+++ /dev/null
-(*
- ||M|| This file is part of HELM, an Hypertextual, Electronic
- ||A|| Library of Mathematics, developed at the Computer Science
- ||T|| Department of the University of Bologna, Italy.
- ||I||
- ||T||
- ||A||
- \ / This file is distributed under the terms of the
- \ / GNU General Public License Version 2
- V_____________________________________________________________*)
-
-include "arithmetics/log.ma".
-include "arithmetics/sigma_pi.ma".
-include "arithmetics/ord.ma".
-
-(* (prim n) counts the number of prime numbers up to n included *)
-definition prim ≝ λn. ∑_{i < S n | primeb i} 1.
-
-lemma le_prim_n: ∀n. prim n ≤ n.
-#n elim n // -n #n #H
-whd in ⊢ (?%?); cases (primeb (S n)) whd in ⊢ (?%?);
- [@le_S_S @H |@le_S @H]
-qed.
-
-lemma not_prime_times_2: ∀n. 1 < n → ¬prime (2*n).
-#n #ltn % * #H #H1 @(absurd (2 = 2*n))
- [@H1 // %{n} //
- |@lt_to_not_eq >(times_n_1 2) in ⊢ (?%?); @monotonic_lt_times_r //
- ]
-qed.
-
-theorem eq_prim_prim_pred: ∀n. 1 < n →
- prim (2*n) = prim (pred (2*n)).
-#n #ltn
-lapply (S_pred (2*n) ?) [>(times_n_1 0) in ⊢ (?%?); @lt_times //] #H2n
-lapply (not_prime_times_2 n ltn) #notp2n
-whd in ⊢ (??%?); >(not_prime_to_primeb_false … notp2n) whd in ⊢ (??%?);
-<H2n in ⊢ (??%?); %
-qed.
-
-theorem le_prim_n1: ∀n. 4 ≤ n →
- prim (S(2*n)) ≤ n.
-#n #le4 elim le4 -le4
- [@le_n
- |#m #le4 cut (S (2*m) = pred (2*(S m))) [normalize //] #Heq >Heq
- <eq_prim_prim_pred [2: @le_S_S @(transitive_le … le4) //]
- #H whd in ⊢ (?%?); cases (primeb (S (2*S m)))
- [@le_S_S @H |@le_S @H]
- ]
-qed.
-
-(* usefull to kill a successor in bertrand *)
-theorem le_prim_n2: ∀n. 7 ≤ n → prim (S(2*n)) ≤ pred n.
-#n #le7 elim le7 -le7
- [@le_n
- |#m #le7 cut (S (2*m) = pred (2*(S m))) [normalize //] #Heq >Heq
- <eq_prim_prim_pred [2: @le_S_S @(transitive_le … le7) //]
- #H whd in ⊢ (?%?);
- whd in ⊢ (??%); <(S_pred m) in ⊢ (??%); [2: @(transitive_le … le7) //]
- cases (primeb (S (2*S m))) [@le_S_S @H |@le_S @H]
- ]
-qed.
-
-lemma even_or_odd: ∀n.∃a.n=2*a ∨ n = S(2*a).
-#n elim n -n
- [%{0} %1 %
- |#n * #a * #Hn [%{a} %2 @eq_f @Hn | %{(S a)} %1 >Hn normalize //
- ]
-qed.
-
-(* la prova potrebbe essere migliorata *)
-theorem le_prim_n3: ∀n. 15 ≤ n →
- prim n ≤ pred (n/2).
-#n #len cases (even_or_odd (pred n)) #a * #Hpredn
- [cut (n = S (2*a)) [<Hpredn @sym_eq @S_pred @(transitive_le … len) //] #Hn
- >Hn @(transitive_le ? (pred a))
- [@le_prim_n2 @(le_times_to_le 2) [//|@le_S_S_to_le <Hn @len]
- |@monotonic_pred @le_times_to_le_div //
- ]
- |cut (n = (2*S a))
- [normalize normalize in Hpredn:(???%); <plus_n_Sm <Hpredn @sym_eq @S_pred
- @(transitive_le … len) //] #Hn
- >Hn @(transitive_le ? (pred a))
- [>eq_prim_prim_pred
- [2:@(lt_times_n_to_lt_r 2) <Hn @(transitive_le … len) //]
- <Hn >Hpredn @le_prim_n2 @le_S_S_to_le @(lt_times_n_to_lt_r 2) <Hn @len
- |@monotonic_pred @le_times_to_le_div //
- ]
- ]
-qed.
-
-(* This is chebishev psi function *)
-definition Psi: nat → nat ≝
- λn.∏_{p < S n | primeb p} (exp p (log p n)).
-
-definition psi_def : ∀n.
- Psi n = ∏_{p < S n | primeb p} (exp p (log p n)).
-// qed.
-
-theorem le_Psil1: ∀n.
- Psi n ≤ ∏_{p < S n | primeb p} n.
-#n cases n [@le_n |#m @le_pi #i #_ #_ @le_exp_log //]
-qed.
-
-theorem le_Psil: ∀n. Psi n ≤ exp n (prim n).
-#n <exp_sigma @le_Psil1
-qed.
-
-theorem lePsi_r2: ∀n.
- exp n (prim n) ≤ Psi n * Psi n.
-#n elim (le_to_or_lt_eq ?? (le_O_n n)) #Hn
- [<(exp_sigma (S n) n primeb) <times_pi
- @le_pi #i #lti #primei
- cut (1<n)
- [@(lt_to_le_to_lt … (le_S_S_to_le … lti)) @prime_to_lt_SO
- @primeb_true_to_prime //] #lt1n
- <exp_plus_times
- @(transitive_le ? (exp i (S(log i n))))
- [@lt_to_le @lt_exp_log @prime_to_lt_SO @primeb_true_to_prime //
- |@le_exp
- [@prime_to_lt_O @primeb_true_to_prime //
- |>(plus_n_O (log i n)) in ⊢ (?%?); >plus_n_Sm
- @monotonic_le_plus_r @lt_O_log //
- @le_S_S_to_le //
- ]
- ]
- |<Hn @le_n
- ]
-qed.
-
-(* an equivalent formulation for psi *)
-definition Psi': nat → nat ≝
-λn. ∏_{p < S n | primeb p} (∏_{i < log p n} p).
-
-lemma Psidef: ∀n. Psi' n = ∏_{p < S n | primeb p} (∏_{i < log p n} p).
-// qed-.
-
-theorem eq_Psi_Psi': ∀n.Psi n = Psi' n.
-#n @same_bigop // #i #lti #primebi
-@(trans_eq ? ? (exp i (∑_{x < log i n} 1)))
- [@eq_f @sym_eq @sigma_const
- |@sym_eq @exp_sigma
- ]
-qed.
-
-theorem eq_pi_p_primeb_divides_b: ∀n,m.
-∏_{p<n | primeb p ∧ dividesb p m} (exp p (ord m p))
- = ∏_{p<n | primeb p} (exp p (ord m p)).
-#n #m elim n // #n1 #Hind cases (true_or_false (primeb n1)) #Hprime
- [>bigop_Strue in ⊢ (???%); //
- cases (true_or_false (dividesb n1 m)) #Hdivides
- [>bigop_Strue [@eq_f @Hind| @true_to_andb_true //]
- |>bigop_Sfalse
- [>not_divides_to_ord_O
- [whd in ⊢ (???(?%?)); //
- |@dividesb_false_to_not_divides //
- |@primeb_true_to_prime //
- ]
- |>Hprime >Hdivides %
- ]
- ]
-|>bigop_Sfalse [>bigop_Sfalse // |>Hprime %]
-]
-qed.
-
-(* integrations to minimization *)
-theorem false_to_lt_max: ∀f,n,m.O < n →
- f n = false → max m f ≤ n → max m f < n.
-#f #n #m #posn #Hfn #Hmax cases (le_to_or_lt_eq ?? Hmax) -Hmax #Hmax
- [//
- |cases (exists_max_forall_false f m)
- [* #_ #Hfmax @False_ind @(absurd ?? not_eq_true_false) //
- |* //
- ]
- ]
-qed.
-
-(* integrations to minimization *)
-lemma lt_1_max_prime: ∀n. 1 < n →
- 1 < max (S n) (λi:nat.primeb i∧dividesb i n).
-#n #lt1n
-@(lt_to_le_to_lt ? (smallest_factor n))
- [@lt_SO_smallest_factor //
- |@true_to_le_max
- [@le_S_S @le_smallest_factor_n
- |@true_to_andb_true
- [@prime_to_primeb_true @prime_smallest_factor_n //
- |@divides_to_dividesb_true
- [@lt_O_smallest_factor @lt_to_le //
- |@divides_smallest_factor_n @lt_to_le //
- ]
- ]
- ]
- ]
-qed.
-
-theorem lt_max_to_pi_p_primeb: ∀q,m. O<m → max (S m) (λi.primeb i ∧ dividesb i m)<q →
- m = ∏_{p < q | primeb p ∧ dividesb p m} (exp p (ord m p)).
-#q elim q
- [#m #posm #Hmax normalize @False_ind @(absurd … Hmax (not_le_Sn_O ?))
- |#n #Hind #m #posm #Hmax
- cases (true_or_false (primeb n∧dividesb n m)) #Hcase
- [>bigop_Strue
- [>(exp_ord n m … posm) in ⊢ (??%?);
- [@eq_f >(Hind (ord_rem m n))
- [@same_bigop
- [#x #ltxn cases (true_or_false (primeb x)) #Hx >Hx
- [cases (true_or_false (dividesb x (ord_rem m n))) #Hx1 >Hx1
- [@sym_eq @divides_to_dividesb_true
- [@prime_to_lt_O @primeb_true_to_prime //
- |@(transitive_divides ? (ord_rem m n))
- [@dividesb_true_to_divides //
- |@(divides_ord_rem … posm) @(transitive_lt … ltxn)
- @prime_to_lt_SO @primeb_true_to_prime //
- ]
- ]
- |@sym_eq @not_divides_to_dividesb_false
- [@prime_to_lt_O @primeb_true_to_prime //
- |@(ord_O_to_not_divides … posm)
- [@primeb_true_to_prime //
- |<(ord_ord_rem n … posm … ltxn)
- [@not_divides_to_ord_O
- [@primeb_true_to_prime //
- |@dividesb_false_to_not_divides //
- ]
- |@primeb_true_to_prime //
- |@primeb_true_to_prime @(andb_true_l ?? Hcase)
- ]
- ]
- ]
- ]
- |//
- ]
- |#x #ltxn #Hx @eq_f @ord_ord_rem //
- [@primeb_true_to_prime @(andb_true_l ? ? Hcase)
- |@primeb_true_to_prime @(andb_true_l ? ? Hx)
- ]
- ]
- |@not_eq_to_le_to_lt
- [elim (exists_max_forall_false (λi:nat.primeb i∧dividesb i (ord_rem m n)) (S(ord_rem m n)))
- [* #Hex #Hord_rem cases Hex #x * #H6 #H7 % #H
- >H in Hord_rem; #Hn @(absurd ?? (not_divides_ord_rem m n posm ?))
- [@dividesb_true_to_divides @(andb_true_r ?? Hn)
- |@prime_to_lt_SO @primeb_true_to_prime @(andb_true_l ?? Hn)
- ]
- |* #Hall #Hmax >Hmax @lt_to_not_eq @prime_to_lt_O
- @primeb_true_to_prime @(andb_true_l ?? Hcase)
- ]
- |@(transitive_le ? (max (S m) (λi:nat.primeb i∧dividesb i (ord_rem m n))))
- [@le_to_le_max @le_S_S @(divides_to_le … posm) @(divides_ord_rem … posm)
- @prime_to_lt_SO @primeb_true_to_prime @(andb_true_l ?? Hcase)
- |@(transitive_le ? (max (S m) (λi:nat.primeb i∧dividesb i m)))
- [@le_max_f_max_g #i #ltim #Hi
- cases (true_or_false (primeb i)) #Hprimei >Hprimei
- [@divides_to_dividesb_true
- [@prime_to_lt_O @primeb_true_to_prime //
- |@(transitive_divides ? (ord_rem m n))
- [@dividesb_true_to_divides @(andb_true_r ?? Hi)
- |@(divides_ord_rem … posm)
- @prime_to_lt_SO @primeb_true_to_prime
- @(andb_true_l ?? Hcase)
- ]
- ]
- |>Hprimei in Hi; #Hi @Hi
- ]
- |@le_S_S_to_le //
- ]
- ]
- ]
- |@(lt_O_ord_rem … posm) @prime_to_lt_SO
- @primeb_true_to_prime @(andb_true_l ?? Hcase)
- ]
- |@prime_to_lt_SO @primeb_true_to_prime @(andb_true_l ?? Hcase)
- ]
- |//
- ]
- |cases (le_to_or_lt_eq ?? posm) #Hm
- [>bigop_Sfalse
- [@(Hind … posm) @false_to_lt_max
- [@(lt_to_le_to_lt ? (max (S m) (λi:nat.primeb i∧dividesb i m)))
- [@lt_to_le @lt_1_max_prime //
- |@le_S_S_to_le //
- ]
- |//
- |@le_S_S_to_le //
- ]
- |@Hcase
- ]
- |<Hm
- <(bigop_false (S n) ? 1 times (λp:nat.p\sup(ord 1 p))) in ⊢ (??%?);
- @same_bigop
- [#i #lein cases (true_or_false (primeb i)) #primei >primei //
- @sym_eq @not_divides_to_dividesb_false
- [@prime_to_lt_O @primeb_true_to_prime //
- |% #divi @(absurd ?? (le_to_not_lt i 1 ?))
- [@prime_to_lt_SO @(primeb_true_to_prime ? primei)
- |@divides_to_le //
- ]
- ]
- |//
- ]
- ]
- ]
- ]
-qed.
-
-(* factorization of n into primes *)
-theorem pi_p_primeb_dividesb: ∀n. O < n →
- n = ∏_{ p < S n | primeb p ∧ dividesb p n} (exp p (ord n p)).
-#n #posn @lt_max_to_pi_p_primeb // @lt_max_n @le_S @posn
-qed.
-
-theorem pi_p_primeb: ∀n. O < n →
- n = ∏_{ p < (S n) | primeb p}(exp p (ord n p)).
-#n #posn <eq_pi_p_primeb_divides_b @pi_p_primeb_dividesb //
-qed.
-
-(* more result on order functions *)
-theorem le_ord_log: ∀n,p. O < n → 1 < p →
- ord n p ≤ log p n.
-#n #p #posn #lt1p >(exp_ord p ? lt1p posn) in ⊢ (??(??%));
->log_exp // @lt_O_ord_rem //
-qed.
-
-theorem sigma_p_dividesb:
-∀m,n,p. O < n → prime p → p ∤ n →
-m = ∑_{ i < m | dividesb (p\sup (S i)) ((exp p m)*n)} 1.
-#m elim m // -m #m #Hind #n #p #posn #primep #ndivp
->bigop_Strue
- [>commutative_plus <plus_n_Sm @eq_f <plus_n_O
- >(Hind n p posn primep ndivp) in ⊢ (? ? % ?);
- @same_bigop
- [#i #ltim cases (true_or_false (dividesb (p\sup(S i)) (p\sup m*n))) #Hc >Hc
- [@sym_eq @divides_to_dividesb_true
- [@lt_O_exp @prime_to_lt_O //
- |%{((exp p (m - i))*n)} <associative_times
- <exp_plus_times @eq_f2 // @eq_f normalize @eq_f >commutative_plus
- @plus_minus_m_m @lt_to_le //
- ]
- |@False_ind @(absurd ?? (dividesb_false_to_not_divides ? ? Hc))
- %{((exp p (m - S i))*n)} <associative_times <exp_plus_times @eq_f2
- [@eq_f >commutative_plus @plus_minus_m_m //
- assumption
- |%
- ]
- ]
- |//
- ]
- |@divides_to_dividesb_true
- [@lt_O_exp @prime_to_lt_O // | %{n} //]
- ]
-qed.
-
-theorem sigma_p_dividesb1:
-∀m,n,p,k. O < n → prime p → p ∤ n → m ≤ k →
- m = ∑_{i < k | dividesb (p\sup (S i)) ((exp p m)*n)} 1.
-#m #n #p #k #posn #primep #ndivp #lemk
-lapply (prime_to_lt_SO ? primep) #lt1p
-lapply (prime_to_lt_O ? primep) #posp
->(sigma_p_dividesb m n p posn primep ndivp) in ⊢ (??%?);
->(pad_bigop k m) // @same_bigop
- [#i #ltik cases (true_or_false (leb m i)) #Him > Him
- [whd in ⊢(??%?); @sym_eq
- @not_divides_to_dividesb_false
- [@lt_O_exp //
- |lapply (leb_true_to_le … Him) -Him #Him
- % #Hdiv @(absurd ?? (le_to_not_lt ?? Him))
- (* <(ord_exp p m lt1p) *) >(plus_n_O m)
- <(not_divides_to_ord_O ?? primep ndivp)
- <(ord_exp p m lt1p)
- <ord_times //
- [whd <(ord_exp p (S i) lt1p)
- @divides_to_le_ord //
- [@lt_O_exp //
- |>(times_n_O O) @lt_times // @lt_O_exp //
- ]
- |@lt_O_exp //
- ]
- ]
- |%
- ]
- |//
- ]
-qed.
-
-theorem eq_ord_sigma_p:
-∀n,m,x. O < n → prime x →
-exp x m ≤ n → n < exp x (S m) →
-ord n x= ∑_{i < m | dividesb (x\sup (S i)) n} 1.
-#n #m #x #posn #primex #Hexp #ltn
-lapply (prime_to_lt_SO ? primex) #lt1x
->(exp_ord x n) in ⊢ (???%); // @sigma_p_dividesb1
- [@lt_O_ord_rem //
- |//
- |@not_divides_ord_rem //
- |@le_S_S_to_le @(le_to_lt_to_lt ? (log x n))
- [@le_ord_log //
- |@(lt_exp_to_lt x)
- [@lt_to_le //
- |@(le_to_lt_to_lt ? n ? ? ltn) @le_exp_log //
- ]
- ]
- ]
-qed.
-
-theorem pi_p_primeb1: ∀n. O < n →
-n = ∏_{p < S n| primeb p}
- (∏_{i < log p n| dividesb (exp p (S i)) n} p).
-#n #posn >(pi_p_primeb n posn) in ⊢ (??%?);
-@same_bigop
- [//
- |#p #ltp #primep >exp_sigma @eq_f @eq_ord_sigma_p
- [//
- |@primeb_true_to_prime //
- |@le_exp_log //
- |@lt_exp_log @prime_to_lt_SO @primeb_true_to_prime //
- ]
- ]
-qed.
-
-(* the factorial function *)
-theorem eq_fact_pi_p:∀n.
- fact n = ∏_{i < S n | leb 1 i} i.
-#n elim n // #n1 #Hind whd in ⊢ (??%?); >commutative_times >bigop_Strue
- [@eq_f // | % ]
-qed.
-
-theorem eq_sigma_p_div: ∀n,q.O < q →
- ∑_{ m < S n | leb (S O) m ∧ dividesb q m} 1 =n/q.
-#n #q #posq
-@(div_mod_spec_to_eq n q ? (n \mod q) ? (n \mod q))
- [@div_mod_spec_intro
- [@lt_mod_m_m //
- |elim n
- [normalize cases q //
- |#n1 #Hind cases (or_div_mod1 n1 q posq)
- [* #divq #eqn1 >divides_to_mod_O //
- <plus_n_O >bigop_Strue
- [>eqn1 in ⊢ (??%?); @eq_f2
- [<commutative_plus <plus_n_Sm <plus_n_O @eq_f
- @(div_mod_spec_to_eq n1 q (div n1 q) (mod n1 q) ? (mod n1 q))
- [@div_mod_spec_div_mod //
- |@div_mod_spec_intro [@lt_mod_m_m // | //]
- ]
- |%
- ]
- |@true_to_andb_true [//|@divides_to_dividesb_true //]
- ]
- |* #ndiv #eqn1 >bigop_Sfalse
- [>(mod_S … posq)
- [< plus_n_Sm @eq_f //
- |cases (le_to_or_lt_eq (S (mod n1 q)) q ?)
- [//
- |#eqq @False_ind cases ndiv #Hdiv @Hdiv
- %{(S(div n1 q))} <times_n_Sm <commutative_plus //
- |@lt_mod_m_m //
- ]
- ]
- |>not_divides_to_dividesb_false //
- ]
- ]
- ]
- ]
- |@div_mod_spec_div_mod //
- ]
-qed.
-
-lemma timesACdef: ∀n,m. timesAC n m = n * m.
-// qed-.
-
-(* still another characterization of the factorial *)
-theorem fact_pi_p: ∀n.
-fact n = ∏_{ p < S n | primeb p}
- (∏_{i < log p n} (exp p (n /(exp p (S i))))).
-#n >eq_fact_pi_p
-@(trans_eq ??
- (∏_{m < S n | leb 1 m}
- (∏_{p < S m | primeb p}
- (∏_{i < log p m | dividesb (exp p (S i)) m} p))))
- [@same_bigop [// |#x #Hx1 #Hx2 @pi_p_primeb1 @leb_true_to_le //]
- |@(trans_eq ??
- (∏_{m < S n | leb 1 m}
- (∏_{p < S m | primeb p ∧ leb p m}
- (∏_{ i < log p m | dividesb ((p)\sup(S i)) m} p))))
- [@same_bigop
- [//
- |#x #Hx1 #Hx2 @same_bigop
- [#p #ltp >(le_to_leb_true … (le_S_S_to_le …ltp))
- cases (primeb p) //
- |//
- ]
- ]
- |@(trans_eq ??
- (∏_{m < S n | leb 1 m}
- (∏_{p < S n | primeb p ∧ leb p m}
- (∏_{i < log p m |dividesb ((p)\sup(S i)) m} p))))
- [@same_bigop
- [//
- |#p #Hp1 #Hp2 @pad_bigop1
- [@Hp1
- |#i #lti #upi >lt_to_leb_false
- [cases (primeb i) //|@lti]
- ]
- ]
- |(* make a general theorem *)
- @(trans_eq ??
- (∏_{p < S n | primeb p}
- (∏_{m < S n | leb p m}
- (∏_{i < log p m | dividesb (p^(S i)) m} p))))
- [@(bigop_commute … timesAC … (lt_O_S n) (lt_O_S n))
- #i #j #lti #ltj
- cases (true_or_false (primeb j ∧ leb j i)) #Hc >Hc
- [>(le_to_leb_true 1 i)
- [//
- |@(transitive_le ? j)
- [@prime_to_lt_O @primeb_true_to_prime @(andb_true_l ? ? Hc)
- |@leb_true_to_le @(andb_true_r ?? Hc)
- ]
- ]
- |cases(leb 1 i) //
- ]
- |@same_bigop
- [//
- |#p #Hp1 #Hp2
- @(trans_eq ??
- (∏_{m < S n | leb p m}
- (∏_{i < log p n | dividesb (p\sup(S i)) m} p)))
- [@same_bigop
- [//
- |#x #Hx1 #Hx2 @sym_eq
- @sym_eq @pad_bigop1
- [@le_log
- [@prime_to_lt_SO @primeb_true_to_prime //
- |@le_S_S_to_le //
- ]
- |#i #Hi1 #Hi2 @not_divides_to_dividesb_false
- [@lt_O_exp @prime_to_lt_O @primeb_true_to_prime //
- |@(not_to_not … (lt_to_not_le x (exp p (S i)) ?))
- [#H @divides_to_le // @(lt_to_le_to_lt ? p)
- [@prime_to_lt_O @primeb_true_to_prime //
- |@leb_true_to_le //
- ]
- |@(lt_to_le_to_lt ? (exp p (S(log p x))))
- [@lt_exp_log @prime_to_lt_SO @primeb_true_to_prime //
- |@le_exp
- [@ prime_to_lt_O @primeb_true_to_prime //
- |@le_S_S //
- ]
- ]
- ]
- ]
- ]
- ]
- |@
- (trans_eq ? ?
- (∏_{i < log p n}
- (∏_{m < S n | leb p m ∧ dividesb (p\sup(S i)) m} p)))
- [@(bigop_commute ?????? nat 1 timesAC (λm,i.p) ???) //
- cut (p ≤ n) [@le_S_S_to_le //] #lepn
- @(lt_O_log … lepn) @(lt_to_le_to_lt … lepn) @prime_to_lt_SO
- @primeb_true_to_prime //
- |@same_bigop
- [//
- |#m #ltm #_ >exp_sigma @eq_f
- @(trans_eq ??
- (∑_{i < S n |leb 1 i∧dividesb (p\sup(S m)) i} 1))
- [@same_bigop
- [#i #lti
- cases (true_or_false (dividesb (p\sup(S m)) i)) #Hc >Hc
- [cases (true_or_false (leb p i)) #Hp3 >Hp3
- [>le_to_leb_true
- [//
- |@(transitive_le ? p)
- [@prime_to_lt_O @primeb_true_to_prime //
- |@leb_true_to_le //
- ]
- ]
- |>lt_to_leb_false
- [//
- |@not_le_to_lt
- @(not_to_not ??? (leb_false_to_not_le ?? Hp3)) #posi
- @(transitive_le ? (exp p (S m)))
- [>(exp_n_1 p) in ⊢ (?%?);
- @le_exp
- [@prime_to_lt_O @primeb_true_to_prime //
- |@le_S_S @le_O_n
- ]
- |@(divides_to_le … posi)
- @dividesb_true_to_divides //
- ]
- ]
- ]
- |cases (leb p i) cases (leb 1 i) //
- ]
- |//
- ]
- |@eq_sigma_p_div @lt_O_exp
- @prime_to_lt_O @primeb_true_to_prime //
- ]
- ]
- ]
- ]
- ]
- ]
- ]
- ]
- ]
-qed.
-
-theorem fact_pi_p2: ∀n. fact (2*n) =
-∏_{p < S (2*n) | primeb p}
- (∏_{i < log p (2*n)}
- (exp p (2*(n /(exp p (S i))))*(exp p (mod (2*n /(exp p (S i))) 2)))).
-#n >fact_pi_p @same_bigop
- [//
- |#p #ltp #primep @same_bigop
- [//
- |#i #lti #_ <exp_plus_times @eq_f
- >commutative_times in ⊢ (???(?%?));
- cut (0 < p ^ (S i))
- [@lt_O_exp @prime_to_lt_O @primeb_true_to_prime //]
- generalize in match (p ^(S i)); #a #posa
- >(div_times_times n a 2) // >(commutative_times n 2)
- <eq_div_div_div_times //
- ]
- ]
-qed.
-
-theorem fact_pi_p3: ∀n. fact (2*n) =
-∏_{p < S (2*n) | primeb p}
- (∏_{i < log p (2*n)}(exp p (2*(n /(exp p (S i)))))) *
-∏_{p < S (2*n) | primeb p}
- (∏_{i < log p (2*n)}(exp p (mod (2*n /(exp p (S i))) 2))).
-#n <times_pi >fact_pi_p2 @same_bigop
- [//
- |#p #ltp #primep @times_pi
- ]
-qed.
-
-theorem pi_p_primeb4: ∀n. 1 < n →
-∏_{p < S (2*n) | primeb p}
- (∏_{i < log p (2*n)}(exp p (2*(n /(exp p (S i))))))
-=
-∏_{p < S n | primeb p}
- (∏_{i < log p (2*n)}(exp p (2*(n /(exp p (S i)))))).
-#n #lt1n
-@sym_eq @(pad_bigop_nil … timesAC)
- [@le_S_S /2 by /
- |#i #ltn #lti %2
- >log_i_2n //
- [>bigop_Strue // whd in ⊢ (??(??%)?); <times_n_1
- <exp_n_1 >eq_div_O //
- |@le_S_S_to_le //
- ]
- ]
-qed.
-
-theorem pi_p_primeb5: ∀n. 1 < n →
-∏_{p < S (2*n) | primeb p}
- (∏_{i < log p (2*n)} (exp p (2*(n /(exp p (S i))))))
-=
-∏_{p < S n | primeb p}
- (∏_{i < log p n} (exp p (2*(n /(exp p (S i)))))).
-#n #lt1n >(pi_p_primeb4 ? lt1n) @same_bigop
- [//
- |#p #lepn #primebp @sym_eq @(pad_bigop_nil … timesAC)
- [@le_log
- [@prime_to_lt_SO @primeb_true_to_prime //
- |//
- ]
- |#i #lelog #lti %2 >eq_div_O //
- @(lt_to_le_to_lt ? (exp p (S(log p n))))
- [@lt_exp_log @prime_to_lt_SO @primeb_true_to_prime //
- |@le_exp
- [@prime_to_lt_O @primeb_true_to_prime // |@le_S_S //]
- ]
- ]
- ]
-qed.
-
-theorem exp_fact_2: ∀n.
-exp (fact n) 2 =
- ∏_{p < S n| primeb p}
- (∏_{i < log p n} (exp p (2*(n /(exp p (S i)))))).
-#n >fact_pi_p <exp_pi @same_bigop
- [//
- |#p #ltp #primebp @sym_eq
- @(trans_eq ?? (∏_{x < log p n} (exp (exp p (n/(exp p (S x)))) 2)))
- [@same_bigop
- [//
- |#x #ltx #_ @sym_eq >commutative_times @exp_exp_times
- ]
- |@exp_pi
- ]
-qed.
-
+++ /dev/null
-(*
- ||M|| This file is part of HELM, an Hypertextual, Electronic
- ||A|| Library of Mathematics, developed at the Computer Science
- ||T|| Department of the University of Bologna, Italy.
- ||I||
- ||T||
- ||A|| This file is distributed under the terms of the
- \ / GNU General Public License Version 2
- \ /
- V_______________________________________________________________ *)
-
-include "arithmetics/binomial.ma".
-include "arithmetics/gcd.ma".
-include "arithmetics/chebyshev/chebyshev_psi.ma".
-
-(* This is chebishev theta function *)
-
-definition theta: nat → nat ≝ λn.
- ∏_{p < S n| primeb p} p.
-
-lemma theta_def: ∀n.theta n = ∏_{p < S n| primeb p} p.
-// qed.
-
-theorem lt_O_theta: ∀n. O < theta n.
-#n elim n
- [@le_n
- |#n1 #Hind cases (true_or_false (primeb (S n1))) #Hc
- [>theta_def >bigop_Strue
- [>(times_n_O O) @lt_times // | //]
- |>theta_def >bigop_Sfalse //
- ]
- ]
-qed.
-
-theorem divides_fact_to_divides: ∀p,n. prime p → divides p n! →
- ∃m.O < m ∧ m \le n ∧ divides p m.
-#p #n #primep elim n
- [normalize in ⊢ (%→?); #H @False_ind @(absurd (p ≤1))
- [@divides_to_le //|@lt_to_not_le @prime_to_lt_SO @primep]
- |#n1 #Hind >factS #Hdiv
- cases (divides_times_to_divides ??? primep Hdiv) #Hcase
- [%{(S n1)} %[ % [@lt_O_S |@le_n] |@Hcase]
- |cases(Hind Hcase) #a * * #posa #lea #diva
- %{a} % [% [// |@le_S //] |//]
- ]
- ]
-qed.
-
-theorem divides_fact_to_le: ∀p,n. prime p → divides p n! → p ≤ n.
-#p #n #primep #divp cases (divides_fact_to_divides p n primep divp)
-#a * * #posa #lea #diva @(transitive_le ? a) [@divides_to_le // | //]
-qed.
-
-theorem prime_to_divides_M: ∀m,p.
- prime p → S m < p → p ≤ S(2*m) → divides p (M m).
-#m #p #primep #lemp #lep >Mdef >bceq
-cases (bc2 (S(2*m)) m ?)
- [#q #Hq >Hq >commutative_times >div_times
- [cases (divides_times_to_divides p (m!*(S (2*m)-m)!) q primep ?)
- [#Hdiv @False_ind
- cases (divides_times_to_divides p (m!) (S (2*m)-m)! primep ?)
- [-Hdiv #Hdiv @(absurd (p ≤ m))
- [@divides_fact_to_le //
- |@(lt_to_not_le ?? (lt_to_le ?? lemp))
- ]
- |-Hdiv #Hdiv @(absurd (p ≤S m))
- [@(divides_fact_to_le … primep)
- cut (S m = S(2*m)-m)
- [normalize in ⊢ (???(?%?)); <plus_n_O
- >plus_n_Sm >commutative_plus @minus_plus_m_m
- ] #HSm
- >HSm //
- |@lt_to_not_le //
- ]
- |//
- ]
- |//
- |<Hq @divides_fact [@prime_to_lt_O // |//]
- ]
- |>(times_n_O O) in ⊢ (?%?); @lt_times //
- ]
- |normalize in ⊢ (??(?%)); <plus_n_O //
- ]
-qed.
-
-theorem divides_pi_p_M1: ∀m.∀i. i ≤ S(S(2*m)) →
- ∏_{p < i | leb (S(S m)) p ∧ primeb p} p ∣ M m .
-#m #i elim i
- [#_ @(quotient ?? (M m)) >commutative_times @times_n_1
- |#n #Hind #len
- cases (true_or_false (leb (S (S m)) n ∧ primeb n)) #Hc
- [>bigop_Strue
- [@divides_to_divides_times
- [@primeb_true_to_prime @(andb_true_r ?? Hc)
- |cut (∀p.prime p → n ≤ p → ¬p∣∏_{p < n | leb (S (S m)) p∧primeb p} p)
- [2: #Hcut @(Hcut … (le_n ?)) @primeb_true_to_prime @(andb_true_r ?? Hc)]
- #p #primep elim n
- [#_ normalize @(not_to_not ? (p ≤ 1))
- [@divides_to_le @lt_O_S|@lt_to_not_le @prime_to_lt_SO //]
- |#n1 #Hind1 #Hn1 cases (true_or_false (leb (S (S m)) n1∧primeb n1)) #Hc1
- [>bigop_Strue
- [% #Habs cases(divides_times_to_divides ??? primep Habs)
- [-Habs #Habs @(absurd … Hn1) @le_to_not_lt
- @(divides_to_le … Habs) @prime_to_lt_O
- @primeb_true_to_prime @(andb_true_r ?? Hc1)
- |-Habs #Habs @(absurd … Habs) @Hind1 @lt_to_le //
- ]
- |@Hc1
- ]
- |>bigop_Sfalse // @Hind1 @lt_to_le //
- ]
- ]
- |@prime_to_divides_M
- [@primeb_true_to_prime @(andb_true_r ?? Hc)
- |@leb_true_to_le @(andb_true_l ?? Hc)
- |@le_S_S_to_le //
- ]
- |@Hind @lt_to_le //
- ]
- |@Hc
- ]
- |>bigop_Sfalse // @Hind @lt_to_le @len
- ]
- ]
-qed.
-
-theorem divides_pi_p_M:∀m.
- ∏_{p < S(S(2*m)) | leb (S(S m)) p ∧ primeb p} p ∣ (M m).
-#m @divides_pi_p_M1 @le_n
-qed.
-
-theorem theta_pi_p_theta: ∀m. theta (S (2*m))
-= (∏_{p < S (S (2*m)) | leb (S (S m)) p∧primeb p} p)*theta (S m).
-#m >theta_def >theta_def
-<(bigop_I ???? timesA)
->(bigop_sumI 0 (S(S m)) (S(S(2*m))) (λp.primeb p) … timesA (λp.p))
- [2:@le_S_S @le_S_S // |3:@le_O_n]
-@eq_f2
- [>bigop_I_gen // |@(bigop_I … timesA)]
-qed.
-
-theorem div_theta_theta: ∀m.
- theta (S(2*m))/theta (S m) =
- ∏_{p < S(S(2*m)) | leb (S(S m)) p ∧ primeb p} p.
-#m @(div_mod_spec_to_eq ????? 0 (div_mod_spec_div_mod …))
- [@lt_O_theta
- |@div_mod_spec_intro [@lt_O_theta |<plus_n_O @theta_pi_p_theta]
- ]
-qed.
-
-theorem le_theta_M_theta: ∀m.
- theta (S(2*m)) ≤ (M m)*theta (S m).
-#m >theta_pi_p_theta @le_times [2://] @divides_to_le
- [@lt_O_bc @lt_to_le @le_S_S // | @divides_pi_p_M
- ]
-qed.
-
-theorem lt_O_to_le_theta_exp_theta: ∀m. O < m→
- theta (S(2*m)) < exp 2 (2*m)*theta (S m).
-#m #posm @(le_to_lt_to_lt ? (M m*theta (S m)))
- [@le_theta_M_theta
- |@monotonic_lt_times_l [@lt_O_theta|@lt_M //]
- ]
-qed.
-
-theorem theta_pred: ∀n. 1 < n → theta (2*n) = theta (pred (2*n)).
-#n #lt1n >theta_def >theta_def >bigop_Sfalse
- [>S_pred
- [//
- |>(times_n_O 2) in ⊢ (?%?); @monotonic_lt_times_r @lt_to_le //
- ]
- |@not_prime_to_primeb_false % * #lt2n #Hprime
- @(absurd (2=2*n))
- [@(Hprime … (le_n ?)) %{n} //
- |@lt_to_not_eq >(times_n_1 2) in ⊢ (?%?); @monotonic_lt_times_r //
- ]
- ]
-qed.
-
-theorem le_theta: ∀m.theta m ≤ exp 2 (2*m).
-#m @(nat_elim1 m) #m1 #Hind
-cut (∀a. 2 *a = a+a) [//] #times2
-cases (even_or_odd m1) #a * #Ha >Ha
- [lapply Ha cases a
- [#_ @le_n
- |#n cases n
- [#_ @leb_true_to_le //
- |#n1 #Hn1 >theta_pred
- [cut (pred (2*S(S n1)) = (S (2*S n1)))
- [normalize >plus_n_Sm in ⊢ (???%); //] #Hcut >Hcut
- @(transitive_le ? (exp 2 (2*(S n1))*theta (S (S n1))))
- [@lt_to_le @lt_O_to_le_theta_exp_theta @lt_O_S
- |>times2 in ⊢ (??%);>exp_plus_times in ⊢ (??%); @le_times
- [@le_exp [@lt_O_S |@monotonic_le_times_r @le_n_Sn]
- |@Hind >Hn1 >times2 //
- ]
- ]
- |@le_S_S @lt_O_S
- ]
- ]
- ]
- |lapply Ha cases a
- [#_ @leb_true_to_le //
- |#n #Hn @(transitive_le ? (exp 2 (2*(S n))*theta (S (S n))))
- [@lt_to_le @lt_O_to_le_theta_exp_theta @lt_O_S
- |>times2 in ⊢ (??%); <plus_n_Sm <commutative_plus >plus_n_Sm
- >exp_plus_times in ⊢ (??%); @monotonic_le_times_r
- cut (∀a. 2*(S a) = S(S(2*a))) [#a normalize <plus_n_Sm //] #timesSS
- <timesSS @Hind >Hn @le_S_S >times2 //
- ]
- ]
- ]
-qed.
-