intros.
elim (EXPH4 (seq (ia Frame s3 lce) (K i))).
elim Lmers3.
elim LmerTnd.
elim LmerL.
elim LmerRn.
elim CommLRn.
elim CommTn_dL.
elim CommTn_dRn.
elim Comms3Tn_d.
elim Comms3L.
elim Comms3Rn_lce.
repeat elim A6'.
repeat elim A6.
elim SC7.
elim A5.
apply refl_equal.
Qed.

Theorem Lem16 :
forall d : D,
seq (ia Frame c3 (Tuple e1 d))
(enc H
(mer (K i)
(mer (seq (ia D s4 d) (seq (ia frame s5 (tuple e1)) (R i)))
(mer (seq (Tn_d d e1) (S i)) (L i))))) =
enc H
(mer (seq (ia Frame s3 (Tuple e1 d)) (K i))
(mer (seq (Tn_d d e1) (S i)) (mer (L i) (seq (Rn e0) (R i))))).