @@
+open Trace
+open Ligo.Run
+open Test_helpers
+
+let get_program =
+  let s = ref None in
+  fun () -> match !s with
+    | Some s -> ok s
+    | None -> (
+        let%bind program = type_file "cameligo" "./contracts/vote.mligo" in
+        s := Some program ;
+        ok program
+      )
+
+open Ast_simplified
+
+let dummy_storage = ez_e_record [
+    ("title" , e_string "dummy") ;
+    ("candidates" , e_typed_map [] t_string t_int) ;
+    ("voters" , e_typed_set [] t_address) ;
+    ("beginning_time" , e_timestamp 0) ;
+    ("finish_time" , e_timestamp 0) ;
+  ]
+
+let init_vote () =
+  let%bind _program = get_program () in
+  ok ()
+
+let main = test_suite "Vote" [
+    (* test "type" init_vote ; *)
+  ]
diff --git a/src/transpiler/transpiler.ml b/src/transpiler/transpiler.ml
index 724a32b32..e61f98ec6 100644
--- a/src/transpiler/transpiler.ml
+++ b/src/transpiler/transpiler.ml
@@ -181,6 +181,7 @@ let rec translate_literal : AST.literal -> value = fun l -> match l with
   | Literal_bool b -> D_bool b
   | Literal_int n -> D_int n
   | Literal_nat n -> D_nat n
+  | Literal_timestamp n -> D_timestamp n
   | Literal_tez n -> D_tez n
   | Literal_bytes s -> D_bytes s
   | Literal_string s -> D_string s
@@ -362,6 +363,16 @@ and translate_annotated_expression (ae:AST.annotated_expression) : expression re
       let%bind (init : expression) = return @@ E_make_empty_list t in
       bind_fold_list aux init lst'
     )
+  | E_set lst -> (
+      let%bind t =
+        trace_strong (corner_case ~loc:__LOC__ "not a set") @@
+        Mini_c.Combinators.get_t_set tv in
+      let%bind lst' = bind_map_list (translate_annotated_expression) lst in
+      let aux : expression -> expression -> expression result = fun prev cur ->
+        return @@ E_constant ("CONS", [cur ; prev]) in
+      let%bind (init : expression) = return @@ E_make_empty_set t in
+      bind_fold_list aux init lst'
+    )
   | E_map m -> (
       let%bind (src, dst) =
         trace_strong (corner_case ~loc:__LOC__ "not a map") @@
diff --git a/src/typer/typer.ml b/src/typer/typer.ml
index a3f0f0140..fc0d9abef 100644
--- a/src/typer/typer.ml
+++ b/src/typer/typer.ml
@@ -416,6 +416,8 @@ and type_expression : environment -> ?tv_opt:O.type_value -> I.expression -> O.a
       return (E_literal (Literal_int n)) (t_int ())
   | E_literal (Literal_nat n) ->
       return (E_literal (Literal_nat n)) (t_nat ())
+  | E_literal (Literal_timestamp n) ->
+      return (E_literal (Literal_timestamp n)) (t_timestamp ())
   | E_literal (Literal_tez n) ->
       return (E_literal (Literal_tez n)) (t_tez ())
   | E_literal (Literal_address s) ->
@@ -501,6 +503,27 @@ and type_expression : environment -> ?tv_opt:O.type_value -> I.expression -> O.a
         ok (t_list ty ())
       in
       return (E_list lst') tv
+  | E_set lst ->
+      let%bind lst' = bind_map_list (type_expression e) lst in
+      let%bind tv =
+        let aux opt c =
+          match opt with
+          | None -> ok (Some c)
+          | Some c' ->
+              let%bind _eq = Ast_typed.assert_type_value_eq (c, c') in
+              ok (Some c') in
+        let%bind init = match tv_opt with
+          | None -> ok None
+          | Some ty ->
+              let%bind ty' = get_t_set ty in
+              ok (Some ty') in
+        let%bind ty =
+          let%bind opt = bind_fold_list aux init
+          @@ List.map get_type_annotation lst' in
+          trace_option (needs_annotation ae "empty set") opt in
+        ok (t_set ty ())
+      in
+      return (E_set lst') tv
   | E_map lst ->
       let%bind lst' = bind_map_list (bind_map_pair (type_expression e)) lst in
       let%bind tv =
@@ -752,6 +775,7 @@ let untype_literal (l:O.literal) : I.literal result =
   | Literal_unit -> ok Literal_unit
   | Literal_bool b -> ok (Literal_bool b)
   | Literal_nat n -> ok (Literal_nat n)
+  | Literal_timestamp n -> ok (Literal_timestamp n)
   | Literal_tez n -> ok (Literal_tez n)
   | Literal_int n -> ok (Literal_int n)
   | Literal_string s -> ok (Literal_string s)
@@ -803,6 +827,9 @@ let rec untype_expression (e:O.annotated_expression) : (I.expression) result =
   | E_list lst ->
       let%bind lst' = bind_map_list untype_expression lst in
       return (e_list lst')
+  | 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)
diff --git a/vendors/ligo-utils/tezos-utils/x_michelson.ml b/vendors/ligo-utils/tezos-utils/x_michelson.ml
index 5222abd63..462a40b63 100644
--- a/vendors/ligo-utils/tezos-utils/x_michelson.ml
+++ b/vendors/ligo-utils/tezos-utils/x_michelson.ml
@@ -47,6 +47,7 @@ let i_push_unit = i_push t_unit d_unit
 let i_push_string str = i_push t_string (string str)
 let i_none ty = prim ~children:[ty] I_NONE
 let i_nil ty = prim ~children:[ty] I_NIL
+let i_empty_set ty = prim ~children:[ty] I_EMPTY_SET
 let i_some = prim I_SOME
 let i_lambda arg ret body = prim ~children:[arg;ret;body] I_LAMBDA
 let i_empty_map src dst = prim ~children:[src;dst] I_EMPTY_MAP