Hint Resolve multipar_context_independent.

Lemma multipar_App_destruct_Irrel : forall S D a1 c,
multipar S D (a_App a1 Irrel a_Bullet) c ->
(exists a1',
multipar S D (a_App a1 Irrel a_Bullet) (a_App (a_UAbs Irrel a1') Irrel a_Bullet) /\
multipar S D a1 (a_UAbs Irrel a1') /\ multipar S D (open_tm_wrt_tm a1' a_Bullet) c) \/
(exists a1',
multipar S D (a_App a1 Irrel a_Bullet) (a_App a1' Irrel a_Bullet) /\
multipar S D a1 a1').