diff --git a/compiler/driver.ml b/compiler/driver.ml
index 0f8cd771..26f266f7 100644
--- a/compiler/driver.ml
+++ b/compiler/driver.ml
@@ -243,7 +243,7 @@ let driver (source_file : Pos.input_file) (debug : bool) (unstyled : bool)
             0
         | Cli.OCaml | Cli.Python ->
             Cli.debug_print "Compiling program into lambda calculus...";
-            let prgm = Lcalc.Compile_with_exceptions.translate_program prgm in
+            let prgm = Lcalc.Compile_without_exceptions.translate_program prgm in
             let prgm =
               if optimize then begin
                 Cli.debug_print "Optimizing lambda calculus...";
diff --git a/compiler/lcalc/compile_without_exceptions.ml b/compiler/lcalc/compile_without_exceptions.ml
index 5703ae5c..a7388fe6 100644
--- a/compiler/lcalc/compile_without_exceptions.ml
+++ b/compiler/lcalc/compile_without_exceptions.ml
@@ -56,9 +56,9 @@ let rec translate_default (ctx : ctx) (exceptions : D.expr Pos.marked list)
   in
   exceptions
 
-(* non-existing for the moment. *)
 and translate_typ (t: D.typ Pos.marked) : D.typ Pos.marked =
-  let _ = t in assert false
+  (* Hack: If the type is D.TAny, it means for the compiler to not put any type annotation.*)
+  Pos.same_pos_as D.TAny t
 
 and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindlib.box =
 
@@ -74,7 +74,7 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
 
       let pos = Pos.get_position(Bindlib.unbox e1) in
       let x = A.Var.make ("e1", pos) in
-      let tau = failwith "todo" in
+      let tau = (D.TAny, pos) in
 
       let e2 = 
         let+ e1 = Bindlib.box (A.EVar (x, pos)) in
@@ -89,7 +89,7 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
       let pos = Pos.get_position(Bindlib.unbox e1) in
       let x = A.Var.make ("e1", pos) in
 
-      let tau = failwith "todo" in
+      let tau = (D.TAny, pos) in
 
       let e2 =
         let+ e1 = Bindlib.box (A.EVar (x, pos)) in
@@ -102,7 +102,7 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
     let pos = Pos.get_position(Bindlib.unbox e1) in
     let x = A.Var.make ("e1", pos) in
 
-    let tau = failwith "todo" in
+    let tau = (D.TAny, pos) in
 
     let e2 =
       let+ e1 = Bindlib.box (A.EVar (x, pos))
@@ -125,7 +125,7 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
       let x = A.Var.make ("e1", pos) in
 
       (* we can say staticly what is the type of tau here. *)
-      let tau = failwith "todo" in
+      let tau = (D.TAny, pos) in
 
       let e2 = 
         let+ e1 = Bindlib.box (A.EVar (x, pos))
@@ -136,11 +136,24 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
 
       A.make_letopt_in x tau e1 e2
 
-  | D.EAssert _e1 ->
+  | D.EAssert e1 ->
     (* don't know the semantic of EAssert. *)
     (* Bindlib.box_apply (fun e1 -> Pos.same_pos_as (A.EAssert e1) e) (translate_expr ctx e1) *)
 
-    failwith "todo"
+    
+
+    let e1 = translate_expr ctx e1 in
+    let pos = Pos.get_position (Bindlib.unbox e1) in
+    let x  = A.Var.make ("e1", pos) in
+    let tau = (D.TAny, pos) in
+
+    let e2 =
+      let+ e1 = Bindlib.box (A.EVar (x, pos)) in
+
+      same_pos @@ A.EAssert (e1, pos)
+    in
+
+    A.make_letopt_in x tau e1 e2
 
   | D.ErrorOnEmpty arg ->
 
@@ -148,7 +161,7 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
     let x = A.Var.make ("e1", pos) in
     let arg = translate_expr ctx arg in
 
-    let tau = failwith "todo" in
+    let tau = (D.TAny, pos) in
 
     let+ e2 = A.make_abs
     (Array.of_list [ x ])
@@ -165,7 +178,7 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
     let pos = Pos.get_position(Bindlib.unbox e1) in
     let x = A.Var.make ("e1", pos) in
 
-    let tau = failwith "todo" in
+    let tau = (D.TAny, pos) in
 
     let e2 =
       let+ e1 = Bindlib.box (A.EVar (x, pos))
@@ -193,8 +206,6 @@ and translate_expr (ctx : ctx) (e : D.expr Pos.marked) : A.expr Pos.marked Bindl
   | D.EDefault (exceptions, just, cons) ->
       translate_default ctx exceptions just cons (Pos.get_position e)
 
-
-(* no change here *)
 let translate_program (prgm : D.program) : A.program =
   {
     scopes =
diff --git a/compiler/lcalc/to_ocaml.ml b/compiler/lcalc/to_ocaml.ml
index 82c3ee3e..1696246b 100644
--- a/compiler/lcalc/to_ocaml.ml
+++ b/compiler/lcalc/to_ocaml.ml
@@ -327,7 +327,12 @@ let rec format_expr (ctx : Dcalc.Ast.decl_ctx) (fmt : Format.formatter) (e : exp
         format_exception
         (exc, Pos.get_position e)
         format_with_parens e2
-  | ESome _ | ENone | EMatchopt _ -> failwith "todo"
+  | ESome e1 ->
+    Format.fprintf fmt "@[<hov 2> Some@ %a@ @]" format_with_parens e1
+  | ENone -> Format.fprintf fmt "None@"
+  | EMatchopt (e1, e2, e3) ->
+    let x = assert false in
+    Format.fprintf fmt "@[<hov 2>match@ %a@]@ with@\n| None ->@[<hov 2>@ %a@]@\n| Some %a ->@[<hov 2>@ %a@ %a@]" format_expr e1 format_with_parens e2 format_var x format_with_parens e3 format_var x
 
 let format_struct_embedding (fmt : Format.formatter)
     ((struct_name, struct_fields) : D.StructName.t * (D.StructFieldName.t * D.typ Pos.marked) list)
diff --git a/default.nix b/default.nix
index 2531e987..93396368 100644
--- a/default.nix
+++ b/default.nix
@@ -34,7 +34,7 @@ buildDunePackage rec {
   ];
   doCheck = true;
 
-  patches = [ ./.nix/no-web.patch ];
+  # patches = [ ./.nix/no-web.patch ];
 
   meta = with lib; {
     homepage = "https://catala-lang.org";