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(* as published by the Free Software Foundation; either version 2.1   *)
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(* GNU General Public License for more details.                       *)
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(* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA *)
(* 02110-1301 USA                                                     *)
(* correction de l'invariant de compatibilité par rapport à une signature *)

Lemma inter_correct_wrt_sign_invar :
forall (d0 d1 : DTA) (sigma : signature),
dta_correct_wrt_sign d0 sigma ->
dta_correct_wrt_sign d1 sigma -> dta_correct_wrt_sign (inter d0 d1) sigma.