diff --git a/src/proto_alpha/lib_protocol/ticket_accounting.ml b/src/proto_alpha/lib_protocol/ticket_accounting.ml
index 5eaf1ea7de319697dcda475442517cc29f2b344e..2dac9aaa1836a65e26301bab7d48e7682a659be1 100644
--- a/src/proto_alpha/lib_protocol/ticket_accounting.ml
+++ b/src/proto_alpha/lib_protocol/ticket_accounting.ml
@@ -51,11 +51,13 @@ module Ticket_token_map = struct
   include Ticket_token_map
 
   let balance_diff ctxt token map =
-    Ticket_token_map.find ctxt token map >|=? fun (amnt_opt, ctxt) ->
+    let open Lwt_tzresult_syntax in
+    let+ amnt_opt, ctxt = Ticket_token_map.find ctxt token map in
     (Option.value ~default:Z.zero amnt_opt, ctxt)
 
   let merge_overlap ctxt b1 b2 =
-    Gas.consume ctxt (Ticket_costs.add_z_cost b1 b2) >|? fun ctxt ->
+    let open Tzresult_syntax in
+    let+ ctxt = Gas.consume ctxt (Ticket_costs.add_z_cost b1 b2) in
     (Z.add b1 b2, ctxt)
 
   let of_list ctxt token_amounts =
@@ -64,41 +66,53 @@ module Ticket_token_map = struct
   let add ctxt = Ticket_token_map.merge ctxt ~merge_overlap
 
   let sub ctxt m1 m2 =
-    map_e
-      ctxt
-      (fun ctxt _ amount ->
-        Gas.consume ctxt (Ticket_costs.negate_cost amount) >|? fun ctxt ->
-        (Z.neg amount, ctxt))
-      m2
-    >>? fun (m2, ctxt) -> add ctxt m1 m2
+    let open Tzresult_syntax in
+    let* m2, ctxt =
+      map_e
+        ctxt
+        (fun ctxt _ex_token amount ->
+          let+ ctxt = Gas.consume ctxt (Ticket_costs.negate_cost amount) in
+          (Z.neg amount, ctxt))
+        m2
+    in
+    add ctxt m1 m2
 end
 
 let ticket_balances_of_value ctxt ~include_lazy ty value =
-  Ticket_scanner.tickets_of_value ~include_lazy ctxt ty value
-  >>=? fun (tickets, ctxt) ->
-  List.fold_left_e
-    (fun (acc, ctxt) ticket ->
-      let token, amount =
-        Ticket_scanner.ex_token_and_amount_of_ex_ticket ticket
-      in
+  let open Lwt_tzresult_syntax in
+  let* tickets, ctxt =
+    Ticket_scanner.tickets_of_value ~include_lazy ctxt ty value
+  in
+  let accum_ticket_balances (acc, ctxt) ticket =
+    let open Tzresult_syntax in
+    let token, amount =
+      Ticket_scanner.ex_token_and_amount_of_ex_ticket ticket
+    in
+    let+ ctxt =
       Gas.consume ctxt Ticket_costs.Constants.cost_collect_tickets_step
-      >|? fun ctxt ->
-      ( (token, Script_int.to_zint (amount :> Script_int.n Script_int.num))
-        :: acc,
-        ctxt ))
-    ([], ctxt)
-    tickets
-  >>?= fun (list, ctxt) -> Ticket_token_map.of_list ctxt list
+    in
+    ( (token, Script_int.to_zint (amount :> Script_int.n Script_int.num)) :: acc,
+      ctxt )
+  in
+  let*? token_amounts, ctxt =
+    List.fold_left_e accum_ticket_balances ([], ctxt) tickets
+  in
+  Ticket_token_map.of_list ctxt token_amounts
 
 let update_ticket_balances ctxt ~total_storage_diff token destinations =
+  let open Lwt_tzresult_syntax in
   List.fold_left_es
     (fun (tot_storage_diff, ctxt) (owner, delta) ->
-      Ticket_balance_key.of_ex_token ctxt ~owner token
-      >>=? fun (key_hash, ctxt) ->
-      Ticket_balance.adjust_balance ctxt key_hash ~delta
-      >>=? fun (storage_diff, ctxt) ->
-      Gas.consume ctxt (Ticket_costs.add_z_cost total_storage_diff storage_diff)
-      >>?= fun ctxt -> return (Z.add tot_storage_diff storage_diff, ctxt))
+      let* key_hash, ctxt = Ticket_balance_key.of_ex_token ctxt ~owner token in
+      let* storage_diff, ctxt =
+        Ticket_balance.adjust_balance ctxt key_hash ~delta
+      in
+      let*? ctxt =
+        Gas.consume
+          ctxt
+          (Ticket_costs.add_z_cost total_storage_diff storage_diff)
+      in
+      return (Z.add tot_storage_diff storage_diff, ctxt))
     (total_storage_diff, ctxt)
     destinations
 
@@ -109,6 +123,7 @@ let invalid_ticket_transfer_error
   Invalid_ticket_transfer {ticketer = Contract.to_b58check ticketer; amount}
 
 let update_ticket_balances_for_self_contract ctxt ~self_contract ticket_diffs =
+  let open Lwt_tzresult_syntax in
   List.fold_left_es
     (fun (total_storage_diff, ctxt) (ticket_token, amount) ->
       (* Diff is valid iff either:
@@ -118,10 +133,11 @@ let update_ticket_balances_for_self_contract ctxt ~self_contract ticket_diffs =
         let (Ticket_token.Ex_token {ticketer; _}) = ticket_token in
         Compare.Z.(amount <= Z.zero) || Contract.equal ticketer self_contract
       in
-      error_unless
-        is_valid_balance_update
-        (invalid_ticket_transfer_error ~ticket_token ~amount)
-      >>?= fun () ->
+      let*? () =
+        error_unless
+          is_valid_balance_update
+          (invalid_ticket_transfer_error ~ticket_token ~amount)
+      in
       update_ticket_balances
         ctxt
         ~total_storage_diff
@@ -132,12 +148,15 @@ let update_ticket_balances_for_self_contract ctxt ~self_contract ticket_diffs =
 
 let ticket_diffs_of_lazy_storage_diff ctxt ~storage_type_has_tickets
     lazy_storage_diff =
+  let open Lwt_tzresult_syntax in
   (* Only scan lazy-diffs for tickets in case the storage contains tickets. *)
   if Ticket_scanner.has_tickets storage_type_has_tickets then
-    Ticket_lazy_storage_diff.ticket_diffs_of_lazy_storage_diff
-      ctxt
-      lazy_storage_diff
-    >>=? fun (diffs, ctxt) -> Ticket_token_map.of_list ctxt diffs
+    let* diffs, ctxt =
+      Ticket_lazy_storage_diff.ticket_diffs_of_lazy_storage_diff
+        ctxt
+        lazy_storage_diff
+    in
+    Ticket_token_map.of_list ctxt diffs
   else return (Ticket_token_map.empty, ctxt)
 
 (* TODO #2465
@@ -171,39 +190,48 @@ let ticket_diffs_of_lazy_storage_diff ctxt ~storage_type_has_tickets
 let ticket_diffs ctxt ~self_contract ~arg_type_has_tickets
     ~storage_type_has_tickets ~arg ~old_storage ~new_storage ~lazy_storage_diff
     =
+  let open Lwt_tzresult_syntax in
   (* Collect ticket-token balances of the incoming parameters. *)
-  ticket_balances_of_value ctxt ~include_lazy:true arg_type_has_tickets arg
-  >>=? fun (arg_tickets, ctxt) ->
-  ticket_diffs_of_lazy_storage_diff
-    ctxt
-    ~storage_type_has_tickets
-    lazy_storage_diff
-  >>=? fun (lazy_storage_diff, ctxt) ->
-  ticket_balances_of_value
-    ctxt
-    ~include_lazy:false
-    storage_type_has_tickets
-    old_storage
-  >>=? fun (old_storage_strict, ctxt) ->
-  ticket_balances_of_value
-    ctxt
-    ~include_lazy:false
-    storage_type_has_tickets
-    new_storage
-  >>=? fun (new_storage_strict, ctxt) ->
-  Ticket_token_map.add ctxt new_storage_strict lazy_storage_diff
-  >>?= fun (additions, ctxt) ->
-  Ticket_token_map.sub ctxt additions old_storage_strict
-  >>?= fun (total_storage_diff, ctxt) ->
-  Ticket_token_map.sub ctxt total_storage_diff arg_tickets
-  >>?= fun (diff, ctxt) ->
-  Ticket_token_map.to_ticket_receipt
-    ctxt
-    ~owner:Destination.(Contract self_contract)
-    total_storage_diff
-  >>=? fun (ticket_receipt, ctxt) -> return (diff, ticket_receipt, ctxt)
+  let* arg_tickets, ctxt =
+    ticket_balances_of_value ctxt ~include_lazy:true arg_type_has_tickets arg
+  in
+  let* lazy_storage_diff, ctxt =
+    ticket_diffs_of_lazy_storage_diff
+      ctxt
+      ~storage_type_has_tickets
+      lazy_storage_diff
+  in
+  let* old_storage_strict, ctxt =
+    ticket_balances_of_value
+      ctxt
+      ~include_lazy:false
+      storage_type_has_tickets
+      old_storage
+  in
+  let* new_storage_strict, ctxt =
+    ticket_balances_of_value
+      ctxt
+      ~include_lazy:false
+      storage_type_has_tickets
+      new_storage
+  in
+  let*? additions, ctxt =
+    Ticket_token_map.add ctxt new_storage_strict lazy_storage_diff
+  in
+  let*? total_storage_diff, ctxt =
+    Ticket_token_map.sub ctxt additions old_storage_strict
+  in
+  let*? diff, ctxt = Ticket_token_map.sub ctxt total_storage_diff arg_tickets in
+  let* ticket_receipt, ctxt =
+    Ticket_token_map.to_ticket_receipt
+      ctxt
+      ~owner:Destination.(Contract self_contract)
+      total_storage_diff
+  in
+  return (diff, ticket_receipt, ctxt)
 
 let update_ticket_balances ctxt ~self_contract ~ticket_diffs operations =
+  let open Lwt_tzresult_syntax in
   let validate_spending_budget ctxt
       (Ticket_token.Ex_token {ticketer; _} as ticket_token) amount =
     if Contract.equal ticketer self_contract then
@@ -212,8 +240,9 @@ let update_ticket_balances ctxt ~self_contract ~ticket_diffs operations =
          stored in the ticket table and don't need to be updated here. *)
       return (true, ctxt)
     else
-      Ticket_token_map.balance_diff ctxt ticket_token ticket_diffs
-      >|=? fun (balance_diff, ctxt) ->
+      let+ balance_diff, ctxt =
+        Ticket_token_map.balance_diff ctxt ticket_token ticket_diffs
+      in
       (* The balance-diff represents the number of units of a ticket-token,
          that is changed for the [self] contract. A negative diff means that
          an amount of ticket-tokens were not saved in the storage and are
@@ -227,34 +256,41 @@ let update_ticket_balances ctxt ~self_contract ~ticket_diffs operations =
       (Compare.Z.(Script_int.to_zint amount <= Z.neg balance_diff), ctxt)
   in
   (* Collect diffs from operations *)
-  Ticket_operations_diff.ticket_diffs_of_operations ctxt operations
-  >>=? fun (ticket_op_diffs, ctxt) ->
+  let* ticket_op_diffs, ctxt =
+    Ticket_operations_diff.ticket_diffs_of_operations ctxt operations
+  in
   (* Update balances for self-contract. *)
-  Ticket_token_map.to_list ctxt ticket_diffs >>?= fun (ticket_diffs, ctxt) ->
-  update_ticket_balances_for_self_contract ctxt ~self_contract ticket_diffs
-  >>=? fun (total_storage_diff, ctxt) ->
+  let*? ticket_diffs, ctxt = Ticket_token_map.to_list ctxt ticket_diffs in
+  let* total_storage_diff, ctxt =
+    update_ticket_balances_for_self_contract ctxt ~self_contract ticket_diffs
+  in
   (* Update balances for operations. *)
   List.fold_left_es
     (fun (total_storage_diff, ctxt)
          {Ticket_operations_diff.ticket_token; total_amount; destinations} ->
       (* Verify that we are able to spend the given amount of ticket-tokens. *)
-      validate_spending_budget ctxt ticket_token total_amount
-      >>=? fun (is_valid_balance_update, ctxt) ->
-      error_unless
-        is_valid_balance_update
-        (invalid_ticket_transfer_error
-           ~ticket_token
-           ~amount:(Script_int.to_zint total_amount))
-      >>?= fun () ->
-      List.fold_left_e
-        (fun (acc, ctxt) (token, (amount : Script_typed_ir.ticket_amount)) ->
-          (* Consume some gas for for traversing the list. *)
-          Gas.consume ctxt Ticket_costs.Constants.cost_collect_tickets_step
-          >|? fun ctxt ->
-          ((token, Script_int.(to_zint (amount :> n num))) :: acc, ctxt))
-        ([], ctxt)
-        destinations
-      >>?= fun (destinations, ctxt) ->
+      let* is_valid_balance_update, ctxt =
+        validate_spending_budget ctxt ticket_token total_amount
+      in
+      let*? () =
+        error_unless
+          is_valid_balance_update
+          (invalid_ticket_transfer_error
+             ~ticket_token
+             ~amount:(Script_int.to_zint total_amount))
+      in
+      let*? destinations, ctxt =
+        List.fold_left_e
+          (fun (acc, ctxt) (token, (amount : Script_typed_ir.ticket_amount)) ->
+            (* Consume some gas for traversing the list. *)
+            let open Tzresult_syntax in
+            let+ ctxt =
+              Gas.consume ctxt Ticket_costs.Constants.cost_collect_tickets_step
+            in
+            ((token, Script_int.(to_zint (amount :> n num))) :: acc, ctxt))
+          ([], ctxt)
+          destinations
+      in
       update_ticket_balances ctxt ~total_storage_diff ticket_token destinations)
     (total_storage_diff, ctxt)
     ticket_op_diffs