diff --git a/src/main.ml b/src/main.ml
index e591aa4..6c1f250 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -1,12 +1,86 @@
 open Ast
 
-let _ =
-  try
-    let oi = open_in "test.node" in
-    let lexbuf = Lexing.from_channel oi in
-    let result = Parser.main Lexer.token lexbuf in
-    Format.printf "%a" Pp.pp_prog result;
-    close_in oi
-  with Lexer.Lexing_error s ->
-    Format.printf "Code d'erreur:\n\t%s\n\n" s
+let exit_error (s: string) : unit =
+  Format.printf "\n\tCritical error: %s\n\n" s
+
+let print_debug d s =
+  if d then Format.printf "\x1b[31;01;04mDebug :\x1b[0m %s\n" s else ()
+
+let print_verbose v s =
+  if v then Format.printf "\x1b[33;01;04mStatus:\x1b[0m %s\n" s else ()
+
+(** The following function should check whether the program is well-formed, by
+  * induction:
+  *  - for any applications of the form (n, arg1, ..., argn)
+  *    + n exists
+  *    + n waits n arguments
+  *    + arg1, ..., argn sont bien formés
+  *  - The expressions are well-typed
+  *  - The equations are well typed
+  *  - The output is set
+  *)
+let check_well_formedness (a: p_prog) = Some a
+let check_dependencies (a: p_prog) = Some a
+let simplify_prog (a: p_prog) = Some a
+
+let run verbose debug (passes: (p_prog -> p_prog option) list)
+  = verbose "kjlksjf"
+
+let _ =
+  (** Usage and argument parsing. *)
+  let default_passes = ["check_form"; "check_dependencies"; "simplify_prog"] in
+  let usage_msg = "Usage: main [-passes p1,...,pn] [-ast] [-verbose] [-debug] [-o output_file] source_file" in
+  let verbose = ref false in
+  let debug = ref false in
+  let ppast = ref false in
+  let passes = ref [] in
+  let source_file = ref "" in
+  let output_file = ref "out.c" in
+  let anon_fun filename = source_file := filename in
+  let speclist =
+    [
+      ("-ast", Arg.Set ppast, "Only print the AST of the input file");
+      ("-verbose", Arg.Set verbose, "Output some debug information");
+      ("-debug", Arg.Set debug, "Output a lot of debug information");
+      ("-p", Arg.String (fun s -> passes := s :: !passes),
+            "Add a pass to the compilation process");
+      ("-o", Arg.Set_string output_file, "Output file (defaults to [out.c])");
+    ] in
+  Arg.parse speclist anon_fun usage_msg ;
+  if !source_file = "" then exit_error "No source file specified" else
+  if !passes = [] then passes := default_passes;
+  let print_verbose = print_verbose !verbose in
+  let print_debug = print_debug !verbose in
+
+  (** Definition of the passes table *)
+  let passes_table : (string,  p_prog -> p_prog option) Hashtbl.t = Hashtbl.create 100 in
+  List.iter (fun (s, k) -> Hashtbl.add passes_table s k)
+    [
+      ("check_form", check_well_formedness);
+      ("check_dependencies", check_dependencies);
+      ("simplify_prog", simplify_prog);
+    ];
+
+  (** Main functionnalyty below *)
+  print_verbose "Parsing the source file...";
+  let ast =
+    try
+      begin
+      let inchan = open_in !source_file in
+      let res = Parser.main Lexer.token (Lexing.from_channel inchan) in
+      close_in inchan; res
+      end
+    with Lexer.Lexing_error s ->
+      exit_error (Format.sprintf "Code d'erreur:\n\t%s\n\n" s); exit 0 in
+
+  if !ppast then Format.printf "%a" Pp.pp_prog ast
+  else
+    let passes = List.map (fun (pass: string) ->
+      match Hashtbl.find_opt passes_table pass with
+      | None ->
+        (exit_error (Format.sprintf "The pass %s does not exist." pass); exit 0)
+      | Some f ->
+        (print_debug ("The pass "^pass^" has been selected."); f)) !passes in
+    run print_verbose print_debug passes;
+    print_verbose "End of the program, exiting gracefully."