(* Note: crux of the proof begins *)
@(stream_eq_trans … (tr_compose_uni_dx_pap …)) <tr_pap_succ_nap
@tr_compose_eq_repl // >nsucc_unfold
(* Note: crux of the proof begins *)
@(stream_eq_trans … (tr_compose_uni_dx_pap …)) <tr_pap_succ_nap
@tr_compose_eq_repl // >nsucc_unfold