assumption.
qed.
+(* guarded troppo debole
+theorem test5: nat → ∃n. 1 ≤ n.
+apply (
+ let rec aux n : nat ≝
+ match n with
+ [ O ⇒ 1
+ | S m ⇒ S (aux m)
+ ]
+ in
+ aux
+: nat → ∃n. 1 ≤ n);
+cases name_con;
+simplify;
+ [ autobatch
+ | cases (aux n);
+ simplify;
+ apply lt_O_S
+ ]
+qed.
+*)
+
+(*
+theorem test5: nat → ∃n. 1 ≤ n.
+apply (
+ let rec aux (n : nat) : ∃n. 1 ≤ n ≝
+ match n with
+ [ O => (S O : ∃n. 1 ≤ n)
+ | S m => (S (aux m) : ∃n. 1 ≤ n)
+(*
+ inject ? (S (eject ? (aux m))) ? *)
+ ]
+ in
+ aux
+ : nat → ∃n. 1 ≤ n);
+ [ autobatch
+ | elim (aux m);
+ simplify;
+ autobatch
+ ]
+qed.
+
+Re1: nat => nat |- body[Rel1] : nat => nat
+Re1: nat => X |- body[Rel1] : nat => nat : nat => X
+Re1: Y => X |- body[Rel1] : nat => nat : Y => X
+
+nat => nat
+nat => X
+
+theorem test5: (∃n. 2 ≤ n) → ∃n. 1 ≤ n.
+apply (
+ λk: ∃n. 2 ≤ n.
+ let rec aux n : eject ? n = eject ? k → ∃n. 1 ≤ n ≝
+ match eject ? n return λx:nat. x = eject ? k → ∃n. 1 ≤ n with
+ [ O ⇒ λH: 0 = eject ? k.
+ sigma_intro ? ? 0 ?
+ | S m ⇒ λH: S m = eject ? k.
+ sigma_intro ? ? (S m) ?
+ ]
+ in
+ aux k (refl_eq ? (eject ? k)));
+
+
+intro;
+cases s; clear s;
+generalize in match H; clear H;
+elim a;
+ [ apply (sigma_intro ? ? 0);
+ | apply (sigma_intro ? ? (S n));
+ ].
+
+apply (
+ λk.
+ let rec aux n : ∃n. 1 ≤ n ≝
+ inject ?
+ (match n with
+ [ O ⇒ O
+ | S m ⇒ S (eject ? (aux m))
+ ]) ?
+ in aux (eject ? k)).
+
+
+apply (
+ let rec aux n : nat ≝
+ match n with
+ [ O ⇒ O
+ | S m ⇒ S (aux m)
+ ]
+ in
+ aux
+: (∃n. 2 ≤ n) → ∃n. 1 ≤ n);
+
+qed.
+
(*
theorem test5: nat → ∃n. 0 ≤ n.
apply (λn:nat.?);
autobatch.
qed.
*)
+*)
\ No newline at end of file