Proof using overlay_map_congr new_msg_map_congr name_map_bijective multi_map_congr fail_msg_map_congr.
move => net failed tr H_step.
remember step_ordered_dynamic_failure_init as y in *.
change failed with (fst (failed, net)).
change net with (snd (failed, net)) at 2.
move: Heqy.
induction H_step using refl_trans_1n_trace_n1_ind => H_init /=.
rewrite H_init /step_ordered_dynamic_failure_init /= /step_ordered_failure_init.
exact: RT1nTBase.
concludes.
repeat find_rewrite.
destruct x'.
destruct x''.
rewrite /=.
find_apply_lem_hyp step_ordered_dynamic_failure_pt_mapped_simulation_1; last by move: H_step1; apply: ordered_dynamic_nodes_no_dup.
simpl in *.
rewrite filterMap_app.
case: H => H.
have H_trans := refl_trans_1n_trace_trans IHH_step1.
apply: H_trans.
rewrite (app_nil_end (filterMap pt_map_trace_ev _)).
apply: (@RT1nTStep _ _ _ _ (map tot_map_name l0, pt_map_odnet o0)) => //.
exact: RT1nTBase.
move: H => [H_eq_n [H_eq_f H_eq]].
by rewrite H_eq_n -H_eq_f H_eq -app_nil_end.
Qed.

Lemma in_msg_filterMap_pt_map_msg :
forall l m' m0,
pt_map_msg m0 = Some m' ->
In m0 l ->
In m' (filterMap pt_map_msg l).