let rec delay exp_faust = match exp_faust with
        |Const v        ->        0
        |Ident s        ->
                (
                        match s with
                        |Add                        ->        0
                        |Sup                        ->        0                
                        |Mul                        ->        0
                        |Div                        ->        0
                        |Pass                        ->        0
                        |Stop                        ->        0
                        |Mem                        ->        1
                        |Delay                        ->        100000 (* danger! *)
                        |Floor                        ->        0
                        |Int                        ->        0
                        |Sin                        ->        0
                        |Cos                        ->        0
                        |Atan                        ->        0
                        |Atantwo                ->      0
                        |Sqrt                        ->        0
                        |Rdtable                ->        100000 (* danger! *)
                        |Mod                        ->        0
                        |Larger                        ->        0
                        |Smaller                ->        0
                        |Vectorize                ->        100 (* danger! *)
                        |Concat                        ->        0
                        |Nth                        ->        0
                        |Serialize                ->        0
                        |Prefix                         ->        1
                        |Selecttwo                ->        0
                        |Selectthree                ->        0
                )
        |Par (e1, e2)        ->        max (delay e1) (delay e2)
        |Seq (e1, e2)        ->        (delay e1) + (delay e2)
        |Split (e1, e2)        ->        (delay e1) + (delay e2)
        |Merge (e1, e2)        ->        (delay e1) + (delay e2)
        |Rec (e1, e2)        ->        delay e1