--- /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 "NTrack/defs.ma".
+(*
+theorem ntrack_inv_lref: \forall Q,S,i. NTrack Q (lref i) S \to
+ \exists P. Insert S i P Q.
+ intros; inversion H; clear H; intros; destruct; autobatch.
+qed.
+
+theorem ntrack_inv_parx: \forall P,S,h. NTrack P (parx h) S \to
+ S = pair (posr h) (posr h).
+ intros; inversion H; clear H; intros; destruct; autobatch.
+qed.
+
+theorem ntrack_inv_impw: \forall P,p,S. NTrack P (impw p) S \to
+ \exists B,a,b.
+ S = pair (impl a b) B \land
+ NTrack P p (pair lleaf B).
+ intros; inversion H; clear H; intros; destruct; autobatch depth = 5.
+qed.
+
+theorem ntrack_inv_impr: \forall P,p,S. NTrack P (impr p) S \to
+ \exists a,b:Formula.
+ S = pair lleaf (impl a b) \land
+ NTrack P p (pair a b).
+ intros; inversion H; clear H; intros; destruct; autobatch depth = 4.
+qed.
+
+theorem ntrack_inv_impi: \forall P,p,q,r,S. NTrack P (impi p q r) S \to
+ \exists Q,A,B,D,i. \exists a,b:Formula.
+ S = pair (impl a b) D \land
+ NTrack P p (pair A a) \land
+ NTrack P q (pair b B) \land
+ NTrack Q r (pair lleaf D) \land
+ Insert (pair A B) i P Q.
+ intros; inversion H; clear H; intros; destruct; autobatch depth = 12 width = 5 size = 16.
+qed.
+
+theorem ntrack_inv_scut: \forall P,q,r,S. NTrack P (scut q r) S \to False.
+ intros; inversion H; clear H; intros; destruct.
+qed.
+
+theorem ntrack_inv_lleaf_impl:
+ \forall Q,p,a,b. NTrack Q p (pair lleaf (impl a b)) \to
+ (\exists P,i. p = lref i \land Insert (pair lleaf (impl a b)) i P Q) \lor
+ (\exists r. p = impr r \land NTrack Q r (pair a b)).
+ intros; inversion H; clear H; intros; destruct;
+ [ autobatch depth = 5
+ | destruct; autobatch depth = 4
+ ].
+qed.
+*)