diff --git a/src/bin/expect_tests/contract_tests.ml b/src/bin/expect_tests/contract_tests.ml
index 3bcb48aa0..3785881be 100644
--- a/src/bin/expect_tests/contract_tests.ml
+++ b/src/bin/expect_tests/contract_tests.ml
@@ -1174,7 +1174,7 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "create_contract_toplevel.mligo" ; "main" ] ;
   [%expect {|
-ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8, character 8. No free variable allowed in this lambda: variable 'store' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * string ))) : None return let rhs#812 = #P in let p = rhs#812.0 in let s = rhs#812.1 in ( list[] : (TO_list(operation)) , store ) , NONE() : (TO_option(key_hash)) , 300000000mutez , \"un\")","location":"in file \"create_contract_toplevel.mligo\", line 4, character 35 to line 8, character 8"}
+ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8, character 8. No free variable allowed in this lambda: variable 'store' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * string ))) : None return let rhs#654 = #P in let p = rhs#654.0 in let s = rhs#654.1 in ( list[] : (TO_list(operation)) , store ) , NONE() : (TO_option(key_hash)) , 300000000mutez , \"un\")","location":"in file \"create_contract_toplevel.mligo\", line 4, character 35 to line 8, character 8"}
 
 
  If you're not sure how to fix this error, you can
@@ -1187,7 +1187,7 @@ ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8,
 
   run_ligo_bad [ "compile-contract" ; bad_contract "create_contract_var.mligo" ; "main" ] ;
   [%expect {|
-ligo: in file "create_contract_var.mligo", line 6, character 35 to line 10, character 5. No free variable allowed in this lambda: variable 'a' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * int ))) : None return let rhs#815 = #P in let p = rhs#815.0 in let s = rhs#815.1 in ( list[] : (TO_list(operation)) , a ) , NONE() : (TO_option(key_hash)) , 300000000mutez , 1)","location":"in file \"create_contract_var.mligo\", line 6, character 35 to line 10, character 5"}
+ligo: in file "create_contract_var.mligo", line 6, character 35 to line 10, character 5. No free variable allowed in this lambda: variable 'a' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * int ))) : None return let rhs#657 = #P in let p = rhs#657.0 in let s = rhs#657.1 in ( list[] : (TO_list(operation)) , a ) , NONE() : (TO_option(key_hash)) , 300000000mutez , 1)","location":"in file \"create_contract_var.mligo\", line 6, character 35 to line 10, character 5"}
 
 
  If you're not sure how to fix this error, you can
diff --git a/src/main/compile/of_core.ml b/src/main/compile/of_core.ml
index c6c48c299..e6f0dfbba 100644
--- a/src/main/compile/of_core.ml
+++ b/src/main/compile/of_core.ml
@@ -26,7 +26,7 @@ let apply (entry_point : string) (param : Ast_core.expression) : Ast_core.expres
     { expression_content = Ast_core.E_variable name ;
       location = Virtual "generated entry-point variable" } in
   let applied : Ast_core.expression = 
-    { expression_content = Ast_core.E_application {expr1=entry_point_var; expr2=param} ;
+    { expression_content = Ast_core.E_application {lamb=entry_point_var; args=param} ;
       location = Virtual "generated application" } in
   ok applied
 
diff --git a/src/passes/10-interpreter/interpreter.ml b/src/passes/10-interpreter/interpreter.ml
index cdbee239c..1a04d35c4 100644
--- a/src/passes/10-interpreter/interpreter.ml
+++ b/src/passes/10-interpreter/interpreter.ml
@@ -270,7 +270,7 @@ and eval_literal : Ast_typed.literal -> value result = function
 and eval : Ast_typed.expression -> env -> value result
   = fun term env ->
     match term.expression_content with
-    | E_application ({expr1 = f; expr2 = args}) -> (
+    | E_application ({lamb = f; args}) -> (
       let%bind f' = eval f env in
       let%bind args' = eval args env in
       match f' with
diff --git a/src/passes/10-transpiler/transpiler.ml b/src/passes/10-transpiler/transpiler.ml
index 3cf73747e..2d726d2df 100644
--- a/src/passes/10-transpiler/transpiler.ml
+++ b/src/passes/10-transpiler/transpiler.ml
@@ -253,9 +253,9 @@ and transpile_annotated_expression (ae:AST.expression) : expression result =
       let%bind tv = transpile_environment_element_type ele in
       return ~tv @@ E_variable (name)
     )
-  | E_application {expr1;expr2} ->
-      let%bind a = transpile_annotated_expression expr1 in
-      let%bind b = transpile_annotated_expression expr2 in
+  | E_application {lamb; args} ->
+      let%bind a = transpile_annotated_expression lamb in
+      let%bind b = transpile_annotated_expression args in
       return @@ E_application (a, b)
   | E_constructor {constructor;element} -> (
       let%bind param' = transpile_annotated_expression element in
@@ -550,10 +550,10 @@ and transpile_recursive {fun_name; fun_type; lambda} =
       E_matching m -> 
         let%bind ty = transpile_type e.type_expression in
         matching fun_name loop_type shadowed m ty |
-      E_application {expr1;expr2} -> (
-        match expr1.expression_content,shadowed with
+      E_application {lamb;args} -> (
+        match lamb.expression_content,shadowed with
         E_variable name, false when Var.equal fun_name name -> 
-          let%bind expr = transpile_annotated_expression expr2 in
+          let%bind expr = transpile_annotated_expression args in
           ok @@ Expression.make (E_constant {cons_name=C_LOOP_CONTINUE;arguments=[expr]}) loop_type |
         _ -> 
           let%bind expr = transpile_annotated_expression e in
diff --git a/src/passes/3-self_ast_imperative/helpers.ml b/src/passes/3-self_ast_imperative/helpers.ml
index 22e426700..fc15f29e1 100644
--- a/src/passes/3-self_ast_imperative/helpers.ml
+++ b/src/passes/3-self_ast_imperative/helpers.ml
@@ -19,8 +19,8 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
   | E_look_up ab ->
       let%bind res = bind_fold_pair self init' ab in
       ok res
-  | E_application {expr1;expr2} -> (
-      let ab = (expr1,expr2) in
+  | E_application {lamb;args} -> (
+      let ab = (lamb,args) in
       let%bind res = bind_fold_pair self init' ab in
       ok res
     )
@@ -59,6 +59,11 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
   | E_recursive { lambda={result=e;_}; _} ->
       let%bind res = self init' e in
       ok res
+  | E_sequence {expr1;expr2} ->
+      let ab = (expr1,expr2) in
+      let%bind res = bind_fold_pair self init' ab in
+      ok res
+     
 
 and fold_cases : 'a folder -> 'a -> matching_expr -> 'a result = fun f init m ->
   match m with
@@ -145,10 +150,10 @@ let rec map_expression : exp_mapper -> expression -> expression result = fun f e
       let%bind e' = self c.element in
       return @@ E_constructor {c with element = e'}
   )
-  | E_application {expr1;expr2} -> (
-      let ab = (expr1,expr2) in
-      let%bind (a,b) = bind_map_pair self ab in
-      return @@ E_application {expr1=a;expr2=b}
+  | E_application {lamb;args} -> (
+      let ab = (lamb,args) in
+      let%bind (lamb,args) = bind_map_pair self ab in
+      return @@ E_application {lamb;args}
     )
   | E_let_in { let_binder ; mut; rhs ; let_result; inline } -> (
       let%bind rhs = self rhs in
@@ -167,6 +172,10 @@ let rec map_expression : exp_mapper -> expression -> expression result = fun f e
       let%bind args = bind_map_list self c.arguments in
       return @@ E_constant {c with arguments=args}
     )
+  | E_sequence {expr1;expr2} -> (
+      let%bind (expr1,expr2) = bind_map_pair self (expr1,expr2) in
+      return @@ E_sequence {expr1;expr2}
+    )
   | E_literal _ | E_variable _ | E_skip as e' -> return e'
 
 and map_type_expression : ty_exp_mapper -> type_expression -> type_expression result = fun f te ->
@@ -288,10 +297,10 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
       let%bind (res,e') = self init' c.element in
       ok (res, return @@ E_constructor {c with element = e'})
   )
-  | E_application {expr1;expr2} -> (
-      let ab = (expr1,expr2) in
+  | E_application {lamb;args} -> (
+      let ab = (lamb,args) in
       let%bind (res,(a,b)) = bind_fold_map_pair self init' ab in
-      ok (res, return @@ E_application {expr1=a;expr2=b})
+      ok (res, return @@ E_application {lamb=a;args=b})
     )
   | E_let_in { let_binder ; mut; rhs ; let_result; inline } -> (
       let%bind (res,rhs) = self init' rhs in
@@ -310,6 +319,10 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
       let%bind (res,args) = bind_fold_map_list self init' c.arguments in
       ok (res, return @@ E_constant {c with arguments=args})
     )
+  | E_sequence {expr1;expr2} -> (
+      let%bind (res,(expr1,expr2)) = bind_fold_map_pair self init' (expr1,expr2) in
+      ok (res, return @@ E_sequence {expr1;expr2})
+    )
   | E_literal _ | E_variable _ | E_skip as e' -> ok (init', return e')
 
 and fold_map_cases : 'a fold_mapper -> 'a -> matching_expr -> ('a * matching_expr) result = fun f init m ->
diff --git a/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml b/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml
index fc30c7e88..9cdfed78e 100644
--- a/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml
+++ b/src/passes/4-imperative_to_sugar/imperative_to_sugar.ml
@@ -68,10 +68,10 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind arguments = bind_map_list compile_expression arguments in
       return @@ O.E_constant {cons_name;arguments}
     | I.E_variable name     -> return @@ O.E_variable name
-    | I.E_application {expr1;expr2} -> 
-      let%bind expr1 = compile_expression expr1 in
-      let%bind expr2 = compile_expression expr2 in
-      return @@ O.E_application {expr1; expr2}
+    | I.E_application {lamb;args} -> 
+      let%bind lamb = compile_expression lamb in
+      let%bind args = compile_expression args in
+      return @@ O.E_application {lamb;args}
     | I.E_lambda lambda ->
       let%bind lambda = compile_lambda lambda in
       return @@ O.E_lambda lambda
@@ -85,7 +85,6 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind rhs = compile_expression rhs in
       let%bind let_result = compile_expression let_result in
       return @@ O.E_let_in {let_binder=(binder,ty_opt);inline;rhs;let_result}
-    | I.E_skip -> return @@ O.E_skip
     | I.E_constructor {constructor;element} ->
       let%bind element = compile_expression element in
       return @@ O.E_constructor {constructor;element}
@@ -134,6 +133,11 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind anno_expr = compile_expression anno_expr in
       let%bind type_annotation = compile_type_expression type_annotation in
       return @@ O.E_ascription {anno_expr; type_annotation}
+    | I.E_sequence {expr1; expr2} ->
+      let%bind expr1 = compile_expression expr1 in
+      let%bind expr2 = compile_expression expr2 in
+      return @@ O.E_sequence {expr1; expr2}
+    | I.E_skip -> return @@ O.E_skip
 and compile_lambda : I.lambda -> O.lambda result =
   fun {binder;input_type;output_type;result}->
     let%bind input_type = bind_map_option compile_type_expression input_type in
@@ -252,10 +256,10 @@ let rec uncompile_expression : O.expression -> I.expression result =
     let%bind arguments = bind_map_list uncompile_expression arguments in
     return @@ I.E_constant {cons_name;arguments}
   | O.E_variable name     -> return @@ I.E_variable name
-  | O.E_application {expr1;expr2} -> 
-    let%bind expr1 = uncompile_expression expr1 in
-    let%bind expr2 = uncompile_expression expr2 in
-    return @@ I.E_application {expr1; expr2}
+  | O.E_application {lamb; args} -> 
+    let%bind lamb = uncompile_expression lamb in
+    let%bind args = uncompile_expression args in
+    return @@ I.E_application {lamb; args}
   | O.E_lambda lambda ->
     let%bind lambda = uncompile_lambda lambda in
     return @@ I.E_lambda lambda
@@ -269,7 +273,6 @@ let rec uncompile_expression : O.expression -> I.expression result =
     let%bind rhs = uncompile_expression rhs in
     let%bind let_result = uncompile_expression let_result in
     return @@ I.E_let_in {let_binder=(binder,ty_opt);mut=false;inline;rhs;let_result}
-  | O.E_skip -> return @@ I.E_skip
   | O.E_constructor {constructor;element} ->
     let%bind element = uncompile_expression element in
     return @@ I.E_constructor {constructor;element}
@@ -318,6 +321,11 @@ let rec uncompile_expression : O.expression -> I.expression result =
     let%bind anno_expr = uncompile_expression anno_expr in
     let%bind type_annotation = uncompile_type_expression type_annotation in
     return @@ I.E_ascription {anno_expr; type_annotation}
+  | O.E_sequence {expr1; expr2} ->
+    let%bind expr1 = uncompile_expression expr1 in
+    let%bind expr2 = uncompile_expression expr2 in
+    return @@ I.E_sequence {expr1; expr2}
+  | O.E_skip -> return @@ I.E_skip
 
 and uncompile_lambda : O.lambda -> I.lambda result =
   fun {binder;input_type;output_type;result}->
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 c55c2561c..261bb1e81 100644
--- a/src/passes/6-sugar_to_core/sugar_to_core.ml
+++ b/src/passes/6-sugar_to_core/sugar_to_core.ml
@@ -68,10 +68,10 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind arguments = bind_map_list compile_expression arguments in
       return @@ O.E_constant {cons_name;arguments}
     | I.E_variable name     -> return @@ O.E_variable name
-    | I.E_application {expr1;expr2} -> 
-      let%bind expr1 = compile_expression expr1 in
-      let%bind expr2 = compile_expression expr2 in
-      return @@ O.E_application {expr1; expr2}
+    | I.E_application {lamb;args} -> 
+      let%bind lamb = compile_expression lamb in
+      let%bind args = compile_expression args in
+      return @@ O.E_application {lamb; args}
     | I.E_lambda lambda ->
       let%bind lambda = compile_lambda lambda in
       return @@ O.E_lambda lambda
@@ -85,7 +85,6 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind rhs = compile_expression rhs in
       let%bind let_result = compile_expression let_result in
       return @@ O.E_let_in {let_binder=(binder,ty_opt);inline;rhs;let_result}
-    | I.E_skip -> ok @@ O.e_unit ~loc:e.location ()
     | I.E_constructor {constructor;element} ->
       let%bind element = compile_expression element in
       return @@ O.E_constructor {constructor;element}
@@ -134,6 +133,11 @@ let rec compile_expression : I.expression -> O.expression result =
       let%bind anno_expr = compile_expression anno_expr in
       let%bind type_annotation = idle_type_expression type_annotation in
       return @@ O.E_ascription {anno_expr; type_annotation}
+    | I.E_sequence {expr1; expr2} ->
+      let%bind expr1 = compile_expression expr1 in
+      let%bind expr2 = compile_expression expr2 in
+      return @@ O.E_let_in {let_binder=(Var.of_name "_", Some O.t_unit); rhs=expr1;let_result=expr2; inline=false}
+    | I.E_skip -> ok @@ O.e_unit ~loc:e.location ()
 
 and compile_lambda : I.lambda -> O.lambda result =
   fun {binder;input_type;output_type;result}->
@@ -253,10 +257,10 @@ let rec uncompile_expression : O.expression -> I.expression result =
     let%bind arguments = bind_map_list uncompile_expression arguments in
     return @@ I.E_constant {cons_name;arguments}
   | O.E_variable name     -> return @@ I.E_variable name
-  | O.E_application {expr1;expr2} -> 
-    let%bind expr1 = uncompile_expression expr1 in
-    let%bind expr2 = uncompile_expression expr2 in
-    return @@ I.E_application {expr1; expr2}
+  | O.E_application {lamb; args} -> 
+    let%bind lamb = uncompile_expression lamb in
+    let%bind args = uncompile_expression args in
+    return @@ I.E_application {lamb; args}
   | O.E_lambda lambda ->
     let%bind lambda = uncompile_lambda lambda in
     return @@ I.E_lambda lambda
@@ -264,6 +268,10 @@ let rec uncompile_expression : O.expression -> I.expression result =
     let%bind fun_type = uncompile_type_expression fun_type in
     let%bind lambda = uncompile_lambda lambda in
     return @@ I.E_recursive {fun_name;fun_type;lambda}
+  | O.E_let_in {let_binder;inline=false;rhs=expr1;let_result=expr2} when let_binder = (Var.of_name "_", Some O.t_unit) ->
+    let%bind expr1 = uncompile_expression expr1 in
+    let%bind expr2 = uncompile_expression expr2 in
+    return @@ I.E_sequence {expr1;expr2}
   | O.E_let_in {let_binder;inline;rhs;let_result} ->
     let (binder,ty_opt) = let_binder in
     let%bind ty_opt = bind_map_option uncompile_type_expression ty_opt in
diff --git a/src/passes/8-typer-new/typer.ml b/src/passes/8-typer-new/typer.ml
index 215df7ebd..0dcae68d0 100644
--- a/src/passes/8-typer-new/typer.ml
+++ b/src/passes/8-typer-new/typer.ml
@@ -679,11 +679,11 @@ and type_expression : environment -> Solver.state -> ?tv_opt:O.type_expression -
    *   let%bind (name', tv) =
    *     type_constant name tv_lst tv_opt ae.location in
    *   return (E_constant (name' , lst')) tv *)
-  | E_application {expr1;expr2} ->
-    let%bind (f' , state') = type_expression e state expr1 in
-    let%bind (arg , state'') = type_expression e state' expr2 in
-    let wrapped = Wrap.application f'.type_expression arg.type_expression in
-    return_wrapped (E_application {expr1=f';expr2=arg}) state'' wrapped
+  | E_application {lamb;args} ->
+    let%bind (f' , state') = type_expression e state lamb in
+    let%bind (args , state'') = type_expression e state' args in
+    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
@@ -1037,9 +1037,9 @@ let rec untype_expression (e:O.expression) : (I.expression) result =
       return (e_constant cons_name lst')
   | E_variable (n) ->
     return (e_variable (n))
-  | E_application {expr1;expr2} ->
-      let%bind f' = untype_expression expr1 in
-      let%bind arg' = untype_expression expr2 in
+  | E_application {lamb;args} ->
+      let%bind f' = untype_expression lamb in
+      let%bind arg' = untype_expression args in
       return (e_application f' arg')
   | E_lambda lambda ->
       let%bind lambda = untype_lambda e.type_expression lambda in
diff --git a/src/passes/8-typer-old/typer.ml b/src/passes/8-typer-old/typer.ml
index bc6924df0..5a11d6184 100644
--- a/src/passes/8-typer-old/typer.ml
+++ b/src/passes/8-typer-old/typer.ml
@@ -688,21 +688,21 @@ and type_expression' : environment -> ?tv_opt:O.type_expression -> I.expression
       let%bind (name', tv) =
         type_constant cons_name tv_lst tv_opt in
       return (E_constant {cons_name=name';arguments=lst'}) tv
-  | E_application {expr1;expr2} ->
-      let%bind expr1' = type_expression' e expr1 in
-      let%bind expr2 = type_expression' e expr2 in
-      let%bind tv = match expr1'.type_expression.type_content with
+  | E_application {lamb; args} ->
+      let%bind lamb' = type_expression' e lamb in
+      let%bind args' = type_expression' e args in
+      let%bind tv = match lamb'.type_expression.type_content with
         | T_arrow {type1;type2} ->
-            let%bind _ = O.assert_type_expression_eq (type1, expr2.type_expression) in
+            let%bind _ = O.assert_type_expression_eq (type1, args'.type_expression) in
             ok type2
         | _ ->
           fail @@ type_error_approximate
             ~expected:"should be a function type"
-            ~expression:expr1
-            ~actual:expr1'.type_expression
-            expr1'.location
+            ~expression:lamb
+            ~actual:lamb'.type_expression
+            lamb'.location
       in
-      return (E_application {expr1=expr1';expr2}) tv
+      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
@@ -841,9 +841,9 @@ let rec untype_expression (e:O.expression) : (I.expression) result =
       return (e_constant cons_name lst')
   | E_variable n ->
       return (e_variable (n))
-  | E_application {expr1;expr2} ->
-      let%bind f' = untype_expression expr1 in
-      let%bind arg' = untype_expression expr2 in
+  | E_application {lamb;args} ->
+      let%bind f' = untype_expression lamb in
+      let%bind arg' = untype_expression args in
       return (e_application f' arg')
   | E_lambda {binder ; result} -> (
       let%bind io = get_t_function ty in
diff --git a/src/passes/9-self_ast_typed/helpers.ml b/src/passes/9-self_ast_typed/helpers.ml
index 818cdccf5..2da8a766e 100644
--- a/src/passes/9-self_ast_typed/helpers.ml
+++ b/src/passes/9-self_ast_typed/helpers.ml
@@ -19,8 +19,8 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
   | E_look_up ab ->
       let%bind res = bind_fold_pair self init' ab in
       ok res
-  | E_application {expr1;expr2} -> (
-      let ab = (expr1,expr2) in
+  | E_application {lamb; args} -> (
+      let ab = (lamb, args) in
       let%bind res = bind_fold_pair self init' ab in
       ok res
     )
@@ -135,10 +135,10 @@ let rec map_expression : mapper -> expression -> expression result = fun f e ->
       let%bind e' = self c.element in
       return @@ E_constructor {c with element = e'}
   )
-  | E_application {expr1;expr2} -> (
-      let ab = (expr1,expr2) in
+  | E_application {lamb; args} -> (
+      let ab = (lamb, args) in
       let%bind (a,b) = bind_map_pair self ab in
-      return @@ E_application {expr1=a;expr2=b}
+      return @@ E_application {lamb=a;args=b}
     )
   | E_let_in { let_binder ; rhs ; let_result; inline } -> (
       let%bind rhs = self rhs in
@@ -251,10 +251,10 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
       let%bind (res,e') = self init' c.element in
       ok (res, return @@ E_constructor {c with element = e'})
   )
-  | E_application {expr1;expr2} -> (
-      let ab = (expr1,expr2) in
+  | E_application {lamb;args} -> (
+      let ab = (lamb, args) in
       let%bind (res,(a,b)) = bind_fold_map_pair self init' ab in
-      ok (res, return @@ E_application {expr1=a;expr2=b})
+      ok (res, return @@ E_application {lamb=a;args=b})
     )
   | E_let_in { let_binder ; rhs ; let_result; inline } -> (
       let%bind (res,rhs) = self init' rhs in
diff --git a/src/passes/9-self_ast_typed/tail_recursion.ml b/src/passes/9-self_ast_typed/tail_recursion.ml
index 3e971c79e..610484a38 100644
--- a/src/passes/9-self_ast_typed/tail_recursion.ml
+++ b/src/passes/9-self_ast_typed/tail_recursion.ml
@@ -24,9 +24,9 @@ let rec check_recursive_call : expression_variable -> bool -> expression -> unit
     Assert.assert_true (final_path || n <> v) in
     ok ()
     )
-  | E_application {expr1;expr2} ->
-    let%bind _ = check_recursive_call n final_path expr1 in
-    let%bind _ = check_recursive_call n false expr2 in
+  | E_application {lamb;args} ->
+    let%bind _ = check_recursive_call n final_path lamb in
+    let%bind _ = check_recursive_call n false args in
     ok ()
   | E_lambda {result;_} ->
     let%bind _ = check_recursive_call n final_path result in
diff --git a/src/stages/1-ast_imperative/PP.ml b/src/stages/1-ast_imperative/PP.ml
index 576575d69..ebb4bd83e 100644
--- a/src/stages/1-ast_imperative/PP.ml
+++ b/src/stages/1-ast_imperative/PP.ml
@@ -18,8 +18,8 @@ and expression_content ppf (ec : expression_content) =
       literal ppf l
   | E_variable n ->
       fprintf ppf "%a" expression_variable n
-  | E_application app ->
-      fprintf ppf "(%a)@(%a)" expression app.expr1 expression app.expr2
+  | E_application {lamb;args} ->
+      fprintf ppf "(%a)@(%a)" expression lamb expression args
   | E_constructor c ->
       fprintf ppf "%a(%a)" constructor c.constructor expression c.element
   | E_constant c ->
@@ -59,11 +59,13 @@ and expression_content ppf (ec : expression_content) =
         expression_content (E_lambda lambda)
   | E_let_in { let_binder ; mut; rhs ; let_result; inline } ->    
       fprintf ppf "let %a%a = %a%a in %a" option_mut mut option_type_name let_binder expression rhs option_inline inline expression let_result
-  | E_skip ->
-      fprintf ppf "skip"
   | E_ascription {anno_expr; type_annotation} ->
       fprintf ppf "%a : %a" expression anno_expr type_expression
         type_annotation
+  | E_sequence {expr1;expr2} ->
+      fprintf ppf "%a;\n%a" expression expr1 expression expr2
+  | E_skip ->
+      fprintf ppf "skip"
 
 and option_type_name ppf
     ((n, ty_opt) : expression_variable * type_expression option) =
diff --git a/src/stages/1-ast_imperative/combinators.ml b/src/stages/1-ast_imperative/combinators.ml
index ceacdcc4e..92a1dbe73 100644
--- a/src/stages/1-ast_imperative/combinators.ml
+++ b/src/stages/1-ast_imperative/combinators.ml
@@ -125,11 +125,11 @@ let e_skip ?loc () = make_expr ?loc @@ E_skip
 let e_let_in ?loc (binder, ascr) mut inline rhs let_result = 
   make_expr ?loc @@ E_let_in { let_binder = (binder, ascr) ; mut; rhs ; let_result; inline }
 let e_annotation ?loc anno_expr ty = make_expr ?loc @@ E_ascription {anno_expr; type_annotation = ty}
-let e_application ?loc a b = make_expr ?loc @@ E_application {expr1=a ; expr2=b}
+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_sequence ?loc expr1 expr2 = e_let_in ?loc (Var.fresh (), Some t_unit) false false expr1 expr2
+let e_sequence ?loc expr1 expr2 = make_expr ?loc @@ E_sequence {expr1; expr2}
 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/1-ast_imperative/misc.ml b/src/stages/1-ast_imperative/misc.ml
index f2094d3ca..324529525 100644
--- a/src/stages/1-ast_imperative/misc.ml
+++ b/src/stages/1-ast_imperative/misc.ml
@@ -184,7 +184,7 @@ let rec assert_value_eq (a, b: (expression * expression )) : unit result =
   | (E_application _, _) | (E_let_in _, _)
   | (E_recursive _,_) | (E_record_accessor _, _)
   | (E_look_up _, _) | (E_matching _, _)
-  | (E_skip, _) -> simple_fail "comparing not a value"
+  | (E_sequence _, _) | (E_skip, _) -> simple_fail "comparing not a value"
 
 let is_value_eq (a , b) = to_bool @@ assert_value_eq (a , b)
 
diff --git a/src/stages/1-ast_imperative/types.ml b/src/stages/1-ast_imperative/types.ml
index 6d64cafd1..4d0d0bd68 100644
--- a/src/stages/1-ast_imperative/types.ml
+++ b/src/stages/1-ast_imperative/types.ml
@@ -36,7 +36,6 @@ and expression_content =
   | E_lambda of lambda
   | E_recursive of recursive
   | E_let_in of let_in
-  | E_skip
   (* Variant *)
   | E_constructor of constructor (* For user defined constructors *)
   | E_matching of matching
@@ -44,21 +43,26 @@ and expression_content =
   | E_record of expression label_map
   | E_record_accessor of accessor
   | E_record_update of update
+  (* Advanced *)
+  | E_ascription of ascription
+  (* Sugar *)
+  | E_sequence of sequence
+  | E_skip
   (* Data Structures *)
-  (* TODO : move to constant*)
-  | E_map of (expression * expression) list (*move to operator *)
-  | E_big_map of (expression * expression) list (*move to operator *)
+  | E_map of (expression * expression) list 
+  | E_big_map of (expression * expression) list
   | E_list of expression list
   | E_set of expression list
   | E_look_up of (expression * expression)
-  (* Advanced *)
-  | E_ascription of ascription
 
 and constant =
   { cons_name: constant' (* this is at the end because it is huge *)
   ; arguments: expression list }
 
-and application = {expr1: expression; expr2: expression}
+and application = {
+  lamb: expression ; 
+  args: expression ;
+  }
 
 and lambda =
   { binder: expression_variable
@@ -92,6 +96,10 @@ and matching =
   }
 
 and ascription = {anno_expr: expression; type_annotation: type_expression}
+and sequence = {
+  expr1: expression ;
+  expr2: expression ;
+  }
 
 and environment_element_definition =
   | ED_binder
diff --git a/src/stages/2-ast_sugar/PP.ml b/src/stages/2-ast_sugar/PP.ml
index c1288c6f3..d4a4ead08 100644
--- a/src/stages/2-ast_sugar/PP.ml
+++ b/src/stages/2-ast_sugar/PP.ml
@@ -18,8 +18,8 @@ and expression_content ppf (ec : expression_content) =
       literal ppf l
   | E_variable n ->
       fprintf ppf "%a" expression_variable n
-  | E_application app ->
-      fprintf ppf "(%a)@(%a)" expression app.expr1 expression app.expr2
+  | E_application {lamb;args} ->
+      fprintf ppf "(%a)@(%a)" expression lamb expression args
   | E_constructor c ->
       fprintf ppf "%a(%a)" constructor c.constructor expression c.element
   | E_constant c ->
@@ -58,11 +58,12 @@ and expression_content ppf (ec : expression_content) =
         cases
   | E_let_in { let_binder ; rhs ; let_result; inline } ->    
     fprintf ppf "let %a = %a%a in %a" option_type_name let_binder expression rhs option_inline inline expression let_result
+  | E_sequence {expr1;expr2} ->
+      fprintf ppf "%a;\n%a" expression expr1 expression expr2
+  | E_ascription {anno_expr; type_annotation} ->
+      fprintf ppf "%a : %a" expression anno_expr type_expression type_annotation
   | E_skip ->
       fprintf ppf "skip"
-  | E_ascription {anno_expr; type_annotation} ->
-      fprintf ppf "%a : %a" expression anno_expr type_expression
-        type_annotation
 
 and option_type_name ppf
     ((n, ty_opt) : expression_variable * type_expression option) =
diff --git a/src/stages/2-ast_sugar/combinators.ml b/src/stages/2-ast_sugar/combinators.ml
index 04a336e93..759d6fc55 100644
--- a/src/stages/2-ast_sugar/combinators.ml
+++ b/src/stages/2-ast_sugar/combinators.ml
@@ -125,11 +125,11 @@ let e_skip ?loc () = make_expr ?loc @@ E_skip
 let e_let_in ?loc (binder, ascr) inline rhs let_result = 
   make_expr ?loc @@ E_let_in { let_binder = (binder, ascr) ; rhs ; let_result; inline }
 let e_annotation ?loc anno_expr ty = make_expr ?loc @@ E_ascription {anno_expr; type_annotation = ty}
-let e_application ?loc a b = make_expr ?loc @@ E_application {expr1=a ; expr2=b}
+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_sequence ?loc expr1 expr2 = e_let_in ?loc (Var.fresh (), Some t_unit) false expr1 expr2
+let e_sequence ?loc expr1 expr2 = make_expr ?loc @@ E_sequence {expr1; expr2}
 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/2-ast_sugar/misc.ml b/src/stages/2-ast_sugar/misc.ml
index f2094d3ca..324529525 100644
--- a/src/stages/2-ast_sugar/misc.ml
+++ b/src/stages/2-ast_sugar/misc.ml
@@ -184,7 +184,7 @@ let rec assert_value_eq (a, b: (expression * expression )) : unit result =
   | (E_application _, _) | (E_let_in _, _)
   | (E_recursive _,_) | (E_record_accessor _, _)
   | (E_look_up _, _) | (E_matching _, _)
-  | (E_skip, _) -> simple_fail "comparing not a value"
+  | (E_sequence _, _) | (E_skip, _) -> simple_fail "comparing not a value"
 
 let is_value_eq (a , b) = to_bool @@ assert_value_eq (a , b)
 
diff --git a/src/stages/2-ast_sugar/types.ml b/src/stages/2-ast_sugar/types.ml
index dffb887bb..81091dea7 100644
--- a/src/stages/2-ast_sugar/types.ml
+++ b/src/stages/2-ast_sugar/types.ml
@@ -36,7 +36,6 @@ and expression_content =
   | E_lambda of lambda
   | E_recursive of recursive
   | E_let_in of let_in
-  | E_skip
   (* Variant *)
   | E_constructor of constructor (* For user defined constructors *)
   | E_matching of matching
@@ -44,21 +43,26 @@ and expression_content =
   | E_record of expression label_map
   | E_record_accessor of accessor
   | E_record_update of update
+  (* Advanced *)
+  | E_ascription of ascription
+  (* Sugar *)
+  | E_sequence of sequence
+  | E_skip
   (* Data Structures *)
-  (* TODO : move to constant*)
-  | E_map of (expression * expression) list (*move to operator *)
-  | E_big_map of (expression * expression) list (*move to operator *)
+  | E_map of (expression * expression) list 
+  | E_big_map of (expression * expression) list
   | E_list of expression list
   | E_set of expression list
   | E_look_up of (expression * expression)
-  (* Advanced *)
-  | E_ascription of ascription
 
 and constant =
   { cons_name: constant' (* this is at the end because it is huge *)
   ; arguments: expression list }
 
-and application = {expr1: expression; expr2: expression}
+and application = {
+  lamb: expression ; 
+  args: expression ;
+  }
 
 and lambda =
   { binder: expression_variable
@@ -91,6 +95,10 @@ and matching =
   }
 
 and ascription = {anno_expr: expression; type_annotation: type_expression}
+and sequence = {
+  expr1: expression ;
+  expr2: expression ;
+  }
 
 and environment_element_definition =
   | ED_binder
diff --git a/src/stages/3-ast_core/PP.ml b/src/stages/3-ast_core/PP.ml
index 88d4875c5..3410a96fb 100644
--- a/src/stages/3-ast_core/PP.ml
+++ b/src/stages/3-ast_core/PP.ml
@@ -18,8 +18,8 @@ and expression_content ppf (ec : expression_content) =
       literal ppf l
   | E_variable n ->
       fprintf ppf "%a" expression_variable n
-  | E_application app ->
-      fprintf ppf "(%a)@(%a)" expression app.expr1 expression app.expr2
+  | E_application {lamb;args} ->
+      fprintf ppf "(%a)@(%a)" expression lamb expression args
   | E_constructor c ->
       fprintf ppf "%a(%a)" constructor c.constructor expression c.element
   | E_constant c ->
diff --git a/src/stages/3-ast_core/combinators.ml b/src/stages/3-ast_core/combinators.ml
index ac1ee3798..db2417902 100644
--- a/src/stages/3-ast_core/combinators.ml
+++ b/src/stages/3-ast_core/combinators.ml
@@ -124,11 +124,10 @@ let e_variable ?loc v = make_expr ?loc @@ E_variable v
 let e_let_in ?loc (binder, ascr) inline rhs let_result = 
   make_expr ?loc @@ E_let_in { let_binder = (binder,ascr) ; rhs ; let_result; inline }
 let e_annotation ?loc anno_expr ty = make_expr ?loc @@ E_ascription {anno_expr; type_annotation = ty}
-let e_application ?loc a b = make_expr ?loc @@ E_application {expr1=a ; expr2=b}
+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_sequence ?loc expr1 expr2 = e_let_in ?loc (Var.fresh (), Some t_unit) false expr1 expr2
 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 b962ce3c6..ae0aab1bd 100644
--- a/src/stages/3-ast_core/combinators.mli
+++ b/src/stages/3-ast_core/combinators.mli
@@ -83,7 +83,6 @@ val e_matching_bool : ?loc:Location.t -> expression -> expression -> expression
 val e_accessor : ?loc:Location.t -> expression -> string -> expression
 val e_accessor_list : ?loc:Location.t -> expression -> string list -> expression
 val e_variable : ?loc:Location.t -> expression_variable -> expression
-val e_sequence : ?loc:Location.t -> expression -> expression -> expression
 val e_cond: ?loc:Location.t -> expression -> expression -> expression -> expression
 val e_let_in : ?loc:Location.t -> ( expression_variable * type_expression option ) -> bool -> expression -> expression -> expression
 val e_annotation : ?loc:Location.t -> expression -> type_expression -> expression
diff --git a/src/stages/3-ast_core/types.ml b/src/stages/3-ast_core/types.ml
index 781214f51..2b8f0dbc2 100644
--- a/src/stages/3-ast_core/types.ml
+++ b/src/stages/3-ast_core/types.ml
@@ -57,7 +57,10 @@ and constant =
   { cons_name: constant' (* this is at the end because it is huge *)
   ; arguments: expression list }
 
-and application = {expr1: expression; expr2: expression}
+and application = {
+  lamb: expression ; 
+  args: expression ;
+  }
 
 and lambda =
   { binder: expression_variable
diff --git a/src/stages/4-ast_typed/PP.ml b/src/stages/4-ast_typed/PP.ml
index aed4648c5..1325d0476 100644
--- a/src/stages/4-ast_typed/PP.ml
+++ b/src/stages/4-ast_typed/PP.ml
@@ -19,8 +19,8 @@ and expression_content ppf (ec: expression_content) =
       literal ppf l
   | E_variable n ->
       fprintf ppf "%a" expression_variable n
-  | E_application app ->
-      fprintf ppf "(%a)@(%a)" expression app.expr1 expression app.expr2
+  | E_application {lamb;args} ->
+      fprintf ppf "(%a)@(%a)" expression lamb expression args
   | E_constructor c ->
       fprintf ppf "%a(%a)" constructor c.constructor expression c.element
   | E_constant c ->
diff --git a/src/stages/4-ast_typed/combinators.ml b/src/stages/4-ast_typed/combinators.ml
index e9071df97..014ab8f2f 100644
--- a/src/stages/4-ast_typed/combinators.ml
+++ b/src/stages/4-ast_typed/combinators.ml
@@ -294,7 +294,7 @@ let e_chain_id s : expression_content = E_literal (Literal_chain_id s)
 let e_operation s : expression_content = E_literal (Literal_operation s)
 let e_lambda l : expression_content = E_lambda l
 let e_pair a b : expression_content = ez_e_record [(Label "0",a);(Label "1", b)]
-let e_application expr1 expr2 : expression_content = E_application {expr1;expr2}
+let e_application lamb args : expression_content = E_application {lamb;args}
 let e_variable v : expression_content = E_variable v
 let e_list lst : expression_content = E_list lst
 let e_let_in let_binder inline rhs let_result = E_let_in { let_binder ; rhs ; let_result; inline }
diff --git a/src/stages/4-ast_typed/misc.ml b/src/stages/4-ast_typed/misc.ml
index 20a778f9c..04efcca5f 100644
--- a/src/stages/4-ast_typed/misc.ml
+++ b/src/stages/4-ast_typed/misc.ml
@@ -206,7 +206,7 @@ module Free_variables = struct
         | true -> empty
         | false -> singleton name
       )
-    | E_application {expr1;expr2} -> unions @@ List.map self [ expr1 ; expr2 ]
+    | E_application {lamb;args} -> unions @@ List.map self [ lamb ; args ]
     | E_constructor {element;_} -> self element
     | E_record m -> unions @@ List.map self @@ LMap.to_list m
     | E_record_accessor {expr;_} -> self expr
diff --git a/src/stages/4-ast_typed/misc_smart.ml b/src/stages/4-ast_typed/misc_smart.ml
index 414f01670..0040f7d90 100644
--- a/src/stages/4-ast_typed/misc_smart.ml
+++ b/src/stages/4-ast_typed/misc_smart.ml
@@ -63,8 +63,8 @@ module Captured_variables = struct
         | ED_binder -> ok empty
         | ED_declaration {expr=_ ; free_variables=_} -> simple_fail "todo"
       )
-    | E_application {expr1;expr2} ->
-      let%bind lst' = bind_map_list self [ expr1 ; expr2 ] in
+    | E_application {lamb;args} ->
+      let%bind lst' = bind_map_list self [ lamb ; args ] in
       ok @@ unions lst'
     | E_constructor {element;_} -> self element
     | E_record m ->
diff --git a/src/stages/4-ast_typed/types.ml b/src/stages/4-ast_typed/types.ml
index a0d7c067a..fdb24969b 100644
--- a/src/stages/4-ast_typed/types.ml
+++ b/src/stages/4-ast_typed/types.ml
@@ -61,7 +61,10 @@ and constant =
   { cons_name: constant'
   ; arguments: expression list }
 
-and application = {expr1: expression; expr2: expression}
+and application = {
+  lamb: expression ; 
+  args: expression ;
+  }
 
 and lambda =  {
     binder: expression_variable ;
diff --git a/src/stages/typesystem/misc.ml b/src/stages/typesystem/misc.ml
index dcb46929b..4b60cf454 100644
--- a/src/stages/typesystem/misc.ml
+++ b/src/stages/typesystem/misc.ml
@@ -151,10 +151,10 @@ module Substitution = struct
       | T.E_variable        tv ->
         let%bind tv = s_variable ~substs tv in
         ok @@ T.E_variable tv
-      | T.E_application {expr1;expr2} ->
-        let%bind expr1 = s_expression ~substs expr1 in
-        let%bind expr2 = s_expression ~substs expr2 in
-        ok @@ T.E_application {expr1;expr2}
+      | T.E_application {lamb;args} ->
+        let%bind lamb = s_expression ~substs lamb in
+        let%bind args = s_expression ~substs args in
+        ok @@ T.E_application {lamb;args}
       | T.E_lambda          { binder; result } ->
         let%bind binder = s_variable ~substs binder in
         let%bind result = s_expression ~substs result in