--- /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 *)
+(* *)
+(**************************************************************************)
+
+(* This file was automatically generated: do not edit *********************)
+
+set "baseuri" "cic:/matita/LAMBDA-TYPES/Base-1/ext/arith".
+
+include "preamble.ma".
+
+theorem nat_dec:
+ \forall (n1: nat).(\forall (n2: nat).(or (eq nat n1 n2) ((eq nat n1 n2) \to
+(\forall (P: Prop).P))))
+\def
+ \lambda (n1: nat).(nat_ind (\lambda (n: nat).(\forall (n2: nat).(or (eq nat
+n n2) ((eq nat n n2) \to (\forall (P: Prop).P))))) (\lambda (n2:
+nat).(nat_ind (\lambda (n: nat).(or (eq nat O n) ((eq nat O n) \to (\forall
+(P: Prop).P)))) (or_introl (eq nat O O) ((eq nat O O) \to (\forall (P:
+Prop).P)) (refl_equal nat O)) (\lambda (n: nat).(\lambda (_: (or (eq nat O n)
+((eq nat O n) \to (\forall (P: Prop).P)))).(or_intror (eq nat O (S n)) ((eq
+nat O (S n)) \to (\forall (P: Prop).P)) (\lambda (H0: (eq nat O (S
+n))).(\lambda (P: Prop).(let H1 \def (eq_ind nat O (\lambda (ee: nat).(match
+ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow True | (S _)
+\Rightarrow False])) I (S n) H0) in (False_ind P H1))))))) n2)) (\lambda (n:
+nat).(\lambda (H: ((\forall (n2: nat).(or (eq nat n n2) ((eq nat n n2) \to
+(\forall (P: Prop).P)))))).(\lambda (n2: nat).(nat_ind (\lambda (n0: nat).(or
+(eq nat (S n) n0) ((eq nat (S n) n0) \to (\forall (P: Prop).P)))) (or_intror
+(eq nat (S n) O) ((eq nat (S n) O) \to (\forall (P: Prop).P)) (\lambda (H0:
+(eq nat (S n) O)).(\lambda (P: Prop).(let H1 \def (eq_ind nat (S n) (\lambda
+(ee: nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow
+False | (S _) \Rightarrow True])) I O H0) in (False_ind P H1))))) (\lambda
+(n0: nat).(\lambda (H0: (or (eq nat (S n) n0) ((eq nat (S n) n0) \to (\forall
+(P: Prop).P)))).(or_ind (eq nat n n0) ((eq nat n n0) \to (\forall (P:
+Prop).P)) (or (eq nat (S n) (S n0)) ((eq nat (S n) (S n0)) \to (\forall (P:
+Prop).P))) (\lambda (H1: (eq nat n n0)).(let H2 \def (eq_ind_r nat n0
+(\lambda (n3: nat).(or (eq nat (S n) n3) ((eq nat (S n) n3) \to (\forall (P:
+Prop).P)))) H0 n H1) in (eq_ind nat n (\lambda (n3: nat).(or (eq nat (S n) (S
+n3)) ((eq nat (S n) (S n3)) \to (\forall (P: Prop).P)))) (or_introl (eq nat
+(S n) (S n)) ((eq nat (S n) (S n)) \to (\forall (P: Prop).P)) (refl_equal nat
+(S n))) n0 H1))) (\lambda (H1: (((eq nat n n0) \to (\forall (P:
+Prop).P)))).(or_intror (eq nat (S n) (S n0)) ((eq nat (S n) (S n0)) \to
+(\forall (P: Prop).P)) (\lambda (H2: (eq nat (S n) (S n0))).(\lambda (P:
+Prop).(let H3 \def (f_equal nat nat (\lambda (e: nat).(match e in nat return
+(\lambda (_: nat).nat) with [O \Rightarrow n | (S n3) \Rightarrow n3])) (S n)
+(S n0) H2) in (let H4 \def (eq_ind_r nat n0 (\lambda (n3: nat).((eq nat n n3)
+\to (\forall (P0: Prop).P0))) H1 n H3) in (let H5 \def (eq_ind_r nat n0
+(\lambda (n3: nat).(or (eq nat (S n) n3) ((eq nat (S n) n3) \to (\forall (P0:
+Prop).P0)))) H0 n H3) in (H4 (refl_equal nat n) P)))))))) (H n0)))) n2))))
+n1).
+
+theorem simpl_plus_r:
+ \forall (n: nat).(\forall (m: nat).(\forall (p: nat).((eq nat (plus m n)
+(plus p n)) \to (eq nat m p))))
+\def
+ \lambda (n: nat).(\lambda (m: nat).(\lambda (p: nat).(\lambda (H: (eq nat
+(plus m n) (plus p n))).(plus_reg_l n m p (eq_ind_r nat (plus m n) (\lambda
+(n0: nat).(eq nat n0 (plus n p))) (eq_ind_r nat (plus p n) (\lambda (n0:
+nat).(eq nat n0 (plus n p))) (sym_eq nat (plus n p) (plus p n) (plus_comm n
+p)) (plus m n) H) (plus n m) (plus_comm n m)))))).
+
+theorem minus_plus_r:
+ \forall (m: nat).(\forall (n: nat).(eq nat (minus (plus m n) n) m))
+\def
+ \lambda (m: nat).(\lambda (n: nat).(eq_ind_r nat (plus n m) (\lambda (n0:
+nat).(eq nat (minus n0 n) m)) (minus_plus n m) (plus m n) (plus_comm m n))).
+
+theorem plus_permute_2_in_3:
+ \forall (x: nat).(\forall (y: nat).(\forall (z: nat).(eq nat (plus (plus x
+y) z) (plus (plus x z) y))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (z: nat).(eq_ind_r nat (plus x
+(plus y z)) (\lambda (n: nat).(eq nat n (plus (plus x z) y))) (eq_ind_r nat
+(plus z y) (\lambda (n: nat).(eq nat (plus x n) (plus (plus x z) y))) (eq_ind
+nat (plus (plus x z) y) (\lambda (n: nat).(eq nat n (plus (plus x z) y)))
+(refl_equal nat (plus (plus x z) y)) (plus x (plus z y)) (plus_assoc_reverse
+x z y)) (plus y z) (plus_comm y z)) (plus (plus x y) z) (plus_assoc_reverse x
+y z)))).
+
+theorem plus_permute_2_in_3_assoc:
+ \forall (n: nat).(\forall (h: nat).(\forall (k: nat).(eq nat (plus (plus n
+h) k) (plus n (plus k h)))))
+\def
+ \lambda (n: nat).(\lambda (h: nat).(\lambda (k: nat).(eq_ind_r nat (plus
+(plus n k) h) (\lambda (n0: nat).(eq nat n0 (plus n (plus k h)))) (eq_ind_r
+nat (plus (plus n k) h) (\lambda (n0: nat).(eq nat (plus (plus n k) h) n0))
+(refl_equal nat (plus (plus n k) h)) (plus n (plus k h)) (plus_assoc n k h))
+(plus (plus n h) k) (plus_permute_2_in_3 n h k)))).
+
+theorem plus_O:
+ \forall (x: nat).(\forall (y: nat).((eq nat (plus x y) O) \to (land (eq nat
+x O) (eq nat y O))))
+\def
+ \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((eq nat (plus
+n y) O) \to (land (eq nat n O) (eq nat y O))))) (\lambda (y: nat).(\lambda
+(H: (eq nat (plus O y) O)).(conj (eq nat O O) (eq nat y O) (refl_equal nat O)
+H))) (\lambda (n: nat).(\lambda (_: ((\forall (y: nat).((eq nat (plus n y) O)
+\to (land (eq nat n O) (eq nat y O)))))).(\lambda (y: nat).(\lambda (H0: (eq
+nat (plus (S n) y) O)).(let H1 \def (match H0 in eq return (\lambda (n0:
+nat).(\lambda (_: (eq ? ? n0)).((eq nat n0 O) \to (land (eq nat (S n) O) (eq
+nat y O))))) with [refl_equal \Rightarrow (\lambda (H1: (eq nat (plus (S n)
+y) O)).(let H2 \def (eq_ind nat (plus (S n) y) (\lambda (e: nat).(match e in
+nat return (\lambda (_: nat).Prop) with [O \Rightarrow False | (S _)
+\Rightarrow True])) I O H1) in (False_ind (land (eq nat (S n) O) (eq nat y
+O)) H2)))]) in (H1 (refl_equal nat O))))))) x).
+
+theorem minus_Sx_SO:
+ \forall (x: nat).(eq nat (minus (S x) (S O)) x)
+\def
+ \lambda (x: nat).(eq_ind nat x (\lambda (n: nat).(eq nat n x)) (refl_equal
+nat x) (minus x O) (minus_n_O x)).
+
+theorem eq_nat_dec:
+ \forall (i: nat).(\forall (j: nat).(or (not (eq nat i j)) (eq nat i j)))
+\def
+ \lambda (i: nat).(nat_ind (\lambda (n: nat).(\forall (j: nat).(or (not (eq
+nat n j)) (eq nat n j)))) (\lambda (j: nat).(nat_ind (\lambda (n: nat).(or
+(not (eq nat O n)) (eq nat O n))) (or_intror (not (eq nat O O)) (eq nat O O)
+(refl_equal nat O)) (\lambda (n: nat).(\lambda (_: (or (not (eq nat O n)) (eq
+nat O n))).(or_introl (not (eq nat O (S n))) (eq nat O (S n)) (O_S n)))) j))
+(\lambda (n: nat).(\lambda (H: ((\forall (j: nat).(or (not (eq nat n j)) (eq
+nat n j))))).(\lambda (j: nat).(nat_ind (\lambda (n0: nat).(or (not (eq nat
+(S n) n0)) (eq nat (S n) n0))) (or_introl (not (eq nat (S n) O)) (eq nat (S
+n) O) (sym_not_eq nat O (S n) (O_S n))) (\lambda (n0: nat).(\lambda (_: (or
+(not (eq nat (S n) n0)) (eq nat (S n) n0))).(or_ind (not (eq nat n n0)) (eq
+nat n n0) (or (not (eq nat (S n) (S n0))) (eq nat (S n) (S n0))) (\lambda
+(H1: (not (eq nat n n0))).(or_introl (not (eq nat (S n) (S n0))) (eq nat (S
+n) (S n0)) (not_eq_S n n0 H1))) (\lambda (H1: (eq nat n n0)).(or_intror (not
+(eq nat (S n) (S n0))) (eq nat (S n) (S n0)) (f_equal nat nat S n n0 H1))) (H
+n0)))) j)))) i).
+
+theorem neq_eq_e:
+ \forall (i: nat).(\forall (j: nat).(\forall (P: Prop).((((not (eq nat i j))
+\to P)) \to ((((eq nat i j) \to P)) \to P))))
+\def
+ \lambda (i: nat).(\lambda (j: nat).(\lambda (P: Prop).(\lambda (H: (((not
+(eq nat i j)) \to P))).(\lambda (H0: (((eq nat i j) \to P))).(let o \def
+(eq_nat_dec i j) in (or_ind (not (eq nat i j)) (eq nat i j) P H H0 o)))))).
+
+theorem le_false:
+ \forall (m: nat).(\forall (n: nat).(\forall (P: Prop).((le m n) \to ((le (S
+n) m) \to P))))
+\def
+ \lambda (m: nat).(nat_ind (\lambda (n: nat).(\forall (n0: nat).(\forall (P:
+Prop).((le n n0) \to ((le (S n0) n) \to P))))) (\lambda (n: nat).(\lambda (P:
+Prop).(\lambda (_: (le O n)).(\lambda (H0: (le (S n) O)).(let H1 \def (match
+H0 in le return (\lambda (n0: nat).(\lambda (_: (le ? n0)).((eq nat n0 O) \to
+P))) with [le_n \Rightarrow (\lambda (H1: (eq nat (S n) O)).(let H2 \def
+(eq_ind nat (S n) (\lambda (e: nat).(match e in nat return (\lambda (_:
+nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow True])) I O H1) in
+(False_ind P H2))) | (le_S m0 H1) \Rightarrow (\lambda (H2: (eq nat (S m0)
+O)).((let H3 \def (eq_ind nat (S m0) (\lambda (e: nat).(match e in nat return
+(\lambda (_: nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow True]))
+I O H2) in (False_ind ((le (S n) m0) \to P) H3)) H1))]) in (H1 (refl_equal
+nat O))))))) (\lambda (n: nat).(\lambda (H: ((\forall (n0: nat).(\forall (P:
+Prop).((le n n0) \to ((le (S n0) n) \to P)))))).(\lambda (n0: nat).(nat_ind
+(\lambda (n1: nat).(\forall (P: Prop).((le (S n) n1) \to ((le (S n1) (S n))
+\to P)))) (\lambda (P: Prop).(\lambda (H0: (le (S n) O)).(\lambda (_: (le (S
+O) (S n))).(let H2 \def (match H0 in le return (\lambda (n1: nat).(\lambda
+(_: (le ? n1)).((eq nat n1 O) \to P))) with [le_n \Rightarrow (\lambda (H2:
+(eq nat (S n) O)).(let H3 \def (eq_ind nat (S n) (\lambda (e: nat).(match e
+in nat return (\lambda (_: nat).Prop) with [O \Rightarrow False | (S _)
+\Rightarrow True])) I O H2) in (False_ind P H3))) | (le_S m0 H2) \Rightarrow
+(\lambda (H3: (eq nat (S m0) O)).((let H4 \def (eq_ind nat (S m0) (\lambda
+(e: nat).(match e in nat return (\lambda (_: nat).Prop) with [O \Rightarrow
+False | (S _) \Rightarrow True])) I O H3) in (False_ind ((le (S n) m0) \to P)
+H4)) H2))]) in (H2 (refl_equal nat O)))))) (\lambda (n1: nat).(\lambda (_:
+((\forall (P: Prop).((le (S n) n1) \to ((le (S n1) (S n)) \to P))))).(\lambda
+(P: Prop).(\lambda (H1: (le (S n) (S n1))).(\lambda (H2: (le (S (S n1)) (S
+n))).(H n1 P (le_S_n n n1 H1) (le_S_n (S n1) n H2))))))) n0)))) m).
+
+theorem le_Sx_x:
+ \forall (x: nat).((le (S x) x) \to (\forall (P: Prop).P))
+\def
+ \lambda (x: nat).(\lambda (H: (le (S x) x)).(\lambda (P: Prop).(let H0 \def
+le_Sn_n in (False_ind P (H0 x H))))).
+
+theorem minus_le:
+ \forall (x: nat).(\forall (y: nat).(le (minus x y) x))
+\def
+ \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).(le (minus n
+y) n))) (\lambda (_: nat).(le_n O)) (\lambda (n: nat).(\lambda (H: ((\forall
+(y: nat).(le (minus n y) n)))).(\lambda (y: nat).(nat_ind (\lambda (n0:
+nat).(le (minus (S n) n0) (S n))) (le_n (S n)) (\lambda (n0: nat).(\lambda
+(_: (le (match n0 with [O \Rightarrow (S n) | (S l) \Rightarrow (minus n l)])
+(S n))).(le_S (minus n n0) n (H n0)))) y)))) x).
+
+theorem le_plus_minus_sym:
+ \forall (n: nat).(\forall (m: nat).((le n m) \to (eq nat m (plus (minus m n)
+n))))
+\def
+ \lambda (n: nat).(\lambda (m: nat).(\lambda (H: (le n m)).(eq_ind_r nat
+(plus n (minus m n)) (\lambda (n0: nat).(eq nat m n0)) (le_plus_minus n m H)
+(plus (minus m n) n) (plus_comm (minus m n) n)))).
+
+theorem le_minus_minus:
+ \forall (x: nat).(\forall (y: nat).((le x y) \to (\forall (z: nat).((le y z)
+\to (le (minus y x) (minus z x))))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (le x y)).(\lambda (z:
+nat).(\lambda (H0: (le y z)).(plus_le_reg_l x (minus y x) (minus z x)
+(eq_ind_r nat y (\lambda (n: nat).(le n (plus x (minus z x)))) (eq_ind_r nat
+z (\lambda (n: nat).(le y n)) H0 (plus x (minus z x)) (le_plus_minus_r x z
+(le_trans x y z H H0))) (plus x (minus y x)) (le_plus_minus_r x y H))))))).
+
+theorem le_minus_plus:
+ \forall (z: nat).(\forall (x: nat).((le z x) \to (\forall (y: nat).(eq nat
+(minus (plus x y) z) (plus (minus x z) y)))))
+\def
+ \lambda (z: nat).(nat_ind (\lambda (n: nat).(\forall (x: nat).((le n x) \to
+(\forall (y: nat).(eq nat (minus (plus x y) n) (plus (minus x n) y))))))
+(\lambda (x: nat).(\lambda (H: (le O x)).(let H0 \def (match H in le return
+(\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n x) \to (\forall (y:
+nat).(eq nat (minus (plus x y) O) (plus (minus x O) y)))))) with [le_n
+\Rightarrow (\lambda (H0: (eq nat O x)).(eq_ind nat O (\lambda (n:
+nat).(\forall (y: nat).(eq nat (minus (plus n y) O) (plus (minus n O) y))))
+(\lambda (y: nat).(sym_eq nat (plus (minus O O) y) (minus (plus O y) O)
+(minus_n_O (plus O y)))) x H0)) | (le_S m H0) \Rightarrow (\lambda (H1: (eq
+nat (S m) x)).(eq_ind nat (S m) (\lambda (n: nat).((le O m) \to (\forall (y:
+nat).(eq nat (minus (plus n y) O) (plus (minus n O) y))))) (\lambda (_: (le O
+m)).(\lambda (y: nat).(refl_equal nat (plus (minus (S m) O) y)))) x H1 H0))])
+in (H0 (refl_equal nat x))))) (\lambda (z0: nat).(\lambda (H: ((\forall (x:
+nat).((le z0 x) \to (\forall (y: nat).(eq nat (minus (plus x y) z0) (plus
+(minus x z0) y))))))).(\lambda (x: nat).(nat_ind (\lambda (n: nat).((le (S
+z0) n) \to (\forall (y: nat).(eq nat (minus (plus n y) (S z0)) (plus (minus n
+(S z0)) y))))) (\lambda (H0: (le (S z0) O)).(\lambda (y: nat).(let H1 \def
+(match H0 in le return (\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n O)
+\to (eq nat (minus (plus O y) (S z0)) (plus (minus O (S z0)) y))))) with
+[le_n \Rightarrow (\lambda (H1: (eq nat (S z0) O)).(let H2 \def (eq_ind nat
+(S z0) (\lambda (e: nat).(match e in nat return (\lambda (_: nat).Prop) with
+[O \Rightarrow False | (S _) \Rightarrow True])) I O H1) in (False_ind (eq
+nat (minus (plus O y) (S z0)) (plus (minus O (S z0)) y)) H2))) | (le_S m H1)
+\Rightarrow (\lambda (H2: (eq nat (S m) O)).((let H3 \def (eq_ind nat (S m)
+(\lambda (e: nat).(match e in nat return (\lambda (_: nat).Prop) with [O
+\Rightarrow False | (S _) \Rightarrow True])) I O H2) in (False_ind ((le (S
+z0) m) \to (eq nat (minus (plus O y) (S z0)) (plus (minus O (S z0)) y))) H3))
+H1))]) in (H1 (refl_equal nat O))))) (\lambda (n: nat).(\lambda (_: (((le (S
+z0) n) \to (\forall (y: nat).(eq nat (minus (plus n y) (S z0)) (plus (minus n
+(S z0)) y)))))).(\lambda (H1: (le (S z0) (S n))).(\lambda (y: nat).(H n
+(le_S_n z0 n H1) y))))) x)))) z).
+
+theorem le_minus:
+ \forall (x: nat).(\forall (z: nat).(\forall (y: nat).((le (plus x y) z) \to
+(le x (minus z y)))))
+\def
+ \lambda (x: nat).(\lambda (z: nat).(\lambda (y: nat).(\lambda (H: (le (plus
+x y) z)).(eq_ind nat (minus (plus x y) y) (\lambda (n: nat).(le n (minus z
+y))) (le_minus_minus y (plus x y) (le_plus_r x y) z H) x (minus_plus_r x
+y))))).
+
+theorem le_trans_plus_r:
+ \forall (x: nat).(\forall (y: nat).(\forall (z: nat).((le (plus x y) z) \to
+(le y z))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (z: nat).(\lambda (H: (le (plus
+x y) z)).(le_trans y (plus x y) z (le_plus_r x y) H)))).
+
+theorem le_gen_S:
+ \forall (m: nat).(\forall (x: nat).((le (S m) x) \to (ex2 nat (\lambda (n:
+nat).(eq nat x (S n))) (\lambda (n: nat).(le m n)))))
+\def
+ \lambda (m: nat).(\lambda (x: nat).(\lambda (H: (le (S m) x)).(let H0 \def
+(match H in le return (\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n x)
+\to (ex2 nat (\lambda (n0: nat).(eq nat x (S n0))) (\lambda (n0: nat).(le m
+n0)))))) with [le_n \Rightarrow (\lambda (H0: (eq nat (S m) x)).(eq_ind nat
+(S m) (\lambda (n: nat).(ex2 nat (\lambda (n0: nat).(eq nat n (S n0)))
+(\lambda (n0: nat).(le m n0)))) (ex_intro2 nat (\lambda (n: nat).(eq nat (S
+m) (S n))) (\lambda (n: nat).(le m n)) m (refl_equal nat (S m)) (le_n m)) x
+H0)) | (le_S m0 H0) \Rightarrow (\lambda (H1: (eq nat (S m0) x)).(eq_ind nat
+(S m0) (\lambda (n: nat).((le (S m) m0) \to (ex2 nat (\lambda (n0: nat).(eq
+nat n (S n0))) (\lambda (n0: nat).(le m n0))))) (\lambda (H2: (le (S m)
+m0)).(ex_intro2 nat (\lambda (n: nat).(eq nat (S m0) (S n))) (\lambda (n:
+nat).(le m n)) m0 (refl_equal nat (S m0)) (le_S_n m m0 (le_S (S m) m0 H2))))
+x H1 H0))]) in (H0 (refl_equal nat x))))).
+
+theorem lt_x_plus_x_Sy:
+ \forall (x: nat).(\forall (y: nat).(lt x (plus x (S y))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(eq_ind_r nat (plus (S y) x) (\lambda (n:
+nat).(lt x n)) (le_S_n (S x) (S (plus y x)) (le_n_S (S x) (S (plus y x))
+(le_n_S x (plus y x) (le_plus_r y x)))) (plus x (S y)) (plus_comm x (S y)))).
+
+theorem simpl_lt_plus_r:
+ \forall (p: nat).(\forall (n: nat).(\forall (m: nat).((lt (plus n p) (plus m
+p)) \to (lt n m))))
+\def
+ \lambda (p: nat).(\lambda (n: nat).(\lambda (m: nat).(\lambda (H: (lt (plus
+n p) (plus m p))).(plus_lt_reg_l n m p (let H0 \def (eq_ind nat (plus n p)
+(\lambda (n0: nat).(lt n0 (plus m p))) H (plus p n) (plus_comm n p)) in (let
+H1 \def (eq_ind nat (plus m p) (\lambda (n0: nat).(lt (plus p n) n0)) H0
+(plus p m) (plus_comm m p)) in H1)))))).
+
+theorem minus_x_Sy:
+ \forall (x: nat).(\forall (y: nat).((lt y x) \to (eq nat (minus x y) (S
+(minus x (S y))))))
+\def
+ \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((lt y n) \to
+(eq nat (minus n y) (S (minus n (S y))))))) (\lambda (y: nat).(\lambda (H:
+(lt y O)).(let H0 \def (match H in le return (\lambda (n: nat).(\lambda (_:
+(le ? n)).((eq nat n O) \to (eq nat (minus O y) (S (minus O (S y))))))) with
+[le_n \Rightarrow (\lambda (H0: (eq nat (S y) O)).(let H1 \def (eq_ind nat (S
+y) (\lambda (e: nat).(match e in nat return (\lambda (_: nat).Prop) with [O
+\Rightarrow False | (S _) \Rightarrow True])) I O H0) in (False_ind (eq nat
+(minus O y) (S (minus O (S y)))) H1))) | (le_S m H0) \Rightarrow (\lambda
+(H1: (eq nat (S m) O)).((let H2 \def (eq_ind nat (S m) (\lambda (e:
+nat).(match e in nat return (\lambda (_: nat).Prop) with [O \Rightarrow False
+| (S _) \Rightarrow True])) I O H1) in (False_ind ((le (S y) m) \to (eq nat
+(minus O y) (S (minus O (S y))))) H2)) H0))]) in (H0 (refl_equal nat O)))))
+(\lambda (n: nat).(\lambda (H: ((\forall (y: nat).((lt y n) \to (eq nat
+(minus n y) (S (minus n (S y)))))))).(\lambda (y: nat).(nat_ind (\lambda (n0:
+nat).((lt n0 (S n)) \to (eq nat (minus (S n) n0) (S (minus (S n) (S n0))))))
+(\lambda (_: (lt O (S n))).(eq_ind nat n (\lambda (n0: nat).(eq nat (S n) (S
+n0))) (refl_equal nat (S n)) (minus n O) (minus_n_O n))) (\lambda (n0:
+nat).(\lambda (_: (((lt n0 (S n)) \to (eq nat (minus (S n) n0) (S (minus (S
+n) (S n0))))))).(\lambda (H1: (lt (S n0) (S n))).(let H2 \def (le_S_n (S n0)
+n H1) in (H n0 H2))))) y)))) x).
+
+theorem lt_plus_minus:
+ \forall (x: nat).(\forall (y: nat).((lt x y) \to (eq nat y (S (plus x (minus
+y (S x)))))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(le_plus_minus (S
+x) y H))).
+
+theorem lt_plus_minus_r:
+ \forall (x: nat).(\forall (y: nat).((lt x y) \to (eq nat y (S (plus (minus y
+(S x)) x)))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(eq_ind_r nat
+(plus x (minus y (S x))) (\lambda (n: nat).(eq nat y (S n))) (lt_plus_minus x
+y H) (plus (minus y (S x)) x) (plus_comm (minus y (S x)) x)))).
+
+theorem minus_x_SO:
+ \forall (x: nat).((lt O x) \to (eq nat x (S (minus x (S O)))))
+\def
+ \lambda (x: nat).(\lambda (H: (lt O x)).(eq_ind nat (minus x O) (\lambda (n:
+nat).(eq nat x n)) (eq_ind nat x (\lambda (n: nat).(eq nat x n)) (refl_equal
+nat x) (minus x O) (minus_n_O x)) (S (minus x (S O))) (minus_x_Sy x O H))).
+
+theorem le_x_pred_y:
+ \forall (y: nat).(\forall (x: nat).((lt x y) \to (le x (pred y))))
+\def
+ \lambda (y: nat).(nat_ind (\lambda (n: nat).(\forall (x: nat).((lt x n) \to
+(le x (pred n))))) (\lambda (x: nat).(\lambda (H: (lt x O)).(let H0 \def
+(match H in le return (\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n O)
+\to (le x O)))) with [le_n \Rightarrow (\lambda (H0: (eq nat (S x) O)).(let
+H1 \def (eq_ind nat (S x) (\lambda (e: nat).(match e in nat return (\lambda
+(_: nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow True])) I O H0)
+in (False_ind (le x O) H1))) | (le_S m H0) \Rightarrow (\lambda (H1: (eq nat
+(S m) O)).((let H2 \def (eq_ind nat (S m) (\lambda (e: nat).(match e in nat
+return (\lambda (_: nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow
+True])) I O H1) in (False_ind ((le (S x) m) \to (le x O)) H2)) H0))]) in (H0
+(refl_equal nat O))))) (\lambda (n: nat).(\lambda (_: ((\forall (x: nat).((lt
+x n) \to (le x (pred n)))))).(\lambda (x: nat).(\lambda (H0: (lt x (S
+n))).(le_S_n x n H0))))) y).
+
+theorem lt_le_minus:
+ \forall (x: nat).(\forall (y: nat).((lt x y) \to (le x (minus y (S O)))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(le_minus x y (S
+O) (eq_ind_r nat (plus (S O) x) (\lambda (n: nat).(le n y)) H (plus x (S O))
+(plus_comm x (S O)))))).
+
+theorem lt_le_e:
+ \forall (n: nat).(\forall (d: nat).(\forall (P: Prop).((((lt n d) \to P))
+\to ((((le d n) \to P)) \to P))))
+\def
+ \lambda (n: nat).(\lambda (d: nat).(\lambda (P: Prop).(\lambda (H: (((lt n
+d) \to P))).(\lambda (H0: (((le d n) \to P))).(let H1 \def (le_or_lt d n) in
+(or_ind (le d n) (lt n d) P H0 H H1)))))).
+
+theorem lt_eq_e:
+ \forall (x: nat).(\forall (y: nat).(\forall (P: Prop).((((lt x y) \to P))
+\to ((((eq nat x y) \to P)) \to ((le x y) \to P)))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (P: Prop).(\lambda (H: (((lt x
+y) \to P))).(\lambda (H0: (((eq nat x y) \to P))).(\lambda (H1: (le x
+y)).(or_ind (lt x y) (eq nat x y) P H H0 (le_lt_or_eq x y H1))))))).
+
+theorem lt_eq_gt_e:
+ \forall (x: nat).(\forall (y: nat).(\forall (P: Prop).((((lt x y) \to P))
+\to ((((eq nat x y) \to P)) \to ((((lt y x) \to P)) \to P)))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (P: Prop).(\lambda (H: (((lt x
+y) \to P))).(\lambda (H0: (((eq nat x y) \to P))).(\lambda (H1: (((lt y x)
+\to P))).(lt_le_e x y P H (\lambda (H2: (le y x)).(lt_eq_e y x P H1 (\lambda
+(H3: (eq nat y x)).(H0 (sym_eq nat y x H3))) H2)))))))).
+
+theorem lt_gen_xS:
+ \forall (x: nat).(\forall (n: nat).((lt x (S n)) \to (or (eq nat x O) (ex2
+nat (\lambda (m: nat).(eq nat x (S m))) (\lambda (m: nat).(lt m n))))))
+\def
+ \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (n0: nat).((lt n (S
+n0)) \to (or (eq nat n O) (ex2 nat (\lambda (m: nat).(eq nat n (S m)))
+(\lambda (m: nat).(lt m n0))))))) (\lambda (n: nat).(\lambda (_: (lt O (S
+n))).(or_introl (eq nat O O) (ex2 nat (\lambda (m: nat).(eq nat O (S m)))
+(\lambda (m: nat).(lt m n))) (refl_equal nat O)))) (\lambda (n: nat).(\lambda
+(_: ((\forall (n0: nat).((lt n (S n0)) \to (or (eq nat n O) (ex2 nat (\lambda
+(m: nat).(eq nat n (S m))) (\lambda (m: nat).(lt m n0)))))))).(\lambda (n0:
+nat).(\lambda (H0: (lt (S n) (S n0))).(or_intror (eq nat (S n) O) (ex2 nat
+(\lambda (m: nat).(eq nat (S n) (S m))) (\lambda (m: nat).(lt m n0)))
+(ex_intro2 nat (\lambda (m: nat).(eq nat (S n) (S m))) (\lambda (m: nat).(lt
+m n0)) n (refl_equal nat (S n)) (le_S_n (S n) n0 H0))))))) x).
+
+theorem le_lt_false:
+ \forall (x: nat).(\forall (y: nat).((le x y) \to ((lt y x) \to (\forall (P:
+Prop).P))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (le x y)).(\lambda (H0: (lt
+y x)).(\lambda (P: Prop).(False_ind P (le_not_lt x y H H0)))))).
+
+theorem lt_neq:
+ \forall (x: nat).(\forall (y: nat).((lt x y) \to (not (eq nat x y))))
+\def
+ \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(\lambda (H0: (eq
+nat x y)).(let H1 \def (eq_ind nat x (\lambda (n: nat).(lt n y)) H y H0) in
+(lt_irrefl y H1))))).
+
+theorem arith0:
+ \forall (h2: nat).(\forall (d2: nat).(\forall (n: nat).((le (plus d2 h2) n)
+\to (\forall (h1: nat).(le (plus d2 h1) (minus (plus n h1) h2))))))
+\def
+ \lambda (h2: nat).(\lambda (d2: nat).(\lambda (n: nat).(\lambda (H: (le
+(plus d2 h2) n)).(\lambda (h1: nat).(eq_ind nat (minus (plus h2 (plus d2 h1))
+h2) (\lambda (n0: nat).(le n0 (minus (plus n h1) h2))) (le_minus_minus h2
+(plus h2 (plus d2 h1)) (le_plus_l h2 (plus d2 h1)) (plus n h1) (eq_ind_r nat
+(plus (plus h2 d2) h1) (\lambda (n0: nat).(le n0 (plus n h1))) (eq_ind_r nat
+(plus d2 h2) (\lambda (n0: nat).(le (plus n0 h1) (plus n h1))) (le_S_n (plus
+(plus d2 h2) h1) (plus n h1) (lt_le_S (plus (plus d2 h2) h1) (S (plus n h1))
+(le_lt_n_Sm (plus (plus d2 h2) h1) (plus n h1) (plus_le_compat (plus d2 h2) n
+h1 h1 H (le_n h1))))) (plus h2 d2) (plus_comm h2 d2)) (plus h2 (plus d2 h1))
+(plus_assoc h2 d2 h1))) (plus d2 h1) (minus_plus h2 (plus d2 h1))))))).
+
+theorem O_minus:
+ \forall (x: nat).(\forall (y: nat).((le x y) \to (eq nat (minus x y) O)))
+\def
+ \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((le n y) \to
+(eq nat (minus n y) O)))) (\lambda (y: nat).(\lambda (_: (le O
+y)).(refl_equal nat O))) (\lambda (x0: nat).(\lambda (H: ((\forall (y:
+nat).((le x0 y) \to (eq nat (minus x0 y) O))))).(\lambda (y: nat).(nat_ind
+(\lambda (n: nat).((le (S x0) n) \to (eq nat (match n with [O \Rightarrow (S
+x0) | (S l) \Rightarrow (minus x0 l)]) O))) (\lambda (H0: (le (S x0)
+O)).(ex2_ind nat (\lambda (n: nat).(eq nat O (S n))) (\lambda (n: nat).(le x0
+n)) (eq nat (S x0) O) (\lambda (x1: nat).(\lambda (H1: (eq nat O (S
+x1))).(\lambda (_: (le x0 x1)).(let H3 \def (eq_ind nat O (\lambda (ee:
+nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow True
+| (S _) \Rightarrow False])) I (S x1) H1) in (False_ind (eq nat (S x0) O)
+H3))))) (le_gen_S x0 O H0))) (\lambda (n: nat).(\lambda (_: (((le (S x0) n)
+\to (eq nat (match n with [O \Rightarrow (S x0) | (S l) \Rightarrow (minus x0
+l)]) O)))).(\lambda (H1: (le (S x0) (S n))).(H n (le_S_n x0 n H1))))) y))))
+x).
+
+theorem minus_minus:
+ \forall (z: nat).(\forall (x: nat).(\forall (y: nat).((le z x) \to ((le z y)
+\to ((eq nat (minus x z) (minus y z)) \to (eq nat x y))))))
+\def
+ \lambda (z: nat).(nat_ind (\lambda (n: nat).(\forall (x: nat).(\forall (y:
+nat).((le n x) \to ((le n y) \to ((eq nat (minus x n) (minus y n)) \to (eq
+nat x y))))))) (\lambda (x: nat).(\lambda (y: nat).(\lambda (_: (le O
+x)).(\lambda (_: (le O y)).(\lambda (H1: (eq nat (minus x O) (minus y
+O))).(let H2 \def (eq_ind_r nat (minus x O) (\lambda (n: nat).(eq nat n
+(minus y O))) H1 x (minus_n_O x)) in (let H3 \def (eq_ind_r nat (minus y O)
+(\lambda (n: nat).(eq nat x n)) H2 y (minus_n_O y)) in H3))))))) (\lambda
+(z0: nat).(\lambda (IH: ((\forall (x: nat).(\forall (y: nat).((le z0 x) \to
+((le z0 y) \to ((eq nat (minus x z0) (minus y z0)) \to (eq nat x
+y)))))))).(\lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((le
+(S z0) n) \to ((le (S z0) y) \to ((eq nat (minus n (S z0)) (minus y (S z0)))
+\to (eq nat n y)))))) (\lambda (y: nat).(\lambda (H: (le (S z0) O)).(\lambda
+(_: (le (S z0) y)).(\lambda (_: (eq nat (minus O (S z0)) (minus y (S
+z0)))).(ex2_ind nat (\lambda (n: nat).(eq nat O (S n))) (\lambda (n: nat).(le
+z0 n)) (eq nat O y) (\lambda (x0: nat).(\lambda (H2: (eq nat O (S
+x0))).(\lambda (_: (le z0 x0)).(let H4 \def (eq_ind nat O (\lambda (ee:
+nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow True
+| (S _) \Rightarrow False])) I (S x0) H2) in (False_ind (eq nat O y) H4)))))
+(le_gen_S z0 O H)))))) (\lambda (x0: nat).(\lambda (_: ((\forall (y:
+nat).((le (S z0) x0) \to ((le (S z0) y) \to ((eq nat (minus x0 (S z0)) (minus
+y (S z0))) \to (eq nat x0 y))))))).(\lambda (y: nat).(nat_ind (\lambda (n:
+nat).((le (S z0) (S x0)) \to ((le (S z0) n) \to ((eq nat (minus (S x0) (S
+z0)) (minus n (S z0))) \to (eq nat (S x0) n))))) (\lambda (_: (le (S z0) (S
+x0))).(\lambda (H0: (le (S z0) O)).(\lambda (_: (eq nat (minus (S x0) (S z0))
+(minus O (S z0)))).(ex2_ind nat (\lambda (n: nat).(eq nat O (S n))) (\lambda
+(n: nat).(le z0 n)) (eq nat (S x0) O) (\lambda (x1: nat).(\lambda (H2: (eq
+nat O (S x1))).(\lambda (_: (le z0 x1)).(let H4 \def (eq_ind nat O (\lambda
+(ee: nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow
+True | (S _) \Rightarrow False])) I (S x1) H2) in (False_ind (eq nat (S x0)
+O) H4))))) (le_gen_S z0 O H0))))) (\lambda (y0: nat).(\lambda (_: (((le (S
+z0) (S x0)) \to ((le (S z0) y0) \to ((eq nat (minus (S x0) (S z0)) (minus y0
+(S z0))) \to (eq nat (S x0) y0)))))).(\lambda (H: (le (S z0) (S
+x0))).(\lambda (H0: (le (S z0) (S y0))).(\lambda (H1: (eq nat (minus (S x0)
+(S z0)) (minus (S y0) (S z0)))).(f_equal nat nat S x0 y0 (IH x0 y0 (le_S_n z0
+x0 H) (le_S_n z0 y0 H0) H1))))))) y)))) x)))) z).
+
+theorem plus_plus:
+ \forall (z: nat).(\forall (x1: nat).(\forall (x2: nat).(\forall (y1:
+nat).(\forall (y2: nat).((le x1 z) \to ((le x2 z) \to ((eq nat (plus (minus z
+x1) y1) (plus (minus z x2) y2)) \to (eq nat (plus x1 y2) (plus x2 y1)))))))))
+\def
+ \lambda (z: nat).(nat_ind (\lambda (n: nat).(\forall (x1: nat).(\forall (x2:
+nat).(\forall (y1: nat).(\forall (y2: nat).((le x1 n) \to ((le x2 n) \to ((eq
+nat (plus (minus n x1) y1) (plus (minus n x2) y2)) \to (eq nat (plus x1 y2)
+(plus x2 y1)))))))))) (\lambda (x1: nat).(\lambda (x2: nat).(\lambda (y1:
+nat).(\lambda (y2: nat).(\lambda (H: (le x1 O)).(\lambda (H0: (le x2
+O)).(\lambda (H1: (eq nat y1 y2)).(eq_ind nat y1 (\lambda (n: nat).(eq nat
+(plus x1 n) (plus x2 y1))) (let H_y \def (le_n_O_eq x2 H0) in (eq_ind nat O
+(\lambda (n: nat).(eq nat (plus x1 y1) (plus n y1))) (let H_y0 \def
+(le_n_O_eq x1 H) in (eq_ind nat O (\lambda (n: nat).(eq nat (plus n y1) (plus
+O y1))) (refl_equal nat (plus O y1)) x1 H_y0)) x2 H_y)) y2 H1))))))))
+(\lambda (z0: nat).(\lambda (IH: ((\forall (x1: nat).(\forall (x2:
+nat).(\forall (y1: nat).(\forall (y2: nat).((le x1 z0) \to ((le x2 z0) \to
+((eq nat (plus (minus z0 x1) y1) (plus (minus z0 x2) y2)) \to (eq nat (plus
+x1 y2) (plus x2 y1))))))))))).(\lambda (x1: nat).(nat_ind (\lambda (n:
+nat).(\forall (x2: nat).(\forall (y1: nat).(\forall (y2: nat).((le n (S z0))
+\to ((le x2 (S z0)) \to ((eq nat (plus (minus (S z0) n) y1) (plus (minus (S
+z0) x2) y2)) \to (eq nat (plus n y2) (plus x2 y1))))))))) (\lambda (x2:
+nat).(nat_ind (\lambda (n: nat).(\forall (y1: nat).(\forall (y2: nat).((le O
+(S z0)) \to ((le n (S z0)) \to ((eq nat (plus (minus (S z0) O) y1) (plus
+(minus (S z0) n) y2)) \to (eq nat (plus O y2) (plus n y1)))))))) (\lambda
+(y1: nat).(\lambda (y2: nat).(\lambda (_: (le O (S z0))).(\lambda (_: (le O
+(S z0))).(\lambda (H1: (eq nat (S (plus z0 y1)) (S (plus z0 y2)))).(let H_y
+\def (IH O O) in (let H2 \def (eq_ind_r nat (minus z0 O) (\lambda (n:
+nat).(\forall (y3: nat).(\forall (y4: nat).((le O z0) \to ((le O z0) \to ((eq
+nat (plus n y3) (plus n y4)) \to (eq nat y4 y3))))))) H_y z0 (minus_n_O z0))
+in (H2 y1 y2 (le_O_n z0) (le_O_n z0) (H2 (plus z0 y2) (plus z0 y1) (le_O_n
+z0) (le_O_n z0) (f_equal nat nat (plus z0) (plus z0 y2) (plus z0 y1) (sym_eq
+nat (plus z0 y1) (plus z0 y2) (eq_add_S (plus z0 y1) (plus z0 y2)
+H1)))))))))))) (\lambda (x3: nat).(\lambda (_: ((\forall (y1: nat).(\forall
+(y2: nat).((le O (S z0)) \to ((le x3 (S z0)) \to ((eq nat (S (plus z0 y1))
+(plus (match x3 with [O \Rightarrow (S z0) | (S l) \Rightarrow (minus z0 l)])
+y2)) \to (eq nat y2 (plus x3 y1))))))))).(\lambda (y1: nat).(\lambda (y2:
+nat).(\lambda (_: (le O (S z0))).(\lambda (H0: (le (S x3) (S z0))).(\lambda
+(H1: (eq nat (S (plus z0 y1)) (plus (minus z0 x3) y2))).(let H_y \def (IH O
+x3 (S y1)) in (let H2 \def (eq_ind_r nat (minus z0 O) (\lambda (n:
+nat).(\forall (y3: nat).((le O z0) \to ((le x3 z0) \to ((eq nat (plus n (S
+y1)) (plus (minus z0 x3) y3)) \to (eq nat y3 (plus x3 (S y1)))))))) H_y z0
+(minus_n_O z0)) in (let H3 \def (eq_ind_r nat (plus z0 (S y1)) (\lambda (n:
+nat).(\forall (y3: nat).((le O z0) \to ((le x3 z0) \to ((eq nat n (plus
+(minus z0 x3) y3)) \to (eq nat y3 (plus x3 (S y1)))))))) H2 (S (plus z0 y1))
+(plus_n_Sm z0 y1)) in (let H4 \def (eq_ind_r nat (plus x3 (S y1)) (\lambda
+(n: nat).(\forall (y3: nat).((le O z0) \to ((le x3 z0) \to ((eq nat (S (plus
+z0 y1)) (plus (minus z0 x3) y3)) \to (eq nat y3 n)))))) H3 (S (plus x3 y1))
+(plus_n_Sm x3 y1)) in (H4 y2 (le_O_n z0) (le_S_n x3 z0 H0) H1))))))))))))
+x2)) (\lambda (x2: nat).(\lambda (_: ((\forall (x3: nat).(\forall (y1:
+nat).(\forall (y2: nat).((le x2 (S z0)) \to ((le x3 (S z0)) \to ((eq nat
+(plus (minus (S z0) x2) y1) (plus (minus (S z0) x3) y2)) \to (eq nat (plus x2
+y2) (plus x3 y1)))))))))).(\lambda (x3: nat).(nat_ind (\lambda (n:
+nat).(\forall (y1: nat).(\forall (y2: nat).((le (S x2) (S z0)) \to ((le n (S
+z0)) \to ((eq nat (plus (minus (S z0) (S x2)) y1) (plus (minus (S z0) n) y2))
+\to (eq nat (plus (S x2) y2) (plus n y1)))))))) (\lambda (y1: nat).(\lambda
+(y2: nat).(\lambda (H: (le (S x2) (S z0))).(\lambda (_: (le O (S
+z0))).(\lambda (H1: (eq nat (plus (minus z0 x2) y1) (S (plus z0 y2)))).(let
+H_y \def (IH x2 O y1 (S y2)) in (let H2 \def (eq_ind_r nat (minus z0 O)
+(\lambda (n: nat).((le x2 z0) \to ((le O z0) \to ((eq nat (plus (minus z0 x2)
+y1) (plus n (S y2))) \to (eq nat (plus x2 (S y2)) y1))))) H_y z0 (minus_n_O
+z0)) in (let H3 \def (eq_ind_r nat (plus z0 (S y2)) (\lambda (n: nat).((le x2
+z0) \to ((le O z0) \to ((eq nat (plus (minus z0 x2) y1) n) \to (eq nat (plus
+x2 (S y2)) y1))))) H2 (S (plus z0 y2)) (plus_n_Sm z0 y2)) in (let H4 \def
+(eq_ind_r nat (plus x2 (S y2)) (\lambda (n: nat).((le x2 z0) \to ((le O z0)
+\to ((eq nat (plus (minus z0 x2) y1) (S (plus z0 y2))) \to (eq nat n y1)))))
+H3 (S (plus x2 y2)) (plus_n_Sm x2 y2)) in (H4 (le_S_n x2 z0 H) (le_O_n z0)
+H1)))))))))) (\lambda (x4: nat).(\lambda (_: ((\forall (y1: nat).(\forall
+(y2: nat).((le (S x2) (S z0)) \to ((le x4 (S z0)) \to ((eq nat (plus (minus
+z0 x2) y1) (plus (match x4 with [O \Rightarrow (S z0) | (S l) \Rightarrow
+(minus z0 l)]) y2)) \to (eq nat (S (plus x2 y2)) (plus x4
+y1))))))))).(\lambda (y1: nat).(\lambda (y2: nat).(\lambda (H: (le (S x2) (S
+z0))).(\lambda (H0: (le (S x4) (S z0))).(\lambda (H1: (eq nat (plus (minus z0
+x2) y1) (plus (minus z0 x4) y2))).(f_equal nat nat S (plus x2 y2) (plus x4
+y1) (IH x2 x4 y1 y2 (le_S_n x2 z0 H) (le_S_n x4 z0 H0) H1))))))))) x3))))
+x1)))) z).
+
+theorem le_S_minus:
+ \forall (d: nat).(\forall (h: nat).(\forall (n: nat).((le (plus d h) n) \to
+(le d (S (minus n h))))))
+\def
+ \lambda (d: nat).(\lambda (h: nat).(\lambda (n: nat).(\lambda (H: (le (plus
+d h) n)).(let H0 \def (le_trans d (plus d h) n (le_plus_l d h) H) in (let H1
+\def (eq_ind nat n (\lambda (n0: nat).(le d n0)) H0 (plus (minus n h) h)
+(le_plus_minus_sym h n (le_trans_plus_r d h n H))) in (le_S d (minus n h)
+(le_minus d n h H))))))).
+
--- /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 *)
+(* *)
+(**************************************************************************)
+
+set "baseuri" "cic:/matita/LAMBDA-TYPES/Base-1/preamble".
+
+include' "../../../../legacy/coq.ma".
+
+(* FG: This is because "and" is a reserved keyword of the parser *)
+alias id "land" = "cic:/Coq/Init/Logic/and.ind#xpointer(1/1)".
+
+(* FG/CSC: These aliases should disappear: we would like to write something
+ * like: "disambiguate in cic:/Coq/*"
+ *)
+alias symbol "plus" = "Coq's natural plus".
+alias symbol "leq" = "Coq's natural 'less or equal to'".
+alias symbol "neq" = "Coq's not equal to (leibnitz)".
+alias symbol "eq" = "Coq's leibnitz's equality".
+
+alias id "bool" = "cic:/Coq/Init/Datatypes/bool.ind#xpointer(1/1)".
+alias id "conj" = "cic:/Coq/Init/Logic/and.ind#xpointer(1/1/1)".
+alias id "eq_add_S" = "cic:/Coq/Init/Peano/eq_add_S.con".
+alias id "eq" = "cic:/Coq/Init/Logic/eq.ind#xpointer(1/1)".
+alias id "eq_ind" = "cic:/Coq/Init/Logic/eq_ind.con".
+alias id "eq_ind_r" = "cic:/Coq/Init/Logic/eq_ind_r.con".
+alias id "ex2" = "cic:/Coq/Init/Logic/ex2.ind#xpointer(1/1)".
+alias id "ex2_ind" = "cic:/Coq/Init/Logic/ex2_ind.con".
+alias id "ex" = "cic:/Coq/Init/Logic/ex.ind#xpointer(1/1)".
+alias id "ex_intro2" = "cic:/Coq/Init/Logic/ex2.ind#xpointer(1/1/1)".
+alias id "false" = "cic:/Coq/Init/Datatypes/bool.ind#xpointer(1/1/2)".
+alias id "False" = "cic:/Coq/Init/Logic/False.ind#xpointer(1/1)".
+alias id "False_ind" = "cic:/Coq/Init/Logic/False_ind.con".
+alias id "I" = "cic:/Coq/Init/Logic/True.ind#xpointer(1/1/1)".
+alias id "le_antisym" = "cic:/Coq/Arith/Le/le_antisym.con".
+alias id "le" = "cic:/Coq/Init/Peano/le.ind#xpointer(1/1)".
+alias id "le_lt_n_Sm" = "cic:/Coq/Arith/Lt/le_lt_n_Sm.con".
+alias id "le_lt_or_eq" = "cic:/Coq/Arith/Lt/le_lt_or_eq.con".
+alias id "le_n" = "cic:/Coq/Init/Peano/le.ind#xpointer(1/1/1)".
+alias id "le_n_O_eq" = "cic:/Coq/Arith/Le/le_n_O_eq.con".
+alias id "le_not_lt" = "cic:/Coq/Arith/Lt/le_not_lt.con".
+alias id "le_n_S" = "cic:/Coq/Arith/Le/le_n_S.con".
+alias id "le_O_n" = "cic:/Coq/Arith/Le/le_O_n.con".
+alias id "le_or_lt" = "cic:/Coq/Arith/Lt/le_or_lt.con".
+alias id "le_plus_l" = "cic:/Coq/Arith/Plus/le_plus_l.con".
+alias id "le_plus_minus" = "cic:/Coq/Arith/Minus/le_plus_minus.con".
+alias id "le_plus_minus_r" = "cic:/Coq/Arith/Minus/le_plus_minus_r.con".
+alias id "le_plus_r" = "cic:/Coq/Arith/Plus/le_plus_r.con".
+alias id "le_S" = "cic:/Coq/Init/Peano/le.ind#xpointer(1/1/2)".
+alias id "le_S_n" = "cic:/Coq/Arith/Le/le_S_n.con".
+alias id "le_Sn_n" = "cic:/Coq/Arith/Le/le_Sn_n.con".
+alias id "le_trans" = "cic:/Coq/Arith/Le/le_trans.con".
+alias id "lt" = "cic:/Coq/Init/Peano/lt.con".
+alias id "lt_irrefl" = "cic:/Coq/Arith/Lt/lt_irrefl.con".
+alias id "lt_le_S" = "cic:/Coq/Arith/Lt/lt_le_S.con".
+alias id "lt_n_S" = "cic:/Coq/Arith/Lt/lt_n_S.con".
+alias id "minus" = "cic:/Coq/Init/Peano/minus.con".
+alias id "minus_n_O" = "cic:/Coq/Arith/Minus/minus_n_O.con".
+alias id "minus_plus" = "cic:/Coq/Arith/Minus/minus_plus.con".
+alias id "nat" = "cic:/Coq/Init/Datatypes/nat.ind#xpointer(1/1)".
+alias id "nat_ind" = "cic:/Coq/Init/Datatypes/nat_ind.con".
+alias id "not" = "cic:/Coq/Init/Logic/not.con".
+alias id "not_eq_S" = "cic:/Coq/Init/Peano/not_eq_S.con".
+alias id "O" = "cic:/Coq/Init/Datatypes/nat.ind#xpointer(1/1/1)".
+alias id "or" = "cic:/Coq/Init/Logic/or.ind#xpointer(1/1)".
+alias id "or_ind" = "cic:/Coq/Init/Logic/or_ind.con".
+alias id "or_introl" = "cic:/Coq/Init/Logic/or.ind#xpointer(1/1/1)".
+alias id "or_intror" = "cic:/Coq/Init/Logic/or.ind#xpointer(1/1/2)".
+alias id "O_S" = "cic:/Coq/Init/Peano/O_S.con".
+alias id "plus_assoc" = "cic:/Coq/Arith/Plus/plus_assoc.con".
+alias id "plus_assoc_reverse" = "cic:/Coq/Arith/Plus/plus_assoc_reverse.con".
+alias id "plus" = "cic:/Coq/Init/Peano/plus.con".
+alias id "plus_comm" = "cic:/Coq/Arith/Plus/plus_comm.con".
+alias id "plus_le_compat" = "cic:/Coq/Arith/Plus/plus_le_compat.con".
+alias id "plus_le_reg_l" = "cic:/Coq/Arith/Plus/plus_le_reg_l.con".
+alias id "plus_lt_reg_l" = "cic:/Coq/Arith/Plus/plus_lt_reg_l.con".
+alias id "plus_n_Sm" = "cic:/Coq/Init/Peano/plus_n_Sm.con".
+alias id "plus_reg_l" = "cic:/Coq/Arith/Plus/plus_reg_l.con".
+alias id "pred" = "cic:/Coq/Init/Peano/pred.con".
+alias id "refl_equal" = "cic:/Coq/Init/Logic/eq.ind#xpointer(1/1/1)".
+alias id "S" = "cic:/Coq/Init/Datatypes/nat.ind#xpointer(1/1/2)".
+alias id "true" = "cic:/Coq/Init/Datatypes/bool.ind#xpointer(1/1/1)".
+alias id "True" = "cic:/Coq/Init/Logic/True.ind#xpointer(1/1)".
+alias id "plus_lt_compat_r" = "cic:/Coq/Arith/Plus/plus_lt_compat_r.con".
+alias id "plus_n_O" = "cic:/Coq/Init/Peano/plus_n_O.con".
+alias id "plus_le_lt_compat" = "cic:/Coq/Arith/Plus/plus_le_lt_compat.con".
+alias id "lt_wf_ind" = "cic:/Coq/Arith/Wf_nat/lt_wf_ind.con".
+alias id "minus_Sn_m" = "cic:/Coq/Arith/Minus/minus_Sn_m.con".
+alias id "and_ind" = "cic:/Coq/Init/Logic/and_ind.con".
+alias id "le_lt_trans" = "cic:/Coq/Arith/Lt/le_lt_trans.con".
+alias id "lt_le_trans" = "cic:/Coq/Arith/Lt/lt_le_trans.con".
+alias id "le_lt_trans" = "cic:/Coq/Arith/Lt/le_lt_trans.con".
+alias id "plus_n_O" = "cic:/Coq/Init/Peano/plus_n_O.con".
+alias id "f_equal3" = "cic:/Coq/Init/Logic/f_equal3.con".
+alias id "S_pred" = "cic:/Coq/Arith/Lt/S_pred.con".
+alias id "lt_le_trans" = "cic:/Coq/Arith/Lt/lt_le_trans.con".
+alias id "plus_lt_compat_r" = "cic:/Coq/Arith/Plus/plus_lt_compat_r.con".
+alias id "le_plus_trans" = "cic:/Coq/Arith/Plus/le_plus_trans.con".
+alias id "f_equal2" = "cic:/Coq/Init/Logic/f_equal2.con".
+alias id "le_plus_trans" = "cic:/Coq/Arith/Plus/le_plus_trans.con".
+alias id "f_equal2" = "cic:/Coq/Init/Logic/f_equal2.con".
+alias id "plus_n_O" = "cic:/Coq/Init/Peano/plus_n_O.con".
+alias id "plus_n_O" = "cic:/Coq/Init/Peano/plus_n_O.con".
+alias id "lt_trans" = "cic:/Coq/Arith/Lt/lt_trans.con".
+alias id "minus_Sn_m" = "cic:/Coq/Arith/Minus/minus_Sn_m.con".
+alias id "ex_intro" = "cic:/Coq/Init/Logic/ex.ind#xpointer(1/1/1)".
+alias id "lt_trans" = "cic:/Coq/Arith/Lt/lt_trans.con".
+alias id "lt_n_Sn" = "cic:/Coq/Arith/Lt/lt_n_Sn.con".
+alias id "lt_le_trans" = "cic:/Coq/Arith/Lt/lt_le_trans.con".
+alias id "lt_wf_ind" = "cic:/Coq/Arith/Wf_nat/lt_wf_ind.con".
+alias id "bool_ind" = "cic:/Coq/Init/Datatypes/bool_ind.con".
+alias id "ex_ind" = "cic:/Coq/Init/Logic/ex_ind.con".
+alias id "plus_Snm_nSm" = "cic:/Coq/Arith/Plus/plus_Snm_nSm.con".
+alias id "plus_lt_le_compat" = "cic:/Coq/Arith/Plus/plus_lt_le_compat.con".
+alias id "plus_lt_compat" = "cic:/Coq/Arith/Plus/plus_lt_compat.con".
+alias id "lt_S_n" = "cic:/Coq/Arith/Lt/lt_S_n.con".
+alias id "minus_n_n" = "cic:/Coq/Arith/Minus/minus_n_n.con".
+
+theorem f_equal: \forall A,B:Type. \forall f:A \to B.
+ \forall x,y:A. x = y \to f x = f y.
+ intros. elim H. reflexivity.
+qed.
+
+theorem sym_eq: \forall A:Type. \forall x,y:A. x = y \to y = x.
+ intros. rewrite > H. reflexivity.
+qed.
+
+theorem sym_not_eq: \forall A:Type. \forall x,y:A. x \neq y \to y \neq x.
+ unfold not. intros. apply H. symmetry. assumption.
+qed.
+
+theorem trans_eq : \forall A:Type. \forall x,y,z:A. x=y \to y=z \to x=z.
+ intros. transitivity y; assumption.
+qed.
+
+theorem plus_reg_l: \forall n,m,p. n + m = n + p \to m = p.
+ intros. apply plus_reg_l; auto.
+qed.
+
+theorem plus_le_reg_l: \forall p,n,m. p + n <= p + m \to n <= m.
+ intros. apply plus_le_reg_l; auto.
+qed.
+
+default "equality"
+ cic:/Coq/Init/Logic/eq.ind
+ cic:/matita/LAMBDA-TYPES/Base-1/preamble/sym_eq.con
+ cic:/matita/LAMBDA-TYPES/Base-1/preamble/trans_eq.con
+ cic:/Coq/Init/Logic/eq_ind.con
+ cic:/Coq/Init/Logic/eq_ind_r.con
+ cic:/matita/LAMBDA-TYPES/Base-1/preamble/f_equal.con
+ cic:/matita/legacy/coq/f_equal1.con.
--- /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 *)
+(* *)
+(**************************************************************************)
+
+(* This file was automatically generated: do not edit *********************)
+
+set "baseuri" "cic:/matita/LAMBDA-TYPES/Base-1/types/defs".
+
+include "preamble.ma".
+
+inductive and3 (P0: Prop) (P1: Prop) (P2: Prop): Prop \def
+| and3_intro: P0 \to (P1 \to (P2 \to (and3 P0 P1 P2))).
+
+inductive or3 (P0: Prop) (P1: Prop) (P2: Prop): Prop \def
+| or3_intro0: P0 \to (or3 P0 P1 P2)
+| or3_intro1: P1 \to (or3 P0 P1 P2)
+| or3_intro2: P2 \to (or3 P0 P1 P2).
+
+inductive or4 (P0: Prop) (P1: Prop) (P2: Prop) (P3: Prop): Prop \def
+| or4_intro0: P0 \to (or4 P0 P1 P2 P3)
+| or4_intro1: P1 \to (or4 P0 P1 P2 P3)
+| or4_intro2: P2 \to (or4 P0 P1 P2 P3)
+| or4_intro3: P3 \to (or4 P0 P1 P2 P3).
+
+inductive ex3 (A0: Set) (P0: A0 \to Prop) (P1: A0 \to Prop) (P2: A0 \to
+Prop): Prop \def
+| ex3_intro: \forall (x0: A0).((P0 x0) \to ((P1 x0) \to ((P2 x0) \to (ex3 A0
+P0 P1 P2)))).
+
+inductive ex4 (A0: Set) (P0: A0 \to Prop) (P1: A0 \to Prop) (P2: A0 \to Prop)
+(P3: A0 \to Prop): Prop \def
+| ex4_intro: \forall (x0: A0).((P0 x0) \to ((P1 x0) \to ((P2 x0) \to ((P3 x0)
+\to (ex4 A0 P0 P1 P2 P3))))).
+
+inductive ex_2 (A0: Set) (A1: Set) (P0: A0 \to (A1 \to Prop)): Prop \def
+| ex_2_intro: \forall (x0: A0).(\forall (x1: A1).((P0 x0 x1) \to (ex_2 A0 A1
+P0))).
+
+inductive ex2_2 (A0: Set) (A1: Set) (P0: A0 \to (A1 \to Prop)) (P1: A0 \to
+(A1 \to Prop)): Prop \def
+| ex2_2_intro: \forall (x0: A0).(\forall (x1: A1).((P0 x0 x1) \to ((P1 x0 x1)
+\to (ex2_2 A0 A1 P0 P1)))).
+
+inductive ex3_2 (A0: Set) (A1: Set) (P0: A0 \to (A1 \to Prop)) (P1: A0 \to
+(A1 \to Prop)) (P2: A0 \to (A1 \to Prop)): Prop \def
+| ex3_2_intro: \forall (x0: A0).(\forall (x1: A1).((P0 x0 x1) \to ((P1 x0 x1)
+\to ((P2 x0 x1) \to (ex3_2 A0 A1 P0 P1 P2))))).
+
+inductive ex4_2 (A0: Set) (A1: Set) (P0: A0 \to (A1 \to Prop)) (P1: A0 \to
+(A1 \to Prop)) (P2: A0 \to (A1 \to Prop)) (P3: A0 \to (A1 \to Prop)): Prop
+\def
+| ex4_2_intro: \forall (x0: A0).(\forall (x1: A1).((P0 x0 x1) \to ((P1 x0 x1)
+\to ((P2 x0 x1) \to ((P3 x0 x1) \to (ex4_2 A0 A1 P0 P1 P2 P3)))))).
+
+inductive ex_3 (A0: Set) (A1: Set) (A2: Set) (P0: A0 \to (A1 \to (A2 \to
+Prop))): Prop \def
+| ex_3_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).((P0 x0 x1
+x2) \to (ex_3 A0 A1 A2 P0)))).
+
+inductive ex2_3 (A0: Set) (A1: Set) (A2: Set) (P0: A0 \to (A1 \to (A2 \to
+Prop))) (P1: A0 \to (A1 \to (A2 \to Prop))): Prop \def
+| ex2_3_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).((P0 x0
+x1 x2) \to ((P1 x0 x1 x2) \to (ex2_3 A0 A1 A2 P0 P1))))).
+
+inductive ex3_3 (A0: Set) (A1: Set) (A2: Set) (P0: A0 \to (A1 \to (A2 \to
+Prop))) (P1: A0 \to (A1 \to (A2 \to Prop))) (P2: A0 \to (A1 \to (A2 \to
+Prop))): Prop \def
+| ex3_3_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).((P0 x0
+x1 x2) \to ((P1 x0 x1 x2) \to ((P2 x0 x1 x2) \to (ex3_3 A0 A1 A2 P0 P1
+P2)))))).
+
+inductive ex4_3 (A0: Set) (A1: Set) (A2: Set) (P0: A0 \to (A1 \to (A2 \to
+Prop))) (P1: A0 \to (A1 \to (A2 \to Prop))) (P2: A0 \to (A1 \to (A2 \to
+Prop))) (P3: A0 \to (A1 \to (A2 \to Prop))): Prop \def
+| ex4_3_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).((P0 x0
+x1 x2) \to ((P1 x0 x1 x2) \to ((P2 x0 x1 x2) \to ((P3 x0 x1 x2) \to (ex4_3 A0
+A1 A2 P0 P1 P2 P3))))))).
+
+inductive ex3_4 (A0: Set) (A1: Set) (A2: Set) (A3: Set) (P0: A0 \to (A1 \to
+(A2 \to (A3 \to Prop)))) (P1: A0 \to (A1 \to (A2 \to (A3 \to Prop)))) (P2: A0
+\to (A1 \to (A2 \to (A3 \to Prop)))): Prop \def
+| ex3_4_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).(\forall
+(x3: A3).((P0 x0 x1 x2 x3) \to ((P1 x0 x1 x2 x3) \to ((P2 x0 x1 x2 x3) \to
+(ex3_4 A0 A1 A2 A3 P0 P1 P2))))))).
+
+inductive ex4_4 (A0: Set) (A1: Set) (A2: Set) (A3: Set) (P0: A0 \to (A1 \to
+(A2 \to (A3 \to Prop)))) (P1: A0 \to (A1 \to (A2 \to (A3 \to Prop)))) (P2: A0
+\to (A1 \to (A2 \to (A3 \to Prop)))) (P3: A0 \to (A1 \to (A2 \to (A3 \to
+Prop)))): Prop \def
+| ex4_4_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).(\forall
+(x3: A3).((P0 x0 x1 x2 x3) \to ((P1 x0 x1 x2 x3) \to ((P2 x0 x1 x2 x3) \to
+((P3 x0 x1 x2 x3) \to (ex4_4 A0 A1 A2 A3 P0 P1 P2 P3)))))))).
+
+inductive ex4_5 (A0: Set) (A1: Set) (A2: Set) (A3: Set) (A4: Set) (P0: A0 \to
+(A1 \to (A2 \to (A3 \to (A4 \to Prop))))) (P1: A0 \to (A1 \to (A2 \to (A3 \to
+(A4 \to Prop))))) (P2: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to Prop))))) (P3:
+A0 \to (A1 \to (A2 \to (A3 \to (A4 \to Prop))))): Prop \def
+| ex4_5_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).(\forall
+(x3: A3).(\forall (x4: A4).((P0 x0 x1 x2 x3 x4) \to ((P1 x0 x1 x2 x3 x4) \to
+((P2 x0 x1 x2 x3 x4) \to ((P3 x0 x1 x2 x3 x4) \to (ex4_5 A0 A1 A2 A3 A4 P0 P1
+P2 P3))))))))).
+
+inductive ex5_5 (A0: Set) (A1: Set) (A2: Set) (A3: Set) (A4: Set) (P0: A0 \to
+(A1 \to (A2 \to (A3 \to (A4 \to Prop))))) (P1: A0 \to (A1 \to (A2 \to (A3 \to
+(A4 \to Prop))))) (P2: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to Prop))))) (P3:
+A0 \to (A1 \to (A2 \to (A3 \to (A4 \to Prop))))) (P4: A0 \to (A1 \to (A2 \to
+(A3 \to (A4 \to Prop))))): Prop \def
+| ex5_5_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).(\forall
+(x3: A3).(\forall (x4: A4).((P0 x0 x1 x2 x3 x4) \to ((P1 x0 x1 x2 x3 x4) \to
+((P2 x0 x1 x2 x3 x4) \to ((P3 x0 x1 x2 x3 x4) \to ((P4 x0 x1 x2 x3 x4) \to
+(ex5_5 A0 A1 A2 A3 A4 P0 P1 P2 P3 P4)))))))))).
+
+inductive ex6_6 (A0: Set) (A1: Set) (A2: Set) (A3: Set) (A4: Set) (A5: Set)
+(P0: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to Prop)))))) (P1: A0 \to
+(A1 \to (A2 \to (A3 \to (A4 \to (A5 \to Prop)))))) (P2: A0 \to (A1 \to (A2
+\to (A3 \to (A4 \to (A5 \to Prop)))))) (P3: A0 \to (A1 \to (A2 \to (A3 \to
+(A4 \to (A5 \to Prop)))))) (P4: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5
+\to Prop)))))) (P5: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to
+Prop)))))): Prop \def
+| ex6_6_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).(\forall
+(x3: A3).(\forall (x4: A4).(\forall (x5: A5).((P0 x0 x1 x2 x3 x4 x5) \to ((P1
+x0 x1 x2 x3 x4 x5) \to ((P2 x0 x1 x2 x3 x4 x5) \to ((P3 x0 x1 x2 x3 x4 x5)
+\to ((P4 x0 x1 x2 x3 x4 x5) \to ((P5 x0 x1 x2 x3 x4 x5) \to (ex6_6 A0 A1 A2
+A3 A4 A5 P0 P1 P2 P3 P4 P5)))))))))))).
+
+inductive ex6_7 (A0: Set) (A1: Set) (A2: Set) (A3: Set) (A4: Set) (A5: Set)
+(A6: Set) (P0: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to (A6 \to
+Prop))))))) (P1: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to (A6 \to
+Prop))))))) (P2: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to (A6 \to
+Prop))))))) (P3: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to (A6 \to
+Prop))))))) (P4: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to (A6 \to
+Prop))))))) (P5: A0 \to (A1 \to (A2 \to (A3 \to (A4 \to (A5 \to (A6 \to
+Prop))))))): Prop \def
+| ex6_7_intro: \forall (x0: A0).(\forall (x1: A1).(\forall (x2: A2).(\forall
+(x3: A3).(\forall (x4: A4).(\forall (x5: A5).(\forall (x6: A6).((P0 x0 x1 x2
+x3 x4 x5 x6) \to ((P1 x0 x1 x2 x3 x4 x5 x6) \to ((P2 x0 x1 x2 x3 x4 x5 x6)
+\to ((P3 x0 x1 x2 x3 x4 x5 x6) \to ((P4 x0 x1 x2 x3 x4 x5 x6) \to ((P5 x0 x1
+x2 x3 x4 x5 x6) \to (ex6_7 A0 A1 A2 A3 A4 A5 A6 P0 P1 P2 P3 P4
+P5))))))))))))).
+