intros.
elim (EXPH4 (seq (Tn_d d e1) (S i))).
elim LmerTnd.
elim LmerL.
elim A4.
elim A5.
elim A5.
elim Lmeri.
elim LmerRn.
elim CommLRn.
elim CommiL.
elim CommiRn.
elim CommTn_dL.
elim CommTn_di.
elim CommTn_dRn.
repeat elim A6.
repeat elim A6'.
apply refl_equal.
Qed.

Theorem Lem15 :
forall d : D,
seq (ia Frame c3 lce)
(enc H
(mer (K i)
(mer (seq (ia frame s5 (tuple e0)) (seq (Rn e0) (R i)))
(mer (seq (Tn_d d e1) (S i)) (L i))))) =
enc H
(mer (seq (ia Frame s3 lce) (K i))
(mer (seq (Tn_d d e1) (S i)) (mer (L i) (seq (Rn e0) (R i))))).