How fib is compiled in OCaml, and a hand compilation of it to Elisp

gistfile1.txt

let rec fib = function   | 0 -> 0   | 1 -> 1   | n -> fib (n-1) + fib (n-2)

(* Output of -dlambda *)

(setglobal Fib!
  (letrec
    (fib/1008
       (function n/1009
         (if (!= n/1009 0)
           (if (!= n/1009 1)
             (+ (apply fib/1008 (- n/1009 1)) (apply fib/1008 (- n/1009 2)))
             1)
           0)))
    (makeblock 0 fib/1008)))

(* Actual OCaml data of lambda *)

Lprim
  (Psetglobal ("Fib_0"),
   [ Lletrec
       ([ ("fib_1008",
           Lfunction
             (Curried, [ "n_1009" ],
              Lifthenelse
                (Lprim
                   (Pintcomp (Cneq),
                    [ Lvar ("n_1009"); Lconst (Const_base (Const_int (0))) ]),
                 Lifthenelse
                   (Lprim
                      (Pintcomp (Cneq),
                       [ Lvar ("n_1009"); Lconst (Const_base (Const_int (1))) ]),
                    Lprim
                      (Paddint,
                       [ Lapply
                           (Lvar ("fib_1008"),
                            [ Lprim
                                (Psubint,
                                 [ Lvar ("n_1009");
                                   Lconst (Const_base (Const_int (1))) ]) ],
                            "File \"fib.ml\", line 4, characters 9-18");
                         Lapply
                           (Lvar ("fib_1008"),
                            [ Lprim
                                (Psubint,
                                 [ Lvar ("n_1009");
                                   Lconst (Const_base (Const_int (2))) ]) ],
                            "File \"fib.ml\", line 4, characters 21-30") ]),
                    Lconst (Const_base (Const_int (1)))),
                 Lconst (Const_base (Const_int (0)))))) ],
        Lprim (Pmakeblock (0, Immutable), [ Lvar ("fib_1008") ])) ])

(* Hand compilation to Elisp *)

(setq fib/1008 (lambda (n/1009)
  (if (not (equal n/1009 0))
    (if (not (equal n/1009 1))
      (+ (funcall fib/1008 (- n/1009 1))
        (funcall fib/1008 (- n/1009 2)))
      1)
  0)))

(defun fib/1008/f (n) (funcall fib/1008 n))

(fib/1008/f 10)