--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+include "static_2/static/lsuba_aaa.ma".
+
+(* RESTRICTED REFINEMENT FOR ATOMIC ARITY ASSIGNMENT ************************)
+
+(* Main properties **********************************************************)
+
+theorem lsuba_trans: ∀G. Transitive … (lsuba G).
+#G #L1 #L #H elim H -L1 -L
+[ #X #H >(lsuba_inv_atom1 … H) -H //
+| #I #L1 #L #HL1 #IHL1 #Y #H
+ elim (lsuba_inv_bind1 … H) -H * #L2
+ [ #HL2 #H destruct /3 width=1 by lsuba_bind/
+ | #W #V #A #HV #HW #HL2 #H1 #H2 destruct
+ /3 width=3 by lsuba_beta, lsuba_aaa_trans/
+ ]
+| #L1 #L #W #V #A #HV #HW #HL1 #IHL1 #Y #H
+ elim (lsuba_inv_bind1 … H) -H * #L2
+ [ #HL2 #H destruct /3 width=5 by lsuba_beta, lsuba_aaa_conf/
+ | #W0 #V0 #A0 #_ #_ #_ #H destruct
+ ]
+]
+qed-.