(*  a -->  b -->* c    d - by prior lemma |      |      |    e - by induction. v      v      v *      *      * a2 --> d -->* e  *)

Lemma multipar_lc2: forall G D a1 a2, lc_tm a1 -> multipar G D a1 a2 -> lc_tm a2.
induction 2; eauto.