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4 (* ||A|| A project by Andrea Asperti *)
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7 (* ||T|| The HELM team. *)
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15 (* This file was automatically generated: do not edit *********************)
17 set "baseuri" "cic:/matita/LAMBDA-TYPES/Base-1/ext/arith".
19 include "preamble.ma".
22 \forall (n1: nat).(\forall (n2: nat).(or (eq nat n1 n2) ((eq nat n1 n2) \to
23 (\forall (P: Prop).P))))
25 \lambda (n1: nat).(nat_ind (\lambda (n: nat).(\forall (n2: nat).(or (eq nat
26 n n2) ((eq nat n n2) \to (\forall (P: Prop).P))))) (\lambda (n2:
27 nat).(nat_ind (\lambda (n: nat).(or (eq nat O n) ((eq nat O n) \to (\forall
28 (P: Prop).P)))) (or_introl (eq nat O O) ((eq nat O O) \to (\forall (P:
29 Prop).P)) (refl_equal nat O)) (\lambda (n: nat).(\lambda (_: (or (eq nat O n)
30 ((eq nat O n) \to (\forall (P: Prop).P)))).(or_intror (eq nat O (S n)) ((eq
31 nat O (S n)) \to (\forall (P: Prop).P)) (\lambda (H0: (eq nat O (S
32 n))).(\lambda (P: Prop).(let H1 \def (eq_ind nat O (\lambda (ee: nat).(match
33 ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow True | (S _)
34 \Rightarrow False])) I (S n) H0) in (False_ind P H1))))))) n2)) (\lambda (n:
35 nat).(\lambda (H: ((\forall (n2: nat).(or (eq nat n n2) ((eq nat n n2) \to
36 (\forall (P: Prop).P)))))).(\lambda (n2: nat).(nat_ind (\lambda (n0: nat).(or
37 (eq nat (S n) n0) ((eq nat (S n) n0) \to (\forall (P: Prop).P)))) (or_intror
38 (eq nat (S n) O) ((eq nat (S n) O) \to (\forall (P: Prop).P)) (\lambda (H0:
39 (eq nat (S n) O)).(\lambda (P: Prop).(let H1 \def (eq_ind nat (S n) (\lambda
40 (ee: nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow
41 False | (S _) \Rightarrow True])) I O H0) in (False_ind P H1))))) (\lambda
42 (n0: nat).(\lambda (H0: (or (eq nat (S n) n0) ((eq nat (S n) n0) \to (\forall
43 (P: Prop).P)))).(or_ind (eq nat n n0) ((eq nat n n0) \to (\forall (P:
44 Prop).P)) (or (eq nat (S n) (S n0)) ((eq nat (S n) (S n0)) \to (\forall (P:
45 Prop).P))) (\lambda (H1: (eq nat n n0)).(let H2 \def (eq_ind_r nat n0
46 (\lambda (n3: nat).(or (eq nat (S n) n3) ((eq nat (S n) n3) \to (\forall (P:
47 Prop).P)))) H0 n H1) in (eq_ind nat n (\lambda (n3: nat).(or (eq nat (S n) (S
48 n3)) ((eq nat (S n) (S n3)) \to (\forall (P: Prop).P)))) (or_introl (eq nat
49 (S n) (S n)) ((eq nat (S n) (S n)) \to (\forall (P: Prop).P)) (refl_equal nat
50 (S n))) n0 H1))) (\lambda (H1: (((eq nat n n0) \to (\forall (P:
51 Prop).P)))).(or_intror (eq nat (S n) (S n0)) ((eq nat (S n) (S n0)) \to
52 (\forall (P: Prop).P)) (\lambda (H2: (eq nat (S n) (S n0))).(\lambda (P:
53 Prop).(let H3 \def (f_equal nat nat (\lambda (e: nat).(match e in nat return
54 (\lambda (_: nat).nat) with [O \Rightarrow n | (S n3) \Rightarrow n3])) (S n)
55 (S n0) H2) in (let H4 \def (eq_ind_r nat n0 (\lambda (n3: nat).((eq nat n n3)
56 \to (\forall (P0: Prop).P0))) H1 n H3) in (let H5 \def (eq_ind_r nat n0
57 (\lambda (n3: nat).(or (eq nat (S n) n3) ((eq nat (S n) n3) \to (\forall (P0:
58 Prop).P0)))) H0 n H3) in (H4 (refl_equal nat n) P)))))))) (H n0)))) n2))))
62 \forall (n: nat).(\forall (m: nat).(\forall (p: nat).((eq nat (plus m n)
63 (plus p n)) \to (eq nat m p))))
65 \lambda (n: nat).(\lambda (m: nat).(\lambda (p: nat).(\lambda (H: (eq nat
66 (plus m n) (plus p n))).(plus_reg_l n m p (eq_ind_r nat (plus m n) (\lambda
67 (n0: nat).(eq nat n0 (plus n p))) (eq_ind_r nat (plus p n) (\lambda (n0:
68 nat).(eq nat n0 (plus n p))) (sym_eq nat (plus n p) (plus p n) (plus_comm n
69 p)) (plus m n) H) (plus n m) (plus_comm n m)))))).
72 \forall (m: nat).(\forall (n: nat).(eq nat (minus (plus m n) n) m))
74 \lambda (m: nat).(\lambda (n: nat).(eq_ind_r nat (plus n m) (\lambda (n0:
75 nat).(eq nat (minus n0 n) m)) (minus_plus n m) (plus m n) (plus_comm m n))).
77 theorem plus_permute_2_in_3:
78 \forall (x: nat).(\forall (y: nat).(\forall (z: nat).(eq nat (plus (plus x
79 y) z) (plus (plus x z) y))))
81 \lambda (x: nat).(\lambda (y: nat).(\lambda (z: nat).(eq_ind_r nat (plus x
82 (plus y z)) (\lambda (n: nat).(eq nat n (plus (plus x z) y))) (eq_ind_r nat
83 (plus z y) (\lambda (n: nat).(eq nat (plus x n) (plus (plus x z) y))) (eq_ind
84 nat (plus (plus x z) y) (\lambda (n: nat).(eq nat n (plus (plus x z) y)))
85 (refl_equal nat (plus (plus x z) y)) (plus x (plus z y)) (plus_assoc_reverse
86 x z y)) (plus y z) (plus_comm y z)) (plus (plus x y) z) (plus_assoc_reverse x
89 theorem plus_permute_2_in_3_assoc:
90 \forall (n: nat).(\forall (h: nat).(\forall (k: nat).(eq nat (plus (plus n
91 h) k) (plus n (plus k h)))))
93 \lambda (n: nat).(\lambda (h: nat).(\lambda (k: nat).(eq_ind_r nat (plus
94 (plus n k) h) (\lambda (n0: nat).(eq nat n0 (plus n (plus k h)))) (eq_ind_r
95 nat (plus (plus n k) h) (\lambda (n0: nat).(eq nat (plus (plus n k) h) n0))
96 (refl_equal nat (plus (plus n k) h)) (plus n (plus k h)) (plus_assoc n k h))
97 (plus (plus n h) k) (plus_permute_2_in_3 n h k)))).
100 \forall (x: nat).(\forall (y: nat).((eq nat (plus x y) O) \to (land (eq nat
103 \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((eq nat (plus
104 n y) O) \to (land (eq nat n O) (eq nat y O))))) (\lambda (y: nat).(\lambda
105 (H: (eq nat (plus O y) O)).(conj (eq nat O O) (eq nat y O) (refl_equal nat O)
106 H))) (\lambda (n: nat).(\lambda (_: ((\forall (y: nat).((eq nat (plus n y) O)
107 \to (land (eq nat n O) (eq nat y O)))))).(\lambda (y: nat).(\lambda (H0: (eq
108 nat (plus (S n) y) O)).(let H1 \def (match H0 in eq return (\lambda (n0:
109 nat).(\lambda (_: (eq ? ? n0)).((eq nat n0 O) \to (land (eq nat (S n) O) (eq
110 nat y O))))) with [refl_equal \Rightarrow (\lambda (H1: (eq nat (plus (S n)
111 y) O)).(let H2 \def (eq_ind nat (plus (S n) y) (\lambda (e: nat).(match e in
112 nat return (\lambda (_: nat).Prop) with [O \Rightarrow False | (S _)
113 \Rightarrow True])) I O H1) in (False_ind (land (eq nat (S n) O) (eq nat y
114 O)) H2)))]) in (H1 (refl_equal nat O))))))) x).
117 \forall (x: nat).(eq nat (minus (S x) (S O)) x)
119 \lambda (x: nat).(eq_ind nat x (\lambda (n: nat).(eq nat n x)) (refl_equal
120 nat x) (minus x O) (minus_n_O x)).
123 \forall (i: nat).(\forall (j: nat).(or (not (eq nat i j)) (eq nat i j)))
125 \lambda (i: nat).(nat_ind (\lambda (n: nat).(\forall (j: nat).(or (not (eq
126 nat n j)) (eq nat n j)))) (\lambda (j: nat).(nat_ind (\lambda (n: nat).(or
127 (not (eq nat O n)) (eq nat O n))) (or_intror (not (eq nat O O)) (eq nat O O)
128 (refl_equal nat O)) (\lambda (n: nat).(\lambda (_: (or (not (eq nat O n)) (eq
129 nat O n))).(or_introl (not (eq nat O (S n))) (eq nat O (S n)) (O_S n)))) j))
130 (\lambda (n: nat).(\lambda (H: ((\forall (j: nat).(or (not (eq nat n j)) (eq
131 nat n j))))).(\lambda (j: nat).(nat_ind (\lambda (n0: nat).(or (not (eq nat
132 (S n) n0)) (eq nat (S n) n0))) (or_introl (not (eq nat (S n) O)) (eq nat (S
133 n) O) (sym_not_eq nat O (S n) (O_S n))) (\lambda (n0: nat).(\lambda (_: (or
134 (not (eq nat (S n) n0)) (eq nat (S n) n0))).(or_ind (not (eq nat n n0)) (eq
135 nat n n0) (or (not (eq nat (S n) (S n0))) (eq nat (S n) (S n0))) (\lambda
136 (H1: (not (eq nat n n0))).(or_introl (not (eq nat (S n) (S n0))) (eq nat (S
137 n) (S n0)) (not_eq_S n n0 H1))) (\lambda (H1: (eq nat n n0)).(or_intror (not
138 (eq nat (S n) (S n0))) (eq nat (S n) (S n0)) (f_equal nat nat S n n0 H1))) (H
142 \forall (i: nat).(\forall (j: nat).(\forall (P: Prop).((((not (eq nat i j))
143 \to P)) \to ((((eq nat i j) \to P)) \to P))))
145 \lambda (i: nat).(\lambda (j: nat).(\lambda (P: Prop).(\lambda (H: (((not
146 (eq nat i j)) \to P))).(\lambda (H0: (((eq nat i j) \to P))).(let o \def
147 (eq_nat_dec i j) in (or_ind (not (eq nat i j)) (eq nat i j) P H H0 o)))))).
150 \forall (m: nat).(\forall (n: nat).(\forall (P: Prop).((le m n) \to ((le (S
153 \lambda (m: nat).(nat_ind (\lambda (n: nat).(\forall (n0: nat).(\forall (P:
154 Prop).((le n n0) \to ((le (S n0) n) \to P))))) (\lambda (n: nat).(\lambda (P:
155 Prop).(\lambda (_: (le O n)).(\lambda (H0: (le (S n) O)).(let H1 \def (match
156 H0 in le return (\lambda (n0: nat).(\lambda (_: (le ? n0)).((eq nat n0 O) \to
157 P))) with [le_n \Rightarrow (\lambda (H1: (eq nat (S n) O)).(let H2 \def
158 (eq_ind nat (S n) (\lambda (e: nat).(match e in nat return (\lambda (_:
159 nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow True])) I O H1) in
160 (False_ind P H2))) | (le_S m0 H1) \Rightarrow (\lambda (H2: (eq nat (S m0)
161 O)).((let H3 \def (eq_ind nat (S m0) (\lambda (e: nat).(match e in nat return
162 (\lambda (_: nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow True]))
163 I O H2) in (False_ind ((le (S n) m0) \to P) H3)) H1))]) in (H1 (refl_equal
164 nat O))))))) (\lambda (n: nat).(\lambda (H: ((\forall (n0: nat).(\forall (P:
165 Prop).((le n n0) \to ((le (S n0) n) \to P)))))).(\lambda (n0: nat).(nat_ind
166 (\lambda (n1: nat).(\forall (P: Prop).((le (S n) n1) \to ((le (S n1) (S n))
167 \to P)))) (\lambda (P: Prop).(\lambda (H0: (le (S n) O)).(\lambda (_: (le (S
168 O) (S n))).(let H2 \def (match H0 in le return (\lambda (n1: nat).(\lambda
169 (_: (le ? n1)).((eq nat n1 O) \to P))) with [le_n \Rightarrow (\lambda (H2:
170 (eq nat (S n) O)).(let H3 \def (eq_ind nat (S n) (\lambda (e: nat).(match e
171 in nat return (\lambda (_: nat).Prop) with [O \Rightarrow False | (S _)
172 \Rightarrow True])) I O H2) in (False_ind P H3))) | (le_S m0 H2) \Rightarrow
173 (\lambda (H3: (eq nat (S m0) O)).((let H4 \def (eq_ind nat (S m0) (\lambda
174 (e: nat).(match e in nat return (\lambda (_: nat).Prop) with [O \Rightarrow
175 False | (S _) \Rightarrow True])) I O H3) in (False_ind ((le (S n) m0) \to P)
176 H4)) H2))]) in (H2 (refl_equal nat O)))))) (\lambda (n1: nat).(\lambda (_:
177 ((\forall (P: Prop).((le (S n) n1) \to ((le (S n1) (S n)) \to P))))).(\lambda
178 (P: Prop).(\lambda (H1: (le (S n) (S n1))).(\lambda (H2: (le (S (S n1)) (S
179 n))).(H n1 P (le_S_n n n1 H1) (le_S_n (S n1) n H2))))))) n0)))) m).
182 \forall (x: nat).((le (S x) x) \to (\forall (P: Prop).P))
184 \lambda (x: nat).(\lambda (H: (le (S x) x)).(\lambda (P: Prop).(let H0 \def
185 le_Sn_n in (False_ind P (H0 x H))))).
188 \forall (x: nat).(\forall (y: nat).(le (minus x y) x))
190 \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).(le (minus n
191 y) n))) (\lambda (_: nat).(le_n O)) (\lambda (n: nat).(\lambda (H: ((\forall
192 (y: nat).(le (minus n y) n)))).(\lambda (y: nat).(nat_ind (\lambda (n0:
193 nat).(le (minus (S n) n0) (S n))) (le_n (S n)) (\lambda (n0: nat).(\lambda
194 (_: (le (match n0 with [O \Rightarrow (S n) | (S l) \Rightarrow (minus n l)])
195 (S n))).(le_S (minus n n0) n (H n0)))) y)))) x).
197 theorem le_plus_minus_sym:
198 \forall (n: nat).(\forall (m: nat).((le n m) \to (eq nat m (plus (minus m n)
201 \lambda (n: nat).(\lambda (m: nat).(\lambda (H: (le n m)).(eq_ind_r nat
202 (plus n (minus m n)) (\lambda (n0: nat).(eq nat m n0)) (le_plus_minus n m H)
203 (plus (minus m n) n) (plus_comm (minus m n) n)))).
205 theorem le_minus_minus:
206 \forall (x: nat).(\forall (y: nat).((le x y) \to (\forall (z: nat).((le y z)
207 \to (le (minus y x) (minus z x))))))
209 \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (le x y)).(\lambda (z:
210 nat).(\lambda (H0: (le y z)).(plus_le_reg_l x (minus y x) (minus z x)
211 (eq_ind_r nat y (\lambda (n: nat).(le n (plus x (minus z x)))) (eq_ind_r nat
212 z (\lambda (n: nat).(le y n)) H0 (plus x (minus z x)) (le_plus_minus_r x z
213 (le_trans x y z H H0))) (plus x (minus y x)) (le_plus_minus_r x y H))))))).
215 theorem le_minus_plus:
216 \forall (z: nat).(\forall (x: nat).((le z x) \to (\forall (y: nat).(eq nat
217 (minus (plus x y) z) (plus (minus x z) y)))))
219 \lambda (z: nat).(nat_ind (\lambda (n: nat).(\forall (x: nat).((le n x) \to
220 (\forall (y: nat).(eq nat (minus (plus x y) n) (plus (minus x n) y))))))
221 (\lambda (x: nat).(\lambda (H: (le O x)).(let H0 \def (match H in le return
222 (\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n x) \to (\forall (y:
223 nat).(eq nat (minus (plus x y) O) (plus (minus x O) y)))))) with [le_n
224 \Rightarrow (\lambda (H0: (eq nat O x)).(eq_ind nat O (\lambda (n:
225 nat).(\forall (y: nat).(eq nat (minus (plus n y) O) (plus (minus n O) y))))
226 (\lambda (y: nat).(sym_eq nat (plus (minus O O) y) (minus (plus O y) O)
227 (minus_n_O (plus O y)))) x H0)) | (le_S m H0) \Rightarrow (\lambda (H1: (eq
228 nat (S m) x)).(eq_ind nat (S m) (\lambda (n: nat).((le O m) \to (\forall (y:
229 nat).(eq nat (minus (plus n y) O) (plus (minus n O) y))))) (\lambda (_: (le O
230 m)).(\lambda (y: nat).(refl_equal nat (plus (minus (S m) O) y)))) x H1 H0))])
231 in (H0 (refl_equal nat x))))) (\lambda (z0: nat).(\lambda (H: ((\forall (x:
232 nat).((le z0 x) \to (\forall (y: nat).(eq nat (minus (plus x y) z0) (plus
233 (minus x z0) y))))))).(\lambda (x: nat).(nat_ind (\lambda (n: nat).((le (S
234 z0) n) \to (\forall (y: nat).(eq nat (minus (plus n y) (S z0)) (plus (minus n
235 (S z0)) y))))) (\lambda (H0: (le (S z0) O)).(\lambda (y: nat).(let H1 \def
236 (match H0 in le return (\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n O)
237 \to (eq nat (minus (plus O y) (S z0)) (plus (minus O (S z0)) y))))) with
238 [le_n \Rightarrow (\lambda (H1: (eq nat (S z0) O)).(let H2 \def (eq_ind nat
239 (S z0) (\lambda (e: nat).(match e in nat return (\lambda (_: nat).Prop) with
240 [O \Rightarrow False | (S _) \Rightarrow True])) I O H1) in (False_ind (eq
241 nat (minus (plus O y) (S z0)) (plus (minus O (S z0)) y)) H2))) | (le_S m H1)
242 \Rightarrow (\lambda (H2: (eq nat (S m) O)).((let H3 \def (eq_ind nat (S m)
243 (\lambda (e: nat).(match e in nat return (\lambda (_: nat).Prop) with [O
244 \Rightarrow False | (S _) \Rightarrow True])) I O H2) in (False_ind ((le (S
245 z0) m) \to (eq nat (minus (plus O y) (S z0)) (plus (minus O (S z0)) y))) H3))
246 H1))]) in (H1 (refl_equal nat O))))) (\lambda (n: nat).(\lambda (_: (((le (S
247 z0) n) \to (\forall (y: nat).(eq nat (minus (plus n y) (S z0)) (plus (minus n
248 (S z0)) y)))))).(\lambda (H1: (le (S z0) (S n))).(\lambda (y: nat).(H n
249 (le_S_n z0 n H1) y))))) x)))) z).
252 \forall (x: nat).(\forall (z: nat).(\forall (y: nat).((le (plus x y) z) \to
253 (le x (minus z y)))))
255 \lambda (x: nat).(\lambda (z: nat).(\lambda (y: nat).(\lambda (H: (le (plus
256 x y) z)).(eq_ind nat (minus (plus x y) y) (\lambda (n: nat).(le n (minus z
257 y))) (le_minus_minus y (plus x y) (le_plus_r x y) z H) x (minus_plus_r x
260 theorem le_trans_plus_r:
261 \forall (x: nat).(\forall (y: nat).(\forall (z: nat).((le (plus x y) z) \to
264 \lambda (x: nat).(\lambda (y: nat).(\lambda (z: nat).(\lambda (H: (le (plus
265 x y) z)).(le_trans y (plus x y) z (le_plus_r x y) H)))).
268 \forall (m: nat).(\forall (x: nat).((le (S m) x) \to (ex2 nat (\lambda (n:
269 nat).(eq nat x (S n))) (\lambda (n: nat).(le m n)))))
271 \lambda (m: nat).(\lambda (x: nat).(\lambda (H: (le (S m) x)).(let H0 \def
272 (match H in le return (\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n x)
273 \to (ex2 nat (\lambda (n0: nat).(eq nat x (S n0))) (\lambda (n0: nat).(le m
274 n0)))))) with [le_n \Rightarrow (\lambda (H0: (eq nat (S m) x)).(eq_ind nat
275 (S m) (\lambda (n: nat).(ex2 nat (\lambda (n0: nat).(eq nat n (S n0)))
276 (\lambda (n0: nat).(le m n0)))) (ex_intro2 nat (\lambda (n: nat).(eq nat (S
277 m) (S n))) (\lambda (n: nat).(le m n)) m (refl_equal nat (S m)) (le_n m)) x
278 H0)) | (le_S m0 H0) \Rightarrow (\lambda (H1: (eq nat (S m0) x)).(eq_ind nat
279 (S m0) (\lambda (n: nat).((le (S m) m0) \to (ex2 nat (\lambda (n0: nat).(eq
280 nat n (S n0))) (\lambda (n0: nat).(le m n0))))) (\lambda (H2: (le (S m)
281 m0)).(ex_intro2 nat (\lambda (n: nat).(eq nat (S m0) (S n))) (\lambda (n:
282 nat).(le m n)) m0 (refl_equal nat (S m0)) (le_S_n m m0 (le_S (S m) m0 H2))))
283 x H1 H0))]) in (H0 (refl_equal nat x))))).
285 theorem lt_x_plus_x_Sy:
286 \forall (x: nat).(\forall (y: nat).(lt x (plus x (S y))))
288 \lambda (x: nat).(\lambda (y: nat).(eq_ind_r nat (plus (S y) x) (\lambda (n:
289 nat).(lt x n)) (le_S_n (S x) (S (plus y x)) (le_n_S (S x) (S (plus y x))
290 (le_n_S x (plus y x) (le_plus_r y x)))) (plus x (S y)) (plus_comm x (S y)))).
292 theorem simpl_lt_plus_r:
293 \forall (p: nat).(\forall (n: nat).(\forall (m: nat).((lt (plus n p) (plus m
296 \lambda (p: nat).(\lambda (n: nat).(\lambda (m: nat).(\lambda (H: (lt (plus
297 n p) (plus m p))).(plus_lt_reg_l n m p (let H0 \def (eq_ind nat (plus n p)
298 (\lambda (n0: nat).(lt n0 (plus m p))) H (plus p n) (plus_comm n p)) in (let
299 H1 \def (eq_ind nat (plus m p) (\lambda (n0: nat).(lt (plus p n) n0)) H0
300 (plus p m) (plus_comm m p)) in H1)))))).
303 \forall (x: nat).(\forall (y: nat).((lt y x) \to (eq nat (minus x y) (S
306 \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((lt y n) \to
307 (eq nat (minus n y) (S (minus n (S y))))))) (\lambda (y: nat).(\lambda (H:
308 (lt y O)).(let H0 \def (match H in le return (\lambda (n: nat).(\lambda (_:
309 (le ? n)).((eq nat n O) \to (eq nat (minus O y) (S (minus O (S y))))))) with
310 [le_n \Rightarrow (\lambda (H0: (eq nat (S y) O)).(let H1 \def (eq_ind nat (S
311 y) (\lambda (e: nat).(match e in nat return (\lambda (_: nat).Prop) with [O
312 \Rightarrow False | (S _) \Rightarrow True])) I O H0) in (False_ind (eq nat
313 (minus O y) (S (minus O (S y)))) H1))) | (le_S m H0) \Rightarrow (\lambda
314 (H1: (eq nat (S m) O)).((let H2 \def (eq_ind nat (S m) (\lambda (e:
315 nat).(match e in nat return (\lambda (_: nat).Prop) with [O \Rightarrow False
316 | (S _) \Rightarrow True])) I O H1) in (False_ind ((le (S y) m) \to (eq nat
317 (minus O y) (S (minus O (S y))))) H2)) H0))]) in (H0 (refl_equal nat O)))))
318 (\lambda (n: nat).(\lambda (H: ((\forall (y: nat).((lt y n) \to (eq nat
319 (minus n y) (S (minus n (S y)))))))).(\lambda (y: nat).(nat_ind (\lambda (n0:
320 nat).((lt n0 (S n)) \to (eq nat (minus (S n) n0) (S (minus (S n) (S n0))))))
321 (\lambda (_: (lt O (S n))).(eq_ind nat n (\lambda (n0: nat).(eq nat (S n) (S
322 n0))) (refl_equal nat (S n)) (minus n O) (minus_n_O n))) (\lambda (n0:
323 nat).(\lambda (_: (((lt n0 (S n)) \to (eq nat (minus (S n) n0) (S (minus (S
324 n) (S n0))))))).(\lambda (H1: (lt (S n0) (S n))).(let H2 \def (le_S_n (S n0)
325 n H1) in (H n0 H2))))) y)))) x).
327 theorem lt_plus_minus:
328 \forall (x: nat).(\forall (y: nat).((lt x y) \to (eq nat y (S (plus x (minus
331 \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(le_plus_minus (S
334 theorem lt_plus_minus_r:
335 \forall (x: nat).(\forall (y: nat).((lt x y) \to (eq nat y (S (plus (minus y
338 \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(eq_ind_r nat
339 (plus x (minus y (S x))) (\lambda (n: nat).(eq nat y (S n))) (lt_plus_minus x
340 y H) (plus (minus y (S x)) x) (plus_comm (minus y (S x)) x)))).
343 \forall (x: nat).((lt O x) \to (eq nat x (S (minus x (S O)))))
345 \lambda (x: nat).(\lambda (H: (lt O x)).(eq_ind nat (minus x O) (\lambda (n:
346 nat).(eq nat x n)) (eq_ind nat x (\lambda (n: nat).(eq nat x n)) (refl_equal
347 nat x) (minus x O) (minus_n_O x)) (S (minus x (S O))) (minus_x_Sy x O H))).
350 \forall (y: nat).(\forall (x: nat).((lt x y) \to (le x (pred y))))
352 \lambda (y: nat).(nat_ind (\lambda (n: nat).(\forall (x: nat).((lt x n) \to
353 (le x (pred n))))) (\lambda (x: nat).(\lambda (H: (lt x O)).(let H0 \def
354 (match H in le return (\lambda (n: nat).(\lambda (_: (le ? n)).((eq nat n O)
355 \to (le x O)))) with [le_n \Rightarrow (\lambda (H0: (eq nat (S x) O)).(let
356 H1 \def (eq_ind nat (S x) (\lambda (e: nat).(match e in nat return (\lambda
357 (_: nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow True])) I O H0)
358 in (False_ind (le x O) H1))) | (le_S m H0) \Rightarrow (\lambda (H1: (eq nat
359 (S m) O)).((let H2 \def (eq_ind nat (S m) (\lambda (e: nat).(match e in nat
360 return (\lambda (_: nat).Prop) with [O \Rightarrow False | (S _) \Rightarrow
361 True])) I O H1) in (False_ind ((le (S x) m) \to (le x O)) H2)) H0))]) in (H0
362 (refl_equal nat O))))) (\lambda (n: nat).(\lambda (_: ((\forall (x: nat).((lt
363 x n) \to (le x (pred n)))))).(\lambda (x: nat).(\lambda (H0: (lt x (S
364 n))).(le_S_n x n H0))))) y).
367 \forall (x: nat).(\forall (y: nat).((lt x y) \to (le x (minus y (S O)))))
369 \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(le_minus x y (S
370 O) (eq_ind_r nat (plus (S O) x) (\lambda (n: nat).(le n y)) H (plus x (S O))
371 (plus_comm x (S O)))))).
374 \forall (n: nat).(\forall (d: nat).(\forall (P: Prop).((((lt n d) \to P))
375 \to ((((le d n) \to P)) \to P))))
377 \lambda (n: nat).(\lambda (d: nat).(\lambda (P: Prop).(\lambda (H: (((lt n
378 d) \to P))).(\lambda (H0: (((le d n) \to P))).(let H1 \def (le_or_lt d n) in
379 (or_ind (le d n) (lt n d) P H0 H H1)))))).
382 \forall (x: nat).(\forall (y: nat).(\forall (P: Prop).((((lt x y) \to P))
383 \to ((((eq nat x y) \to P)) \to ((le x y) \to P)))))
385 \lambda (x: nat).(\lambda (y: nat).(\lambda (P: Prop).(\lambda (H: (((lt x
386 y) \to P))).(\lambda (H0: (((eq nat x y) \to P))).(\lambda (H1: (le x
387 y)).(or_ind (lt x y) (eq nat x y) P H H0 (le_lt_or_eq x y H1))))))).
390 \forall (x: nat).(\forall (y: nat).(\forall (P: Prop).((((lt x y) \to P))
391 \to ((((eq nat x y) \to P)) \to ((((lt y x) \to P)) \to P)))))
393 \lambda (x: nat).(\lambda (y: nat).(\lambda (P: Prop).(\lambda (H: (((lt x
394 y) \to P))).(\lambda (H0: (((eq nat x y) \to P))).(\lambda (H1: (((lt y x)
395 \to P))).(lt_le_e x y P H (\lambda (H2: (le y x)).(lt_eq_e y x P H1 (\lambda
396 (H3: (eq nat y x)).(H0 (sym_eq nat y x H3))) H2)))))))).
399 \forall (x: nat).(\forall (n: nat).((lt x (S n)) \to (or (eq nat x O) (ex2
400 nat (\lambda (m: nat).(eq nat x (S m))) (\lambda (m: nat).(lt m n))))))
402 \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (n0: nat).((lt n (S
403 n0)) \to (or (eq nat n O) (ex2 nat (\lambda (m: nat).(eq nat n (S m)))
404 (\lambda (m: nat).(lt m n0))))))) (\lambda (n: nat).(\lambda (_: (lt O (S
405 n))).(or_introl (eq nat O O) (ex2 nat (\lambda (m: nat).(eq nat O (S m)))
406 (\lambda (m: nat).(lt m n))) (refl_equal nat O)))) (\lambda (n: nat).(\lambda
407 (_: ((\forall (n0: nat).((lt n (S n0)) \to (or (eq nat n O) (ex2 nat (\lambda
408 (m: nat).(eq nat n (S m))) (\lambda (m: nat).(lt m n0)))))))).(\lambda (n0:
409 nat).(\lambda (H0: (lt (S n) (S n0))).(or_intror (eq nat (S n) O) (ex2 nat
410 (\lambda (m: nat).(eq nat (S n) (S m))) (\lambda (m: nat).(lt m n0)))
411 (ex_intro2 nat (\lambda (m: nat).(eq nat (S n) (S m))) (\lambda (m: nat).(lt
412 m n0)) n (refl_equal nat (S n)) (le_S_n (S n) n0 H0))))))) x).
415 \forall (x: nat).(\forall (y: nat).((le x y) \to ((lt y x) \to (\forall (P:
418 \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (le x y)).(\lambda (H0: (lt
419 y x)).(\lambda (P: Prop).(False_ind P (le_not_lt x y H H0)))))).
422 \forall (x: nat).(\forall (y: nat).((lt x y) \to (not (eq nat x y))))
424 \lambda (x: nat).(\lambda (y: nat).(\lambda (H: (lt x y)).(\lambda (H0: (eq
425 nat x y)).(let H1 \def (eq_ind nat x (\lambda (n: nat).(lt n y)) H y H0) in
426 (lt_irrefl y H1))))).
429 \forall (h2: nat).(\forall (d2: nat).(\forall (n: nat).((le (plus d2 h2) n)
430 \to (\forall (h1: nat).(le (plus d2 h1) (minus (plus n h1) h2))))))
432 \lambda (h2: nat).(\lambda (d2: nat).(\lambda (n: nat).(\lambda (H: (le
433 (plus d2 h2) n)).(\lambda (h1: nat).(eq_ind nat (minus (plus h2 (plus d2 h1))
434 h2) (\lambda (n0: nat).(le n0 (minus (plus n h1) h2))) (le_minus_minus h2
435 (plus h2 (plus d2 h1)) (le_plus_l h2 (plus d2 h1)) (plus n h1) (eq_ind_r nat
436 (plus (plus h2 d2) h1) (\lambda (n0: nat).(le n0 (plus n h1))) (eq_ind_r nat
437 (plus d2 h2) (\lambda (n0: nat).(le (plus n0 h1) (plus n h1))) (le_S_n (plus
438 (plus d2 h2) h1) (plus n h1) (lt_le_S (plus (plus d2 h2) h1) (S (plus n h1))
439 (le_lt_n_Sm (plus (plus d2 h2) h1) (plus n h1) (plus_le_compat (plus d2 h2) n
440 h1 h1 H (le_n h1))))) (plus h2 d2) (plus_comm h2 d2)) (plus h2 (plus d2 h1))
441 (plus_assoc h2 d2 h1))) (plus d2 h1) (minus_plus h2 (plus d2 h1))))))).
444 \forall (x: nat).(\forall (y: nat).((le x y) \to (eq nat (minus x y) O)))
446 \lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((le n y) \to
447 (eq nat (minus n y) O)))) (\lambda (y: nat).(\lambda (_: (le O
448 y)).(refl_equal nat O))) (\lambda (x0: nat).(\lambda (H: ((\forall (y:
449 nat).((le x0 y) \to (eq nat (minus x0 y) O))))).(\lambda (y: nat).(nat_ind
450 (\lambda (n: nat).((le (S x0) n) \to (eq nat (match n with [O \Rightarrow (S
451 x0) | (S l) \Rightarrow (minus x0 l)]) O))) (\lambda (H0: (le (S x0)
452 O)).(ex2_ind nat (\lambda (n: nat).(eq nat O (S n))) (\lambda (n: nat).(le x0
453 n)) (eq nat (S x0) O) (\lambda (x1: nat).(\lambda (H1: (eq nat O (S
454 x1))).(\lambda (_: (le x0 x1)).(let H3 \def (eq_ind nat O (\lambda (ee:
455 nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow True
456 | (S _) \Rightarrow False])) I (S x1) H1) in (False_ind (eq nat (S x0) O)
457 H3))))) (le_gen_S x0 O H0))) (\lambda (n: nat).(\lambda (_: (((le (S x0) n)
458 \to (eq nat (match n with [O \Rightarrow (S x0) | (S l) \Rightarrow (minus x0
459 l)]) O)))).(\lambda (H1: (le (S x0) (S n))).(H n (le_S_n x0 n H1))))) y))))
463 \forall (z: nat).(\forall (x: nat).(\forall (y: nat).((le z x) \to ((le z y)
464 \to ((eq nat (minus x z) (minus y z)) \to (eq nat x y))))))
466 \lambda (z: nat).(nat_ind (\lambda (n: nat).(\forall (x: nat).(\forall (y:
467 nat).((le n x) \to ((le n y) \to ((eq nat (minus x n) (minus y n)) \to (eq
468 nat x y))))))) (\lambda (x: nat).(\lambda (y: nat).(\lambda (_: (le O
469 x)).(\lambda (_: (le O y)).(\lambda (H1: (eq nat (minus x O) (minus y
470 O))).(let H2 \def (eq_ind_r nat (minus x O) (\lambda (n: nat).(eq nat n
471 (minus y O))) H1 x (minus_n_O x)) in (let H3 \def (eq_ind_r nat (minus y O)
472 (\lambda (n: nat).(eq nat x n)) H2 y (minus_n_O y)) in H3))))))) (\lambda
473 (z0: nat).(\lambda (IH: ((\forall (x: nat).(\forall (y: nat).((le z0 x) \to
474 ((le z0 y) \to ((eq nat (minus x z0) (minus y z0)) \to (eq nat x
475 y)))))))).(\lambda (x: nat).(nat_ind (\lambda (n: nat).(\forall (y: nat).((le
476 (S z0) n) \to ((le (S z0) y) \to ((eq nat (minus n (S z0)) (minus y (S z0)))
477 \to (eq nat n y)))))) (\lambda (y: nat).(\lambda (H: (le (S z0) O)).(\lambda
478 (_: (le (S z0) y)).(\lambda (_: (eq nat (minus O (S z0)) (minus y (S
479 z0)))).(ex2_ind nat (\lambda (n: nat).(eq nat O (S n))) (\lambda (n: nat).(le
480 z0 n)) (eq nat O y) (\lambda (x0: nat).(\lambda (H2: (eq nat O (S
481 x0))).(\lambda (_: (le z0 x0)).(let H4 \def (eq_ind nat O (\lambda (ee:
482 nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow True
483 | (S _) \Rightarrow False])) I (S x0) H2) in (False_ind (eq nat O y) H4)))))
484 (le_gen_S z0 O H)))))) (\lambda (x0: nat).(\lambda (_: ((\forall (y:
485 nat).((le (S z0) x0) \to ((le (S z0) y) \to ((eq nat (minus x0 (S z0)) (minus
486 y (S z0))) \to (eq nat x0 y))))))).(\lambda (y: nat).(nat_ind (\lambda (n:
487 nat).((le (S z0) (S x0)) \to ((le (S z0) n) \to ((eq nat (minus (S x0) (S
488 z0)) (minus n (S z0))) \to (eq nat (S x0) n))))) (\lambda (_: (le (S z0) (S
489 x0))).(\lambda (H0: (le (S z0) O)).(\lambda (_: (eq nat (minus (S x0) (S z0))
490 (minus O (S z0)))).(ex2_ind nat (\lambda (n: nat).(eq nat O (S n))) (\lambda
491 (n: nat).(le z0 n)) (eq nat (S x0) O) (\lambda (x1: nat).(\lambda (H2: (eq
492 nat O (S x1))).(\lambda (_: (le z0 x1)).(let H4 \def (eq_ind nat O (\lambda
493 (ee: nat).(match ee in nat return (\lambda (_: nat).Prop) with [O \Rightarrow
494 True | (S _) \Rightarrow False])) I (S x1) H2) in (False_ind (eq nat (S x0)
495 O) H4))))) (le_gen_S z0 O H0))))) (\lambda (y0: nat).(\lambda (_: (((le (S
496 z0) (S x0)) \to ((le (S z0) y0) \to ((eq nat (minus (S x0) (S z0)) (minus y0
497 (S z0))) \to (eq nat (S x0) y0)))))).(\lambda (H: (le (S z0) (S
498 x0))).(\lambda (H0: (le (S z0) (S y0))).(\lambda (H1: (eq nat (minus (S x0)
499 (S z0)) (minus (S y0) (S z0)))).(f_equal nat nat S x0 y0 (IH x0 y0 (le_S_n z0
500 x0 H) (le_S_n z0 y0 H0) H1))))))) y)))) x)))) z).
503 \forall (z: nat).(\forall (x1: nat).(\forall (x2: nat).(\forall (y1:
504 nat).(\forall (y2: nat).((le x1 z) \to ((le x2 z) \to ((eq nat (plus (minus z
505 x1) y1) (plus (minus z x2) y2)) \to (eq nat (plus x1 y2) (plus x2 y1)))))))))
507 \lambda (z: nat).(nat_ind (\lambda (n: nat).(\forall (x1: nat).(\forall (x2:
508 nat).(\forall (y1: nat).(\forall (y2: nat).((le x1 n) \to ((le x2 n) \to ((eq
509 nat (plus (minus n x1) y1) (plus (minus n x2) y2)) \to (eq nat (plus x1 y2)
510 (plus x2 y1)))))))))) (\lambda (x1: nat).(\lambda (x2: nat).(\lambda (y1:
511 nat).(\lambda (y2: nat).(\lambda (H: (le x1 O)).(\lambda (H0: (le x2
512 O)).(\lambda (H1: (eq nat y1 y2)).(eq_ind nat y1 (\lambda (n: nat).(eq nat
513 (plus x1 n) (plus x2 y1))) (let H_y \def (le_n_O_eq x2 H0) in (eq_ind nat O
514 (\lambda (n: nat).(eq nat (plus x1 y1) (plus n y1))) (let H_y0 \def
515 (le_n_O_eq x1 H) in (eq_ind nat O (\lambda (n: nat).(eq nat (plus n y1) (plus
516 O y1))) (refl_equal nat (plus O y1)) x1 H_y0)) x2 H_y)) y2 H1))))))))
517 (\lambda (z0: nat).(\lambda (IH: ((\forall (x1: nat).(\forall (x2:
518 nat).(\forall (y1: nat).(\forall (y2: nat).((le x1 z0) \to ((le x2 z0) \to
519 ((eq nat (plus (minus z0 x1) y1) (plus (minus z0 x2) y2)) \to (eq nat (plus
520 x1 y2) (plus x2 y1))))))))))).(\lambda (x1: nat).(nat_ind (\lambda (n:
521 nat).(\forall (x2: nat).(\forall (y1: nat).(\forall (y2: nat).((le n (S z0))
522 \to ((le x2 (S z0)) \to ((eq nat (plus (minus (S z0) n) y1) (plus (minus (S
523 z0) x2) y2)) \to (eq nat (plus n y2) (plus x2 y1))))))))) (\lambda (x2:
524 nat).(nat_ind (\lambda (n: nat).(\forall (y1: nat).(\forall (y2: nat).((le O
525 (S z0)) \to ((le n (S z0)) \to ((eq nat (plus (minus (S z0) O) y1) (plus
526 (minus (S z0) n) y2)) \to (eq nat (plus O y2) (plus n y1)))))))) (\lambda
527 (y1: nat).(\lambda (y2: nat).(\lambda (_: (le O (S z0))).(\lambda (_: (le O
528 (S z0))).(\lambda (H1: (eq nat (S (plus z0 y1)) (S (plus z0 y2)))).(let H_y
529 \def (IH O O) in (let H2 \def (eq_ind_r nat (minus z0 O) (\lambda (n:
530 nat).(\forall (y3: nat).(\forall (y4: nat).((le O z0) \to ((le O z0) \to ((eq
531 nat (plus n y3) (plus n y4)) \to (eq nat y4 y3))))))) H_y z0 (minus_n_O z0))
532 in (H2 y1 y2 (le_O_n z0) (le_O_n z0) (H2 (plus z0 y2) (plus z0 y1) (le_O_n
533 z0) (le_O_n z0) (f_equal nat nat (plus z0) (plus z0 y2) (plus z0 y1) (sym_eq
534 nat (plus z0 y1) (plus z0 y2) (eq_add_S (plus z0 y1) (plus z0 y2)
535 H1)))))))))))) (\lambda (x3: nat).(\lambda (_: ((\forall (y1: nat).(\forall
536 (y2: nat).((le O (S z0)) \to ((le x3 (S z0)) \to ((eq nat (S (plus z0 y1))
537 (plus (match x3 with [O \Rightarrow (S z0) | (S l) \Rightarrow (minus z0 l)])
538 y2)) \to (eq nat y2 (plus x3 y1))))))))).(\lambda (y1: nat).(\lambda (y2:
539 nat).(\lambda (_: (le O (S z0))).(\lambda (H0: (le (S x3) (S z0))).(\lambda
540 (H1: (eq nat (S (plus z0 y1)) (plus (minus z0 x3) y2))).(let H_y \def (IH O
541 x3 (S y1)) in (let H2 \def (eq_ind_r nat (minus z0 O) (\lambda (n:
542 nat).(\forall (y3: nat).((le O z0) \to ((le x3 z0) \to ((eq nat (plus n (S
543 y1)) (plus (minus z0 x3) y3)) \to (eq nat y3 (plus x3 (S y1)))))))) H_y z0
544 (minus_n_O z0)) in (let H3 \def (eq_ind_r nat (plus z0 (S y1)) (\lambda (n:
545 nat).(\forall (y3: nat).((le O z0) \to ((le x3 z0) \to ((eq nat n (plus
546 (minus z0 x3) y3)) \to (eq nat y3 (plus x3 (S y1)))))))) H2 (S (plus z0 y1))
547 (plus_n_Sm z0 y1)) in (let H4 \def (eq_ind_r nat (plus x3 (S y1)) (\lambda
548 (n: nat).(\forall (y3: nat).((le O z0) \to ((le x3 z0) \to ((eq nat (S (plus
549 z0 y1)) (plus (minus z0 x3) y3)) \to (eq nat y3 n)))))) H3 (S (plus x3 y1))
550 (plus_n_Sm x3 y1)) in (H4 y2 (le_O_n z0) (le_S_n x3 z0 H0) H1))))))))))))
551 x2)) (\lambda (x2: nat).(\lambda (_: ((\forall (x3: nat).(\forall (y1:
552 nat).(\forall (y2: nat).((le x2 (S z0)) \to ((le x3 (S z0)) \to ((eq nat
553 (plus (minus (S z0) x2) y1) (plus (minus (S z0) x3) y2)) \to (eq nat (plus x2
554 y2) (plus x3 y1)))))))))).(\lambda (x3: nat).(nat_ind (\lambda (n:
555 nat).(\forall (y1: nat).(\forall (y2: nat).((le (S x2) (S z0)) \to ((le n (S
556 z0)) \to ((eq nat (plus (minus (S z0) (S x2)) y1) (plus (minus (S z0) n) y2))
557 \to (eq nat (plus (S x2) y2) (plus n y1)))))))) (\lambda (y1: nat).(\lambda
558 (y2: nat).(\lambda (H: (le (S x2) (S z0))).(\lambda (_: (le O (S
559 z0))).(\lambda (H1: (eq nat (plus (minus z0 x2) y1) (S (plus z0 y2)))).(let
560 H_y \def (IH x2 O y1 (S y2)) in (let H2 \def (eq_ind_r nat (minus z0 O)
561 (\lambda (n: nat).((le x2 z0) \to ((le O z0) \to ((eq nat (plus (minus z0 x2)
562 y1) (plus n (S y2))) \to (eq nat (plus x2 (S y2)) y1))))) H_y z0 (minus_n_O
563 z0)) in (let H3 \def (eq_ind_r nat (plus z0 (S y2)) (\lambda (n: nat).((le x2
564 z0) \to ((le O z0) \to ((eq nat (plus (minus z0 x2) y1) n) \to (eq nat (plus
565 x2 (S y2)) y1))))) H2 (S (plus z0 y2)) (plus_n_Sm z0 y2)) in (let H4 \def
566 (eq_ind_r nat (plus x2 (S y2)) (\lambda (n: nat).((le x2 z0) \to ((le O z0)
567 \to ((eq nat (plus (minus z0 x2) y1) (S (plus z0 y2))) \to (eq nat n y1)))))
568 H3 (S (plus x2 y2)) (plus_n_Sm x2 y2)) in (H4 (le_S_n x2 z0 H) (le_O_n z0)
569 H1)))))))))) (\lambda (x4: nat).(\lambda (_: ((\forall (y1: nat).(\forall
570 (y2: nat).((le (S x2) (S z0)) \to ((le x4 (S z0)) \to ((eq nat (plus (minus
571 z0 x2) y1) (plus (match x4 with [O \Rightarrow (S z0) | (S l) \Rightarrow
572 (minus z0 l)]) y2)) \to (eq nat (S (plus x2 y2)) (plus x4
573 y1))))))))).(\lambda (y1: nat).(\lambda (y2: nat).(\lambda (H: (le (S x2) (S
574 z0))).(\lambda (H0: (le (S x4) (S z0))).(\lambda (H1: (eq nat (plus (minus z0
575 x2) y1) (plus (minus z0 x4) y2))).(f_equal nat nat S (plus x2 y2) (plus x4
576 y1) (IH x2 x4 y1 y2 (le_S_n x2 z0 H) (le_S_n x4 z0 H0) H1))))))))) x3))))
580 \forall (d: nat).(\forall (h: nat).(\forall (n: nat).((le (plus d h) n) \to
581 (le d (S (minus n h))))))
583 \lambda (d: nat).(\lambda (h: nat).(\lambda (n: nat).(\lambda (H: (le (plus
584 d h) n)).(let H0 \def (le_trans d (plus d h) n (le_plus_l d h) H) in (let H1
585 \def (eq_ind nat n (\lambda (n0: nat).(le d n0)) H0 (plus (minus n h) h)
586 (le_plus_minus_sym h n (le_trans_plus_r d h n H))) in (le_S d (minus n h)
587 (le_minus d n h H))))))).