(* ------------------------------------------------------------- *)

Lemma multipar_Abs_exists: ∀ x (G : context) D rho (a a' : tm),
lc_tm (a_UAbs rho a) -> x `notin` fv_tm_tm_tm a
→ multipar G D (open_tm_wrt_tm a (a_Var_f x)) a'
→ multipar G D (a_UAbs rho a) (a_UAbs rho (close_tm_wrt_tm x a')).