--- /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/nat/generic_iter_p.ma".
+
+include "nat/primes.ma".
+include "nat/ord.ma".
+
+
+
+(*a generic definition of summatory indexed over natural numbers:
+ * n:N is the advanced end in the range of the sommatory
+ * p: N -> bool is a predicate. if (p i) = true, then (g i) is summed, else it isn't
+ * A is the type of the elements of the sum.
+ * g:nat -> A, is the function which associates the nth element of the sum to the nth natural numbers
+ * baseA (of type A) is the neutral element of A for plusA operation
+ * plusA: A -> A -> A is the sum over elements in A.
+ *)
+let rec iter_p_gen (n:nat) (p: nat \to bool) (A:Type) (g: nat \to A)
+ (baseA: A) (plusA: A \to A \to A) \def
+ match n with
+ [ O \Rightarrow baseA
+ | (S k) \Rightarrow
+ match p k with
+ [true \Rightarrow (plusA (g k) (iter_p_gen k p A g baseA plusA))
+ |false \Rightarrow iter_p_gen k p A g baseA plusA]
+ ].
+
+theorem true_to_iter_p_gen_Sn:
+\forall n:nat. \forall p:nat \to bool. \forall A:Type. \forall g:nat \to A.
+\forall baseA:A. \forall plusA: A \to A \to A.
+p n = true \to iter_p_gen (S n) p A g baseA plusA =
+(plusA (g n) (iter_p_gen n p A g baseA plusA)).
+intros.
+simplify.
+rewrite > H.
+reflexivity.
+qed.
+
+
+
+theorem false_to_iter_p_gen_Sn:
+\forall n:nat. \forall p:nat \to bool. \forall A:Type. \forall g:nat \to A.
+\forall baseA:A. \forall plusA: A \to A \to A.
+p n = false \to iter_p_gen (S n) p A g baseA plusA = iter_p_gen n p A g baseA plusA.
+intros.
+simplify.
+rewrite > H.
+reflexivity.
+qed.
+
+
+theorem eq_iter_p_gen: \forall p1,p2:nat \to bool. \forall A:Type.
+\forall g1,g2: nat \to A. \forall baseA: A.
+\forall plusA: A \to A \to A. \forall n:nat.
+(\forall x. x < n \to p1 x = p2 x) \to
+(\forall x. x < n \to g1 x = g2 x) \to
+iter_p_gen n p1 A g1 baseA plusA = iter_p_gen n p2 A g2 baseA plusA.
+intros 8.
+elim n
+[ reflexivity
+| apply (bool_elim ? (p1 n1))
+ [ intro.
+ rewrite > (true_to_iter_p_gen_Sn ? ? ? ? ? ? H3).
+ rewrite > true_to_iter_p_gen_Sn
+ [ apply eq_f2
+ [ apply H2.apply le_n.
+ | apply H
+ [ intros.apply H1.apply le_S.assumption
+ | intros.apply H2.apply le_S.assumption
+ ]
+ ]
+ | rewrite < H3.apply sym_eq.apply H1.apply le_n
+ ]
+ | intro.
+ rewrite > (false_to_iter_p_gen_Sn ? ? ? ? ? ? H3).
+ rewrite > false_to_iter_p_gen_Sn
+ [ apply H
+ [ intros.apply H1.apply le_S.assumption
+ | intros.apply H2.apply le_S.assumption
+ ]
+ | rewrite < H3.apply sym_eq.apply H1.apply le_n
+ ]
+ ]
+]
+qed.
+
+theorem eq_iter_p_gen1: \forall p1,p2:nat \to bool. \forall A:Type.
+\forall g1,g2: nat \to A. \forall baseA: A.
+\forall plusA: A \to A \to A.\forall n:nat.
+(\forall x. x < n \to p1 x = p2 x) \to
+(\forall x. x < n \to p1 x = true \to g1 x = g2 x) \to
+iter_p_gen n p1 A g1 baseA plusA = iter_p_gen n p2 A g2 baseA plusA.
+intros 8.
+elim n
+[ reflexivity
+| apply (bool_elim ? (p1 n1))
+ [ intro.
+ rewrite > (true_to_iter_p_gen_Sn ? ? ? ? ? ? H3).
+ rewrite > true_to_iter_p_gen_Sn
+ [ apply eq_f2
+ [ apply H2
+ [ apply le_n
+ | assumption
+ ]
+ | apply H
+ [ intros.apply H1.apply le_S.assumption
+ | intros.apply H2
+ [ apply le_S.assumption
+ | assumption
+ ]
+ ]
+ ]
+ | rewrite < H3.
+ apply sym_eq.apply H1.apply le_n
+ ]
+ | intro.
+ rewrite > (false_to_iter_p_gen_Sn ? ? ? ? ? ? H3).
+ rewrite > false_to_iter_p_gen_Sn
+ [ apply H
+ [ intros.apply H1.apply le_S.assumption
+ | intros.apply H2
+ [ apply le_S.assumption
+ | assumption
+ ]
+ ]
+ | rewrite < H3.apply sym_eq.
+ apply H1.apply le_n
+ ]
+ ]
+]
+qed.
+
+theorem iter_p_gen_false: \forall A:Type. \forall g: nat \to A. \forall baseA:A.
+\forall plusA: A \to A \to A. \forall n.
+iter_p_gen n (\lambda x.false) A g baseA plusA = baseA.
+intros.
+elim n
+[ reflexivity
+| simplify.
+ assumption
+]
+qed.
+
+theorem iter_p_gen_plusA: \forall A:Type. \forall n,k:nat.\forall p:nat \to bool.
+\forall g: nat \to A. \forall baseA:A. \forall plusA: A \to A \to A.
+(symmetric A plusA) \to (\forall a:A. (plusA a baseA) = a) \to (associative A plusA)
+\to
+iter_p_gen (k + n) p A g baseA plusA
+= (plusA (iter_p_gen k (\lambda x.p (x+n)) A (\lambda x.g (x+n)) baseA plusA)
+ (iter_p_gen n p A g baseA plusA)).
+intros.
+
+elim k
+[ rewrite < (plus_n_O n).
+ simplify.
+ rewrite > H in \vdash (? ? ? %).
+ rewrite > (H1 ?).
+ reflexivity
+| apply (bool_elim ? (p (n1+n)))
+ [ intro.
+ rewrite > (true_to_iter_p_gen_Sn ? ? ? ? ? ? H4).
+ rewrite > (true_to_iter_p_gen_Sn n1 (\lambda x.p (x+n)) ? ? ? ? H4).
+ rewrite > (H2 (g (n1 + n)) ? ?).
+ rewrite < H3.
+ reflexivity
+ | intro.
+ rewrite > (false_to_iter_p_gen_Sn ? ? ? ? ? ? H4).
+ rewrite > (false_to_iter_p_gen_Sn n1 (\lambda x.p (x+n)) ? ? ? ? H4).
+ assumption
+ ]
+]
+qed.
+
+theorem false_to_eq_iter_p_gen: \forall A:Type. \forall n,m:nat.\forall p:nat \to bool.
+\forall g: nat \to A. \forall baseA:A. \forall plusA: A \to A \to A.
+n \le m \to (\forall i:nat. n \le i \to i < m \to p i = false)
+\to iter_p_gen m p A g baseA plusA = iter_p_gen n p A g baseA plusA.
+intros 8.
+elim H
+[ reflexivity
+| simplify.
+ rewrite > H3
+ [ simplify.
+ apply H2.
+ intros.
+ apply H3
+ [ apply H4
+ | apply le_S.
+ assumption
+ ]
+ | assumption
+ |apply le_n
+ ]
+]
+qed.
+
+theorem iter_p_gen2 :
+\forall n,m:nat.
+\forall p1,p2:nat \to bool.
+\forall A:Type.
+\forall g: nat \to nat \to A.
+\forall baseA: A.
+\forall plusA: A \to A \to A.
+(symmetric A plusA) \to (associative A plusA) \to (\forall a:A.(plusA a baseA) = a)
+\to
+iter_p_gen (n*m)
+ (\lambda x.andb (p1 (div x m)) (p2 (mod x m)))
+ A
+ (\lambda x.g (div x m) (mod x m))
+ baseA
+ plusA =
+iter_p_gen n p1 A
+ (\lambda x.iter_p_gen m p2 A (g x) baseA plusA)
+ baseA plusA.
+intros.
+elim n
+[ simplify.
+ reflexivity
+| apply (bool_elim ? (p1 n1))
+ [ intro.
+ rewrite > (true_to_iter_p_gen_Sn ? ? ? ? ? ? H4).
+ simplify in \vdash (? ? (? % ? ? ? ? ?) ?).
+ rewrite > iter_p_gen_plusA
+ [ rewrite < H3.
+ apply eq_f2
+ [ apply eq_iter_p_gen
+ [ intros.
+ rewrite > sym_plus.
+ rewrite > (div_plus_times ? ? ? H5).
+ rewrite > (mod_plus_times ? ? ? H5).
+ rewrite > H4.
+ simplify.
+ reflexivity
+ | intros.
+ rewrite > sym_plus.
+ rewrite > (div_plus_times ? ? ? H5).
+ rewrite > (mod_plus_times ? ? ? H5).
+ rewrite > H4.
+ simplify.reflexivity.
+ ]
+ | reflexivity
+ ]
+ | assumption
+ | assumption
+ | assumption
+ ]
+ | intro.
+ rewrite > (false_to_iter_p_gen_Sn ? ? ? ? ? ? H4).
+ simplify in \vdash (? ? (? % ? ? ? ? ?) ?).
+ rewrite > iter_p_gen_plusA
+ [ rewrite > H3.
+ apply (trans_eq ? ? (plusA baseA
+ (iter_p_gen n1 p1 A (\lambda x:nat.iter_p_gen m p2 A (g x) baseA plusA) baseA plusA )))
+ [ apply eq_f2
+ [ rewrite > (eq_iter_p_gen ? (\lambda x.false) A ? (\lambda x:nat.g ((x+n1*m)/m) ((x+n1*m)\mod m)))
+ [ apply iter_p_gen_false
+ | intros.
+ rewrite > sym_plus.
+ rewrite > (div_plus_times ? ? ? H5).
+ rewrite > (mod_plus_times ? ? ? H5).
+ rewrite > H4.
+ simplify.reflexivity
+ | intros.reflexivity.
+ ]
+ | reflexivity
+ ]
+ | rewrite < H.
+ rewrite > H2.
+ reflexivity.
+ ]
+ | assumption
+ | assumption
+ | assumption
+ ]
+ ]
+]
+qed.
+
+
+theorem iter_p_gen2':
+\forall n,m:nat.
+\forall p1: nat \to bool.
+\forall p2: nat \to nat \to bool.
+\forall A:Type.
+\forall g: nat \to nat \to A.
+\forall baseA: A.
+\forall plusA: A \to A \to A.
+(symmetric A plusA) \to (associative A plusA) \to (\forall a:A.(plusA a baseA) = a)
+\to
+iter_p_gen (n*m)
+ (\lambda x.andb (p1 (div x m)) (p2 (div x m)(mod x m)))
+ A
+ (\lambda x.g (div x m) (mod x m))
+ baseA
+ plusA =
+iter_p_gen n p1 A
+ (\lambda x.iter_p_gen m (p2 x) A (g x) baseA plusA)
+ baseA plusA.
+intros.
+elim n
+[ simplify.
+ reflexivity
+| apply (bool_elim ? (p1 n1))
+ [ intro.
+ rewrite > (true_to_iter_p_gen_Sn ? ? ? ? ? ? H4).
+ simplify in \vdash (? ? (? % ? ? ? ? ?) ?).
+ rewrite > iter_p_gen_plusA
+ [ rewrite < H3.
+ apply eq_f2
+ [ apply eq_iter_p_gen
+ [ intros.
+ rewrite > sym_plus.
+ rewrite > (div_plus_times ? ? ? H5).
+ rewrite > (mod_plus_times ? ? ? H5).
+ rewrite > H4.
+ simplify.
+ reflexivity
+ | intros.
+ rewrite > sym_plus.
+ rewrite > (div_plus_times ? ? ? H5).
+ rewrite > (mod_plus_times ? ? ? H5).
+ rewrite > H4.
+ simplify.reflexivity.
+ ]
+ | reflexivity
+ ]
+ | assumption
+ | assumption
+ | assumption
+ ]
+ | intro.
+ rewrite > (false_to_iter_p_gen_Sn ? ? ? ? ? ? H4).
+ simplify in \vdash (? ? (? % ? ? ? ? ?) ?).
+ rewrite > iter_p_gen_plusA
+ [ rewrite > H3.
+ apply (trans_eq ? ? (plusA baseA
+ (iter_p_gen n1 p1 A (\lambda x:nat.iter_p_gen m (p2 x) A (g x) baseA plusA) baseA plusA )))
+ [ apply eq_f2
+ [ rewrite > (eq_iter_p_gen ? (\lambda x.false) A ? (\lambda x:nat.g ((x+n1*m)/m) ((x+n1*m)\mod m)))
+ [ apply iter_p_gen_false
+ | intros.
+ rewrite > sym_plus.
+ rewrite > (div_plus_times ? ? ? H5).
+ rewrite > (mod_plus_times ? ? ? H5).
+ rewrite > H4.
+ simplify.reflexivity
+ | intros.reflexivity.
+ ]
+ | reflexivity
+ ]
+ | rewrite < H.
+ rewrite > H2.
+ reflexivity.
+ ]
+ | assumption
+ | assumption
+ | assumption
+ ]
+ ]
+]
+qed.
+
+lemma iter_p_gen_gi:
+\forall A:Type.
+\forall g: nat \to A.
+\forall baseA:A.
+\forall plusA: A \to A \to A.
+\forall n,i:nat.
+\forall p:nat \to bool.
+(symmetric A plusA) \to (associative A plusA) \to (\forall a:A.(plusA a baseA) = a)
+ \to
+
+i < n \to p i = true \to
+(iter_p_gen n p A g baseA plusA) =
+(plusA (g i) (iter_p_gen n (\lambda x:nat. andb (p x) (notb (eqb x i))) A g baseA plusA)).
+intros 5.
+elim n
+[ apply False_ind.
+ apply (not_le_Sn_O i).
+ assumption
+| apply (bool_elim ? (p n1));intro
+ [ elim (le_to_or_lt_eq i n1)
+ [ rewrite > true_to_iter_p_gen_Sn
+ [ rewrite > true_to_iter_p_gen_Sn
+ [ rewrite < (H2 (g i) ? ?).
+ rewrite > (H1 (g i) (g n1)).
+ rewrite > (H2 (g n1) ? ?).
+ apply eq_f2
+ [ reflexivity
+ | apply H
+ [ assumption
+ | assumption
+ | assumption
+ | assumption
+ | assumption
+ ]
+ ]
+ | rewrite > H6.simplify.
+ change with (notb (eqb n1 i) = notb false).
+ apply eq_f.
+ apply not_eq_to_eqb_false.
+ unfold Not.intro.
+ apply (lt_to_not_eq ? ? H7).
+ apply sym_eq.assumption
+ ]
+ | assumption
+ ]
+ | rewrite > true_to_iter_p_gen_Sn
+ [ rewrite > H7.
+ apply eq_f2
+ [ reflexivity
+ | rewrite > false_to_iter_p_gen_Sn
+ [ apply eq_iter_p_gen
+ [ intros.
+ elim (p x)
+ [ simplify.
+ change with (notb false = notb (eqb x n1)).
+ apply eq_f.
+ apply sym_eq.
+ apply not_eq_to_eqb_false.
+ apply (lt_to_not_eq ? ? H8)
+ | reflexivity
+ ]
+ | intros.
+ reflexivity
+ ]
+ | rewrite > H6.
+ rewrite > (eq_to_eqb_true ? ? (refl_eq ? n1)).
+ reflexivity
+ ]
+ ]
+ | assumption
+ ]
+ | apply le_S_S_to_le.
+ assumption
+ ]
+ | rewrite > false_to_iter_p_gen_Sn
+ [ elim (le_to_or_lt_eq i n1)
+ [ rewrite > false_to_iter_p_gen_Sn
+ [ apply H
+ [ assumption
+ | assumption
+ | assumption
+ | assumption
+ | assumption
+ ]
+ | rewrite > H6.reflexivity
+ ]
+ | apply False_ind.
+ apply not_eq_true_false.
+ rewrite < H5.
+ rewrite > H7.
+ assumption
+ | apply le_S_S_to_le.
+ assumption
+ ]
+ | assumption
+ ]
+ ]
+]
+qed.
+
+
+theorem eq_iter_p_gen_gh:
+\forall A:Type.
+\forall baseA: A.
+\forall plusA: A \to A \to A.
+(symmetric A plusA) \to (associative A plusA) \to (\forall a:A.(plusA a baseA) = a) \to
+\forall g: nat \to A.
+\forall h,h1: nat \to nat.
+\forall n,n1:nat.
+\forall p1,p2:nat \to bool.
+(\forall i. i < n \to p1 i = true \to p2 (h i) = true) \to
+(\forall i. i < n \to p1 i = true \to h1 (h i) = i) \to
+(\forall i. i < n \to p1 i = true \to h i < n1) \to
+(\forall j. j < n1 \to p2 j = true \to p1 (h1 j) = true) \to
+(\forall j. j < n1 \to p2 j = true \to h (h1 j) = j) \to
+(\forall j. j < n1 \to p2 j = true \to h1 j < n) \to
+
+iter_p_gen n p1 A (\lambda x.g(h x)) baseA plusA =
+iter_p_gen n1 (\lambda x.p2 x) A g baseA plusA.
+intros 10.
+elim n
+[ generalize in match H8.
+ elim n1
+ [ reflexivity
+ | apply (bool_elim ? (p2 n2));intro
+ [ apply False_ind.
+ apply (not_le_Sn_O (h1 n2)).
+ apply H10
+ [ apply le_n
+ | assumption
+ ]
+ | rewrite > false_to_iter_p_gen_Sn
+ [ apply H9.
+ intros.
+ apply H10
+ [ apply le_S.
+ apply H12
+ | assumption
+ ]
+ | assumption
+ ]
+ ]
+ ]
+| apply (bool_elim ? (p1 n1));intro
+ [ rewrite > true_to_iter_p_gen_Sn
+ [ rewrite > (iter_p_gen_gi A g baseA plusA n2 (h n1))
+ [ apply eq_f2
+ [ reflexivity
+ | apply H3
+ [ intros.
+ rewrite > H4
+ [ simplify.
+ change with ((\not eqb (h i) (h n1))= \not false).
+ apply eq_f.
+ apply not_eq_to_eqb_false.
+ unfold Not.
+ intro.
+ apply (lt_to_not_eq ? ? H11).
+ rewrite < H5
+ [ rewrite < (H5 n1)
+ [ apply eq_f.
+ assumption
+ | apply le_n
+ | assumption
+ ]
+ | apply le_S.
+ assumption
+ | assumption
+ ]
+ | apply le_S.assumption
+ | assumption
+ ]
+ | intros.
+ apply H5
+ [ apply le_S.
+ assumption
+ | assumption
+ ]
+ | intros.
+ apply H6
+ [ apply le_S.assumption
+ | assumption
+ ]
+ | intros.
+ apply H7
+ [ assumption
+ | generalize in match H12.
+ elim (p2 j)
+ [ reflexivity
+ | assumption
+ ]
+ ]
+ | intros.
+ apply H8
+ [ assumption
+ | generalize in match H12.
+ elim (p2 j)
+ [ reflexivity
+ | assumption
+ ]
+ ]
+ | intros.
+ elim (le_to_or_lt_eq (h1 j) n1)
+ [ assumption
+ | generalize in match H12.
+ elim (p2 j)
+ [ simplify in H13.
+ absurd (j = (h n1))
+ [ rewrite < H13.
+ rewrite > H8
+ [ reflexivity
+ | assumption
+ | autobatch
+ ]
+ | apply eqb_false_to_not_eq.
+ generalize in match H14.
+ elim (eqb j (h n1))
+ [ apply sym_eq.assumption
+ | reflexivity
+ ]
+ ]
+ | simplify in H14.
+ apply False_ind.
+ apply not_eq_true_false.
+ apply sym_eq.assumption
+ ]
+ | apply le_S_S_to_le.
+ apply H9
+ [ assumption
+ | generalize in match H12.
+ elim (p2 j)
+ [ reflexivity
+ | assumption
+ ]
+ ]
+ ]
+ ]
+ ]
+ | assumption
+ | assumption
+ | assumption
+ | apply H6
+ [ apply le_n
+ | assumption
+ ]
+ | apply H4
+ [ apply le_n
+ | assumption
+ ]
+ ]
+ | assumption
+ ]
+ | rewrite > false_to_iter_p_gen_Sn
+ [ apply H3
+ [ intros.
+ apply H4[apply le_S.assumption|assumption]
+ | intros.
+ apply H5[apply le_S.assumption|assumption]
+ | intros.
+ apply H6[apply le_S.assumption|assumption]
+ | intros.
+ apply H7[assumption|assumption]
+ | intros.
+ apply H8[assumption|assumption]
+ | intros.
+ elim (le_to_or_lt_eq (h1 j) n1)
+ [ assumption
+ | absurd (j = (h n1))
+ [ rewrite < H13.
+ rewrite > H8
+ [ reflexivity
+ | assumption
+ | assumption
+ ]
+ | unfold Not.intro.
+ apply not_eq_true_false.
+ rewrite < H10.
+ rewrite < H13.
+ rewrite > H7
+ [ reflexivity
+ | assumption
+ | assumption
+ ]
+ ]
+ | apply le_S_S_to_le.
+ apply H9
+ [ assumption
+ | assumption
+ ]
+ ]
+ ]
+ | assumption
+ ]
+ ]
+]
+qed.
+
+
+
+definition p_ord_times \def
+\lambda p,m,x.
+ match p_ord x p with
+ [pair q r \Rightarrow r*m+q].
+
+theorem eq_p_ord_times: \forall p,m,x.
+p_ord_times p m x = (ord_rem x p)*m+(ord x p).
+intros.unfold p_ord_times. unfold ord_rem.
+unfold ord.
+elim (p_ord x p).
+reflexivity.
+qed.
+
+theorem div_p_ord_times:
+\forall p,m,x. ord x p < m \to p_ord_times p m x / m = ord_rem x p.
+intros.rewrite > eq_p_ord_times.
+apply div_plus_times.
+assumption.
+qed.
+
+theorem mod_p_ord_times:
+\forall p,m,x. ord x p < m \to p_ord_times p m x \mod m = ord x p.
+intros.rewrite > eq_p_ord_times.
+apply mod_plus_times.
+assumption.
+qed.
+
+theorem iter_p_gen_divides:
+\forall A:Type.
+\forall baseA: A.
+\forall plusA: A \to A \to A.
+\forall n,m,p:nat.O < n \to prime p \to Not (divides p n) \to
+\forall g: nat \to A.
+(symmetric A plusA) \to (associative A plusA) \to (\forall a:A.(plusA a baseA) = a)
+
+\to
+
+iter_p_gen (S (n*(exp p m))) (\lambda x.divides_b x (n*(exp p m))) A g baseA plusA =
+iter_p_gen (S n) (\lambda x.divides_b x n) A
+ (\lambda x.iter_p_gen (S m) (\lambda y.true) A (\lambda y.g (x*(exp p y))) baseA plusA) baseA plusA.
+intros.
+cut (O < p)
+ [rewrite < (iter_p_gen2 ? ? ? ? ? ? ? ? H3 H4 H5).
+ apply (trans_eq ? ?
+ (iter_p_gen (S n*S m) (\lambda x:nat.divides_b (x/S m) n) A
+ (\lambda x:nat.g (x/S m*(p)\sup(x\mod S m))) baseA plusA) )
+ [apply sym_eq.
+ apply (eq_iter_p_gen_gh ? ? ? ? ? ? g ? (p_ord_times p (S m)))
+ [ assumption
+ | assumption
+ | assumption
+ |intros.
+ lapply (divides_b_true_to_lt_O ? ? H H7).
+ apply divides_to_divides_b_true
+ [rewrite > (times_n_O O).
+ apply lt_times
+ [assumption
+ |apply lt_O_exp.assumption
+ ]
+ |apply divides_times
+ [apply divides_b_true_to_divides.assumption
+ |apply (witness ? ? (p \sup (m-i \mod (S m)))).
+ rewrite < exp_plus_times.
+ apply eq_f.
+ rewrite > sym_plus.
+ apply plus_minus_m_m.
+ autobatch
+ ]
+ ]
+ |intros.
+ lapply (divides_b_true_to_lt_O ? ? H H7).
+ unfold p_ord_times.
+ rewrite > (p_ord_exp1 p ? (i \mod (S m)) (i/S m))
+ [change with ((i/S m)*S m+i \mod S m=i).
+ apply sym_eq.
+ apply div_mod.
+ apply lt_O_S
+ |assumption
+ |unfold Not.intro.
+ apply H2.
+ apply (trans_divides ? (i/ S m))
+ [assumption|
+ apply divides_b_true_to_divides;assumption]
+ |apply sym_times.
+ ]
+ |intros.
+ apply le_S_S.
+ apply le_times
+ [apply le_S_S_to_le.
+ change with ((i/S m) < S n).
+ apply (lt_times_to_lt_l m).
+ apply (le_to_lt_to_lt ? i)
+ [autobatch|assumption]
+ |apply le_exp
+ [assumption
+ |apply le_S_S_to_le.
+ apply lt_mod_m_m.
+ apply lt_O_S
+ ]
+ ]
+ |intros.
+ cut (ord j p < S m)
+ [rewrite > div_p_ord_times
+ [apply divides_to_divides_b_true
+ [apply lt_O_ord_rem
+ [elim H1.assumption
+ |apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ ]
+ |cut (n = ord_rem (n*(exp p m)) p)
+ [rewrite > Hcut2.
+ apply divides_to_divides_ord_rem
+ [apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |assumption
+ |apply divides_b_true_to_divides.
+ assumption
+ ]
+ |unfold ord_rem.
+ rewrite > (p_ord_exp1 p ? m n)
+ [reflexivity
+ |assumption
+ |assumption
+ |apply sym_times
+ ]
+ ]
+ ]
+ |assumption
+ ]
+ |cut (m = ord (n*(exp p m)) p)
+ [apply le_S_S.
+ rewrite > Hcut1.
+ apply divides_to_le_ord
+ [apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |assumption
+ |apply divides_b_true_to_divides.
+ assumption
+ ]
+ |unfold ord.
+ rewrite > (p_ord_exp1 p ? m n)
+ [reflexivity
+ |assumption
+ |assumption
+ |apply sym_times
+ ]
+ ]
+ ]
+ |intros.
+ cut (ord j p < S m)
+ [rewrite > div_p_ord_times
+ [rewrite > mod_p_ord_times
+ [rewrite > sym_times.
+ apply sym_eq.
+ apply exp_ord
+ [elim H1.assumption
+ |apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ ]
+ |cut (m = ord (n*(exp p m)) p)
+ [apply le_S_S.
+ rewrite > Hcut2.
+ apply divides_to_le_ord
+ [apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |assumption
+ |apply divides_b_true_to_divides.
+ assumption
+ ]
+ |unfold ord.
+ rewrite > (p_ord_exp1 p ? m n)
+ [reflexivity
+ |assumption
+ |assumption
+ |apply sym_times
+ ]
+ ]
+ ]
+ |assumption
+ ]
+ |cut (m = ord (n*(exp p m)) p)
+ [apply le_S_S.
+ rewrite > Hcut1.
+ apply divides_to_le_ord
+ [apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |assumption
+ |apply divides_b_true_to_divides.
+ assumption
+ ]
+ |unfold ord.
+ rewrite > (p_ord_exp1 p ? m n)
+ [reflexivity
+ |assumption
+ |assumption
+ |apply sym_times
+ ]
+ ]
+ ]
+ |intros.
+ rewrite > eq_p_ord_times.
+ rewrite > sym_plus.
+ apply (lt_to_le_to_lt ? (S m +ord_rem j p*S m))
+ [apply lt_plus_l.
+ apply le_S_S.
+ cut (m = ord (n*(p \sup m)) p)
+ [rewrite > Hcut1.
+ apply divides_to_le_ord
+ [apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |assumption
+ |apply divides_b_true_to_divides.
+ assumption
+ ]
+ |unfold ord.
+ rewrite > sym_times.
+ rewrite > (p_ord_exp1 p ? m n)
+ [reflexivity
+ |assumption
+ |assumption
+ |reflexivity
+ ]
+ ]
+ |change with (S (ord_rem j p)*S m \le S n*S m).
+ apply le_times_l.
+ apply le_S_S.
+ cut (n = ord_rem (n*(p \sup m)) p)
+ [rewrite > Hcut1.
+ apply divides_to_le
+ [apply lt_O_ord_rem
+ [elim H1.assumption
+ |rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ ]
+ |apply divides_to_divides_ord_rem
+ [apply (divides_b_true_to_lt_O ? ? ? H7).
+ rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |rewrite > (times_n_O O).
+ apply lt_times
+ [assumption|apply lt_O_exp.assumption]
+ |assumption
+ |apply divides_b_true_to_divides.
+ assumption
+ ]
+ ]
+ |unfold ord_rem.
+ rewrite > sym_times.
+ rewrite > (p_ord_exp1 p ? m n)
+ [reflexivity
+ |assumption
+ |assumption
+ |reflexivity
+ ]
+ ]
+ ]
+ ]
+ |apply eq_iter_p_gen
+
+ [intros.
+ elim (divides_b (x/S m) n);reflexivity
+ |intros.reflexivity
+ ]
+ ]
+|elim H1.apply lt_to_le.assumption
+]
+qed.
+
+(*distributive property for iter_p_gen*)
+theorem distributive_times_plus_iter_p_gen: \forall A:Type.
+\forall plusA: A \to A \to A. \forall basePlusA: A.
+\forall timesA: A \to A \to A.
+\forall n:nat. \forall k:A. \forall p:nat \to bool. \forall g:nat \to A.
+(symmetric A plusA) \to (associative A plusA) \to (\forall a:A.(plusA a basePlusA) = a) \to
+(symmetric A timesA) \to (distributive A timesA plusA) \to
+(\forall a:A. (timesA a basePlusA) = basePlusA)
+
+ \to
+
+((timesA k (iter_p_gen n p A g basePlusA plusA)) =
+ (iter_p_gen n p A (\lambda i:nat.(timesA k (g i))) basePlusA plusA)).
+intros.
+elim n
+[ simplify.
+ apply H5
+| cut( (p n1) = true \lor (p n1) = false)
+ [ elim Hcut
+ [ rewrite > (true_to_iter_p_gen_Sn ? ? ? ? ? ? H7).
+ rewrite > (true_to_iter_p_gen_Sn ? ? ? ? ? ? H7) in \vdash (? ? ? %).
+ rewrite > (H4).
+ rewrite > (H3 k (g n1)).
+ apply eq_f.
+ assumption
+ | rewrite > (false_to_iter_p_gen_Sn ? ? ? ? ? ? H7).
+ rewrite > (false_to_iter_p_gen_Sn ? ? ? ? ? ? H7) in \vdash (? ? ? %).
+ assumption
+ ]
+ | elim ((p n1))
+ [ left.
+ reflexivity
+ | right.
+ reflexivity
+ ]
+ ]
+]
+qed.
+
+