(** Out preserves gHalfA *)

(* Specifications: *)
Lemma ghalfa_out4__ghalfa : forall A B C D E F A' C' D' F',
Out B A' A -> Out B C' C -> Out E D' D -> Out E F' F -> gHalfA A B C D E F ->
gHalfA A' B C' D' E F'.