X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fbroken_lib%2Freverse_complexity%2Fspeed_def.ma;fp=matita%2Fmatita%2Fbroken_lib%2Freverse_complexity%2Fspeed_def.ma;h=0000000000000000000000000000000000000000;hb=b8e8c61042dd7d4d8bc00971e1ebcd6858064682;hp=9812cfb08673852fa2f7736c6ead07857a9d95dc;hpb=990530d17001326448884ea9bdd0d756af9280d9;p=helm.git diff --git a/matita/matita/broken_lib/reverse_complexity/speed_def.ma b/matita/matita/broken_lib/reverse_complexity/speed_def.ma deleted file mode 100644 index 9812cfb08..000000000 --- a/matita/matita/broken_lib/reverse_complexity/speed_def.ma +++ /dev/null @@ -1,922 +0,0 @@ -include "basics/types.ma". -include "arithmetics/minimization.ma". -include "arithmetics/bigops.ma". -include "arithmetics/sigma_pi.ma". -include "arithmetics/bounded_quantifiers.ma". -include "reverse_complexity/big_O.ma". -include "basics/core_notation/napart_2.ma". - -(************************* notation for minimization *****************************) -notation "μ_{ ident i < n } p" - with precedence 80 for @{min $n 0 (λ${ident i}.$p)}. - -notation "μ_{ ident i ≤ n } p" - with precedence 80 for @{min (S $n) 0 (λ${ident i}.$p)}. - -notation "μ_{ ident i ∈ [a,b[ } p" - with precedence 80 for @{min ($b-$a) $a (λ${ident i}.$p)}. - -notation "μ_{ ident i ∈ [a,b] } p" - with precedence 80 for @{min (S $b-$a) $a (λ${ident i}.$p)}. - -(************************************ MAX *************************************) -notation "Max_{ ident i < n | p } f" - with precedence 80 -for @{'bigop $n max 0 (λ${ident i}. $p) (λ${ident i}. $f)}. - -notation "Max_{ ident i < n } f" - with precedence 80 -for @{'bigop $n max 0 (λ${ident i}.true) (λ${ident i}. $f)}. - -notation "Max_{ ident j ∈ [a,b[ } f" - with precedence 80 -for @{'bigop ($b-$a) max 0 (λ${ident j}.((λ${ident j}.true) (${ident j}+$a))) - (λ${ident j}.((λ${ident j}.$f)(${ident j}+$a)))}. - -notation "Max_{ ident j ∈ [a,b[ | p } f" - with precedence 80 -for @{'bigop ($b-$a) max 0 (λ${ident j}.((λ${ident j}.$p) (${ident j}+$a))) - (λ${ident j}.((λ${ident j}.$f)(${ident j}+$a)))}. - -lemma Max_assoc: ∀a,b,c. max (max a b) c = max a (max b c). -#a #b #c normalize cases (true_or_false (leb a b)) #leab >leab normalize - [cases (true_or_false (leb b c )) #lebc >lebc normalize - [>(le_to_leb_true a c) // @(transitive_le ? b) @leb_true_to_le // - |>leab // - ] - |cases (true_or_false (leb b c )) #lebc >lebc normalize // - >leab normalize >(not_le_to_leb_false a c) // @lt_to_not_le - @(transitive_lt ? b) @not_le_to_lt @leb_false_to_not_le // - ] -qed. - -lemma Max0 : ∀n. max 0 n = n. -// qed. - -lemma Max0r : ∀n. max n 0 = n. -#n >commutative_max // -qed. - -definition MaxA ≝ - mk_Aop nat 0 max Max0 Max0r (λa,b,c.sym_eq … (Max_assoc a b c)). - -definition MaxAC ≝ mk_ACop nat 0 MaxA commutative_max. - -lemma le_Max: ∀f,p,n,a. a < n → p a = true → - f a ≤ Max_{i < n | p i}(f i). -#f #p #n #a #ltan #pa ->(bigop_diff p ? 0 MaxAC f a n) // @(le_maxl … (le_n ?)) -qed. - -lemma le_MaxI: ∀f,p,n,m,a. m ≤ a → a < n → p a = true → - f a ≤ Max_{i ∈ [m,n[ | p i}(f i). -#f #p #n #m #a #lema #ltan #pa ->(bigop_diff ? ? 0 MaxAC (λi.f (i+m)) (a-m) (n-m)) - [bigop_Strue [2:@Hb] @to_max [@H1 // | @H #a #ltab #pa @H1 // @le_S //] - |>bigop_Sfalse [2:@Hb] @H #a #ltab #pa @H1 // @le_S // - ] -qed. - -(********************************** pairing ***********************************) -axiom pair: nat → nat → nat. -axiom fst : nat → nat. -axiom snd : nat → nat. - -interpretation "abstract pair" 'pair f g = (pair f g). - -axiom fst_pair: ∀a,b. fst 〈a,b〉 = a. -axiom snd_pair: ∀a,b. snd 〈a,b〉 = b. -axiom surj_pair: ∀x. ∃a,b. x = 〈a,b〉. - -axiom le_fst : ∀p. fst p ≤ p. -axiom le_snd : ∀p. snd p ≤ p. -axiom le_pair: ∀a,a1,b,b1. a ≤ a1 → b ≤ b1 → 〈a,b〉 ≤ 〈a1,b1〉. - -(************************************* U **************************************) -axiom U: nat → nat →nat → option nat. - -axiom monotonic_U: ∀i,x,n,m,y.n ≤m → - U i x n = Some ? y → U i x m = Some ? y. - -lemma unique_U: ∀i,x,n,m,yn,ym. - U i x n = Some ? yn → U i x m = Some ? ym → yn = ym. -#i #x #n #m #yn #ym #Hn #Hm cases (decidable_le n m) - [#lenm lapply (monotonic_U … lenm Hn) >Hm #HS destruct (HS) // - |#ltmn lapply (monotonic_U … n … Hm) [@lt_to_le @not_le_to_lt //] - >Hn #HS destruct (HS) // - ] -qed. - -definition code_for ≝ λf,i.∀x. - ∃n.∀m. n ≤ m → U i x m = f x. - -definition terminate ≝ λi,x,r. ∃y. U i x r = Some ? y. - -notation "{i ⊙ x} ↓ r" with precedence 60 for @{terminate $i $x $r}. - -lemma terminate_dec: ∀i,x,n. {i ⊙ x} ↓ n ∨ ¬ {i ⊙ x} ↓ n. -#i #x #n normalize cases (U i x n) - [%2 % * #y #H destruct|#y %1 %{y} //] -qed. - -lemma monotonic_terminate: ∀i,x,n,m. - n ≤ m → {i ⊙ x} ↓ n → {i ⊙ x} ↓ m. -#i #x #n #m #lenm * #z #H %{z} @(monotonic_U … H) // -qed. - -definition termb ≝ λi,x,t. - match U i x t with [None ⇒ false |Some y ⇒ true]. - -lemma termb_true_to_term: ∀i,x,t. termb i x t = true → {i ⊙ x} ↓ t. -#i #x #t normalize cases (U i x t) normalize [#H destruct | #y #_ %{y} //] -qed. - -lemma term_to_termb_true: ∀i,x,t. {i ⊙ x} ↓ t → termb i x t = true. -#i #x #t * #y #H normalize >H // -qed. - -definition out ≝ λi,x,r. - match U i x r with [ None ⇒ 0 | Some z ⇒ z]. - -definition bool_to_nat: bool → nat ≝ - λb. match b with [true ⇒ 1 | false ⇒ 0]. - -coercion bool_to_nat. - -definition pU : nat → nat → nat → nat ≝ λi,x,r.〈termb i x r,out i x r〉. - -lemma pU_vs_U_Some : ∀i,x,r,y. pU i x r = 〈1,y〉 ↔ U i x r = Some ? y. -#i #x #r #y % normalize - [cases (U i x r) normalize - [#H cut (0=1) [lapply (eq_f … fst … H) >fst_pair >fst_pair #H @H] - #H1 destruct - |#a #H cut (a=y) [lapply (eq_f … snd … H) >snd_pair >snd_pair #H1 @H1] - #H1 // - ] - |#H >H //] -qed. - -lemma pU_vs_U_None : ∀i,x,r. pU i x r = 〈0,0〉 ↔ U i x r = None ?. -#i #x #r % normalize - [cases (U i x r) normalize // - #a #H cut (1=0) [lapply (eq_f … fst … H) >fst_pair >fst_pair #H1 @H1] - #H1 destruct - |#H >H //] -qed. - -lemma fst_pU: ∀i,x,r. fst (pU i x r) = termb i x r. -#i #x #r normalize cases (U i x r) normalize >fst_pair // -qed. - -lemma snd_pU: ∀i,x,r. snd (pU i x r) = out i x r. -#i #x #r normalize cases (U i x r) normalize >snd_pair // -qed. - -(********************************* the speedup ********************************) - -definition min_input ≝ λh,i,x. μ_{y ∈ [S i,x] } (termb i y (h (S i) y)). - -lemma min_input_def : ∀h,i,x. - min_input h i x = min (x -i) (S i) (λy.termb i y (h (S i) y)). -// qed. - -lemma min_input_i: ∀h,i,x. x ≤ i → min_input h i x = S i. -#h #i #x #lexi >min_input_def -cut (x - i = 0) [@sym_eq /2 by eq_minus_O/] #Hcut // -qed. - -lemma min_input_to_terminate: ∀h,i,x. - min_input h i x = x → {i ⊙ x} ↓ (h (S i) x). -#h #i #x #Hminx -cases (decidable_le (S i) x) #Hix - [cases (true_or_false (termb i x (h (S i) x))) #Hcase - [@termb_true_to_term // - |min_input_def in Hminx; #Hminx >Hminx in ⊢ (%→?); - min_input_i in Hminx; - [#eqix >eqix in Hix; * /2/ | @le_S_S_to_le @not_le_to_lt //] - ] -qed. - -lemma min_input_to_lt: ∀h,i,x. - min_input h i x = x → i < x. -#h #i #x #Hminx cases (decidable_le (S i) x) // -#ltxi @False_ind >min_input_i in Hminx; - [#eqix >eqix in ltxi; * /2/ | @le_S_S_to_le @not_le_to_lt //] -qed. - -lemma le_to_min_input: ∀h,i,x,x1. x ≤ x1 → - min_input h i x = x → min_input h i x1 = x. -#h #i #x #x1 #lex #Hminx @(min_exists … (le_S_S … lex)) - [@(fmin_true … (sym_eq … Hminx)) // - |@(min_input_to_lt … Hminx) - |#j #H1 g_def cut (x-u = 0) [/2 by minus_le_minus_minus_comm/] -#eq0 >eq0 normalize // qed. - -lemma g_lt : ∀h,i,x. min_input h i x = x → - out i x (h (S i) x) < g h 0 x. -#h #i #x #H @le_S_S @(le_MaxI … i) /2 by min_input_to_lt/ -qed. - -lemma max_neq0 : ∀a,b. max a b ≠ 0 → a ≠ 0 ∨ b ≠ 0. -#a #b whd in match (max a b); cases (true_or_false (leb a b)) #Hcase >Hcase - [#H %2 @H | #H %1 @H] -qed. - -definition almost_equal ≝ λf,g:nat → nat. ¬ ∀nu.∃x. nu < x ∧ f x ≠ g x. -interpretation "almost equal" 'napart f g = (almost_equal f g). - -lemma eventually_cancelled: ∀h,u.¬∀nu.∃x. nu < x ∧ - max_{i ∈ [0,u[ | eqb (min_input h i x) x} (out i x (h (S i) x)) ≠ 0. -#h #u elim u - [normalize % #H cases (H u) #x * #_ * #H1 @H1 // - |#u0 @not_to_not #Hind #nu cases (Hind nu) #x * #ltx - cases (true_or_false (eqb (min_input h (u0+O) x) x)) #Hcase - [>bigop_Strue [2:@Hcase] #Hmax cases (max_neq0 … Hmax) -Hmax - [2: #H %{x} % // bigop_Sfalse - [#H %{x1} % [@transitive_lt //| (le_to_min_input … (eqb_true_to_eq … Hcase)) - [@lt_to_not_eq @ltx1 | @lt_to_le @ltx1] - ] - |>bigop_Sfalse [2:@Hcase] #H %{x} % // (bigop_sumI 0 u x (λi:ℕ.eqb (min_input h i x) x) nat 0 MaxA) - [>H // |@lt_to_le @(le_to_lt_to_lt …ltx) /2 by le_maxr/ |//] -qed. - -(******************************** Condition 2 *********************************) -definition total ≝ λf.λx:nat. Some nat (f x). - -lemma exists_to_exists_min: ∀h,i. (∃x. i < x ∧ {i ⊙ x} ↓ h (S i) x) → ∃y. min_input h i y = y. -#h #i * #x * #ltix #Hx %{(min_input h i x)} @min_spec_to_min @found // - [@(f_min_true (λy:ℕ.termb i y (h (S i) y))) %{x} % [% // | @term_to_termb_true //] - |#y #leiy #lty @(lt_min_to_false ????? lty) // - ] -qed. - -lemma condition_2: ∀h,i. code_for (total (g h 0)) i → ¬∃x. itermy >Hr -#H @(absurd ? H) @le_to_not_lt @le_n -qed. - - -(********************************* complexity *********************************) - -(* We assume operations have a minimal structural complexity MSC. -For instance, for time complexity, MSC is equal to the size of input. -For space complexity, MSC is typically 0, since we only measure the -space required in addition to dimension of the input. *) - -axiom MSC : nat → nat. -axiom MSC_le: ∀n. MSC n ≤ n. -axiom monotonic_MSC: monotonic ? le MSC. -axiom MSC_pair: ∀a,b. MSC 〈a,b〉 ≤ MSC a + MSC b. - -(* C s i means i is running in O(s) *) - -definition C ≝ λs,i.∃c.∃a.∀x.a ≤ x → ∃y. - U i x (c*(s x)) = Some ? y. - -(* C f s means f ∈ O(s) where MSC ∈O(s) *) -definition CF ≝ λs,f.O s MSC ∧ ∃i.code_for (total f) i ∧ C s i. - -lemma ext_CF : ∀f,g,s. (∀n. f n = g n) → CF s f → CF s g. -#f #g #s #Hext * #HO * #i * #Hcode #HC % // %{i} % - [#x cases (Hcode x) #a #H %{a} whd in match (total ??); associative_times @le_times // @Ha1 @(transitive_le … lean) // - ] -qed. - -lemma timesc_CF: ∀s,f,c.CF (λx.c*s x) f → CF s f. -#s #f #c @O_to_CF @O_times_c -qed. - -(********************************* composition ********************************) -axiom CF_comp: ∀f,g,sf,sg,sh. CF sg g → CF sf f → - O sh (λx. sg x + sf (g x)) → CF sh (f ∘ g). - -lemma CF_comp_ext: ∀f,g,h,sh,sf,sg. CF sg g → CF sf f → - (∀x.f(g x) = h x) → O sh (λx. sg x + sf (g x)) → CF sh h. -#f #g #h #sh #sf #sg #Hg #Hf #Heq #H @(ext_CF (f ∘ g)) - [#n normalize @Heq | @(CF_comp … H) //] -qed. - - -(**************************** primitive operations*****************************) - -definition id ≝ λx:nat.x. - -axiom CF_id: CF MSC id. -axiom CF_compS: ∀h,f. CF h f → CF h (S ∘ f). -axiom CF_comp_fst: ∀h,f. CF h f → CF h (fst ∘ f). -axiom CF_comp_snd: ∀h,f. CF h f → CF h (snd ∘ f). -axiom CF_comp_pair: ∀h,f,g. CF h f → CF h g → CF h (λx. 〈f x,g x〉). - -lemma CF_fst: CF MSC fst. -@(ext_CF (fst ∘ id)) [#n //] @(CF_comp_fst … CF_id) -qed. - -lemma CF_snd: CF MSC snd. -@(ext_CF (snd ∘ id)) [#n //] @(CF_comp_snd … CF_id) -qed. - -(************************************** eqb ***********************************) - -axiom CF_eqb: ∀h,f,g. - CF h f → CF h g → CF h (λx.eqb (f x) (g x)). - -(*********************************** maximum **********************************) - -axiom CF_max: ∀a,b.∀p:nat →bool.∀f,ha,hb,hp,hf,s. - CF ha a → CF hb b → CF hp p → CF hf f → - O s (λx.ha x + hb x + ∑_{i ∈[a x ,b x[ }(hp 〈i,x〉 + hf 〈i,x〉)) → - CF s (λx.max_{i ∈[a x,b x[ | p 〈i,x〉 }(f 〈i,x〉)). - -(******************************** minimization ********************************) - -axiom CF_mu: ∀a,b.∀f:nat →bool.∀sa,sb,sf,s. - CF sa a → CF sb b → CF sf f → - O s (λx.sa x + sb x + ∑_{i ∈[a x ,S(b x)[ }(sf 〈i,x〉)) → - CF s (λx.μ_{i ∈[a x,b x] }(f 〈i,x〉)). - -(************************************* smn ************************************) -axiom smn: ∀f,s. CF s f → ∀x. CF (λy.s 〈x,y〉) (λy.f 〈x,y〉). - -(****************************** constructibility ******************************) - -definition constructible ≝ λs. CF s s. - -lemma constr_comp : ∀s1,s2. constructible s1 → constructible s2 → - (∀x. x ≤ s2 x) → constructible (s2 ∘ s1). -#s1 #s2 #Hs1 #Hs2 #Hle @(CF_comp … Hs1 Hs2) @O_plus @le_to_O #x [@Hle | //] -qed. - -lemma ext_constr: ∀s1,s2. (∀x.s1 x = s2 x) → - constructible s1 → constructible s2. -#s1 #s2 #Hext #Hs1 @(ext_CF … Hext) @(monotonic_CF … Hs1) #x >Hext // -qed. - -(********************************* simulation *********************************) - -axiom sU : nat → nat. - -axiom monotonic_sU: ∀i1,i2,x1,x2,s1,s2. i1 ≤ i2 → x1 ≤ x2 → s1 ≤ s2 → - sU 〈i1,〈x1,s1〉〉 ≤ sU 〈i2,〈x2,s2〉〉. - -lemma monotonic_sU_aux : ∀x1,x2. fst x1 ≤ fst x2 → fst (snd x1) ≤ fst (snd x2) → -snd (snd x1) ≤ snd (snd x2) → sU x1 ≤ sU x2. -#x1 #x2 cases (surj_pair x1) #a1 * #y #eqx1 >eqx1 -eqx1 cases (surj_pair y) -#b1 * #c1 #eqy >eqy -eqy -cases (surj_pair x2) #a2 * #y2 #eqx2 >eqx2 -eqx2 cases (surj_pair y2) -#b2 * #c2 #eqy2 >eqy2 -eqy2 >fst_pair >snd_pair >fst_pair >snd_pair ->fst_pair >snd_pair >fst_pair >snd_pair @monotonic_sU -qed. - -axiom sU_le: ∀i,x,s. s ≤ sU 〈i,〈x,s〉〉. -axiom sU_le_i: ∀i,x,s. MSC i ≤ sU 〈i,〈x,s〉〉. -axiom sU_le_x: ∀i,x,s. MSC x ≤ sU 〈i,〈x,s〉〉. - -definition pU_unary ≝ λp. pU (fst p) (fst (snd p)) (snd (snd p)). - -axiom CF_U : CF sU pU_unary. - -definition termb_unary ≝ λx:ℕ.termb (fst x) (fst (snd x)) (snd (snd x)). -definition out_unary ≝ λx:ℕ.out (fst x) (fst (snd x)) (snd (snd x)). - -lemma CF_termb: CF sU termb_unary. -@(ext_CF (fst ∘ pU_unary)) [2: @CF_comp_fst @CF_U] -#n whd in ⊢ (??%?); whd in ⊢ (??(?%)?); >fst_pair % -qed. - -lemma CF_out: CF sU out_unary. -@(ext_CF (snd ∘ pU_unary)) [2: @CF_comp_snd @CF_U] -#n whd in ⊢ (??%?); whd in ⊢ (??(?%)?); >snd_pair % -qed. - - -(******************** complexity of g ********************) - -definition unary_g ≝ λh.λux. g h (fst ux) (snd ux). -definition auxg ≝ - λh,ux. max_{i ∈[fst ux,snd ux[ | eqb (min_input h i (snd ux)) (snd ux)} - (out i (snd ux) (h (S i) (snd ux))). - -lemma compl_g1 : ∀h,s. CF s (auxg h) → CF s (unary_g h). -#h #s #H1 @(CF_compS ? (auxg h) H1) -qed. - -definition aux1g ≝ - λh,ux. max_{i ∈[fst ux,snd ux[ | (λp. eqb (min_input h (fst p) (snd (snd p))) (snd (snd p))) 〈i,ux〉} - ((λp.out (fst p) (snd (snd p)) (h (S (fst p)) (snd (snd p)))) 〈i,ux〉). - -lemma eq_aux : ∀h,x.aux1g h x = auxg h x. -#h #x @same_bigop - [#n #_ >fst_pair >snd_pair // |#n #_ #_ >fst_pair >snd_pair //] -qed. - -lemma compl_g2 : ∀h,s1,s2,s. - CF s1 - (λp:ℕ.eqb (min_input h (fst p) (snd (snd p))) (snd (snd p))) → - CF s2 - (λp:ℕ.out (fst p) (snd (snd p)) (h (S (fst p)) (snd (snd p)))) → - O s (λx.MSC x + ∑_{i ∈[fst x ,snd x[ }(s1 〈i,x〉+s2 〈i,x〉)) → - CF s (auxg h). -#h #s1 #s2 #s #Hs1 #Hs2 #HO @(ext_CF (aux1g h)) - [#n whd in ⊢ (??%%); @eq_aux] -@(CF_max … CF_fst CF_snd Hs1 Hs2 …) @(O_trans … HO) -@O_plus [@O_plus @O_plus_l // | @O_plus_r //] -qed. - -lemma compl_g3 : ∀h,s. - CF s (λp:ℕ.min_input h (fst p) (snd (snd p))) → - CF s (λp:ℕ.eqb (min_input h (fst p) (snd (snd p))) (snd (snd p))). -#h #s #H @(CF_eqb … H) @(CF_comp … CF_snd CF_snd) @(O_trans … (proj1 … H)) -@O_plus // %{1} %{0} #n #_ >commutative_times min_input_def whd in ⊢ (??%?); >minus_S_S @min_f_g #i #_ #_ -whd in ⊢ (??%%); >fst_pair >snd_pair // -qed. - -definition termb_aux ≝ λh. - termb_unary ∘ λp.〈fst (snd p),〈fst p,h (S (fst (snd p))) (fst p)〉〉. - -lemma compl_g4 : ∀h,s1,s. - (CF s1 - (λp.termb (fst (snd p)) (fst p) (h (S (fst (snd p))) (fst p)))) → - (O s (λx.MSC x + ∑_{i ∈[S(fst x) ,S(snd (snd x))[ }(s1 〈i,x〉))) → - CF s (λp:ℕ.min_input h (fst p) (snd (snd p))). -#h #s1 #s #Hs1 #HO @(ext_CF (min_input_aux h)) - [#n whd in ⊢ (??%%); @min_input_eq] -@(CF_mu … MSC MSC … Hs1) - [@CF_compS @CF_fst - |@CF_comp_snd @CF_snd - |@(O_trans … HO) @O_plus [@O_plus @O_plus_l // | @O_plus_r //] -qed. - -(************************* a couple of technical lemmas ***********************) -lemma minus_to_0: ∀a,b. a ≤ b → minus a b = 0. -#a elim a // #n #Hind * - [#H @False_ind /2 by absurd/ | #b normalize #H @Hind @le_S_S_to_le /2/] -qed. - -lemma sigma_bound: ∀h,a,b. monotonic nat le h → - ∑_{i ∈ [a,S b[ }(h i) ≤ (S b-a)*h b. -#h #a #b #H cases (decidable_le a b) - [#leab cut (b = pred (S b - a + a)) - [Hb in match (h b); - generalize in match (S b -a); - #n elim n - [// - |#m #Hind >bigop_Strue [2://] @le_plus - [@H @le_n |@(transitive_le … Hind) @le_times [//] @H //] - ] - |#ltba lapply (not_le_to_lt … ltba) -ltba #ltba - cut (S b -a = 0) [@minus_to_0 //] #Hcut >Hcut // - ] -qed. - -lemma sigma_bound_decr: ∀h,a,b. (∀a1,a2. a1 ≤ a2 → a2 < b → h a2 ≤ h a1) → - ∑_{i ∈ [a,b[ }(h i) ≤ (b-a)*h a. -#h #a #b #H cases (decidable_le a b) - [#leab cut ((b -a) +a ≤ b) [/2 by le_minus_to_plus_r/] generalize in match (b -a); - #n elim n - [// - |#m #Hind >bigop_Strue [2://] #Hm - cut (m+a ≤ b) [@(transitive_le … Hm) //] #Hm1 - @le_plus [@H // |@(transitive_le … (Hind Hm1)) //] - ] - |#ltba lapply (not_le_to_lt … ltba) -ltba #ltba - cut (b -a = 0) [@minus_to_0 @lt_to_le @ltba] #Hcut >Hcut // - ] -qed. - -lemma coroll: ∀s1:nat→nat. (∀n. monotonic ℕ le (λa:ℕ.s1 〈a,n〉)) → -O (λx.(snd (snd x)-fst x)*(s1 〈snd (snd x),x〉)) - (λx.∑_{i ∈[S(fst x) ,S(snd (snd x))[ }(s1 〈i,x〉)). -#s1 #Hs1 %{1} %{0} #n #_ >commutative_times minus_S_S //] -qed. - -lemma coroll2: ∀s1:nat→nat. (∀n,a,b. a ≤ b → b < snd n → s1 〈b,n〉 ≤ s1 〈a,n〉) → -O (λx.(snd x - fst x)*s1 〈fst x,x〉) (λx.∑_{i ∈[fst x,snd x[ }(s1 〈i,x〉)). -#s1 #Hs1 %{1} %{0} #n #_ >commutative_times fst_pair >snd_pair >fst_pair >snd_pair // ] -@(CF_comp … (λx.MSC x + h (S (fst (snd x))) (fst x)) … CF_termb) - [@CF_comp_pair - [@CF_comp_fst @(monotonic_CF … CF_snd) #x // - |@CF_comp_pair - [@(monotonic_CF … CF_fst) #x // - |@(ext_CF ((λx.h (fst x) (snd x))∘(λx.〈S (fst (snd x)),fst x〉))) - [#n normalize >fst_pair >snd_pair %] - @(CF_comp … MSC …hconstr) - [@CF_comp_pair [@CF_compS @CF_comp_fst // |//] - |@O_plus @le_to_O [//|#n >fst_pair >snd_pair //] - ] - ] - ] - |@O_plus - [@O_plus - [@(O_trans … (λx.MSC (fst x) + MSC (max (fst (snd x)) (snd (snd x))))) - [%{2} %{0} #x #_ cases (surj_pair x) #a * #b #eqx >eqx - >fst_pair >snd_pair @(transitive_le … (MSC_pair …)) - >distributive_times_plus @le_plus [//] - cases (surj_pair b) #c * #d #eqb >eqb - >fst_pair >snd_pair @(transitive_le … (MSC_pair …)) - whd in ⊢ (??%); @le_plus - [@monotonic_MSC @(le_maxl … (le_n …)) - |>commutative_times fst_pair >snd_pair // qed. - -lemma le_big : ∀x. x ≤ big x. -#x cases (surj_pair x) #a * #b #eqx >eqx @le_pair >fst_pair >snd_pair -[@(le_maxl … (le_n …)) | @(le_maxr … (le_n …))] -qed. - -definition faux2 ≝ λh. - (λx.MSC x + (snd (snd x)-fst x)* - (λx.sU 〈max (fst(snd x)) (snd(snd x)),〈fst x,h (S (fst (snd x))) (fst x)〉〉) 〈snd (snd x),x〉). - -lemma compl_g7: ∀h. - constructible (λx. h (fst x) (snd x)) → - (∀n. monotonic ? le (h n)) → - CF (λx.MSC x + (snd (snd x)-fst x)*sU 〈max (fst x) (snd x),〈snd (snd x),h (S (fst x)) (snd (snd x))〉〉) - (λp:ℕ.min_input h (fst p) (snd (snd p))). -#h #hcostr #hmono @(monotonic_CF … (faux2 h)) - [#n normalize >fst_pair >snd_pair //] -@compl_g5 [2:@(compl_g6 h hcostr)] #n #x #y #lexy >fst_pair >snd_pair ->fst_pair >snd_pair @monotonic_sU // @hmono @lexy -qed. - -lemma compl_g71: ∀h. - constructible (λx. h (fst x) (snd x)) → - (∀n. monotonic ? le (h n)) → - CF (λx.MSC (big x) + (snd (snd x)-fst x)*sU 〈max (fst x) (snd x),〈snd (snd x),h (S (fst x)) (snd (snd x))〉〉) - (λp:ℕ.min_input h (fst p) (snd (snd p))). -#h #hcostr #hmono @(monotonic_CF … (compl_g7 h hcostr hmono)) #x -@le_plus [@monotonic_MSC //] -cases (decidable_le (fst x) (snd(snd x))) - [#Hle @le_times // @monotonic_sU - |#Hlt >(minus_to_0 … (lt_to_le … )) [// | @not_le_to_lt @Hlt] - ] -qed. - -definition out_aux ≝ λh. - out_unary ∘ λp.〈fst p,〈snd(snd p),h (S (fst p)) (snd (snd p))〉〉. - -lemma compl_g8: ∀h. - constructible (λx. h (fst x) (snd x)) → - (CF (λx. sU 〈max (fst x) (snd x),〈snd(snd x),h (S (fst x)) (snd(snd x))〉〉) - (λp.out (fst p) (snd (snd p)) (h (S (fst p)) (snd (snd p))))). -#h #hconstr @(ext_CF (out_aux h)) - [#n normalize >fst_pair >snd_pair >fst_pair >snd_pair // ] -@(CF_comp … (λx.h (S (fst x)) (snd(snd x)) + MSC x) … CF_out) - [@CF_comp_pair - [@(monotonic_CF … CF_fst) #x // - |@CF_comp_pair - [@CF_comp_snd @(monotonic_CF … CF_snd) #x // - |@(ext_CF ((λx.h (fst x) (snd x))∘(λx.〈S (fst x),snd(snd x)〉))) - [#n normalize >fst_pair >snd_pair %] - @(CF_comp … MSC …hconstr) - [@CF_comp_pair [@CF_compS // | @CF_comp_snd // ] - |@O_plus @le_to_O [//|#n >fst_pair >snd_pair //] - ] - ] - ] - |@O_plus - [@O_plus - [@le_to_O #n @sU_le - |@(O_trans … (λx.MSC (max (fst x) (snd x)))) - [%{2} %{0} #x #_ cases (surj_pair x) #a * #b #eqx >eqx - >fst_pair >snd_pair @(transitive_le … (MSC_pair …)) - whd in ⊢ (??%); @le_plus - [@monotonic_MSC @(le_maxl … (le_n …)) - |>commutative_times (times_n_1 (MSC x)) >commutative_times @le_times - [// | @monotonic_MSC // ]] -@(O_trans … (coroll2 ??)) - [#n #a #b #leab #ltb >fst_pair >fst_pair >snd_pair >snd_pair - cut (b ≤ n) [@(transitive_le … (le_snd …)) @lt_to_le //] #lebn - cut (max a n = n) - [normalize >le_to_leb_true [//|@(transitive_le … leab lebn)]] #maxa - cut (max b n = n) [normalize >le_to_leb_true //] #maxb - @le_plus - [@le_plus [>big_def >big_def >maxa >maxb //] - @le_times - [/2 by monotonic_le_minus_r/ - |@monotonic_sU // @hantimono [@le_S_S // |@ltb] - ] - |@monotonic_sU // @hantimono [@le_S_S // |@ltb] - ] - |@le_to_O #n >fst_pair >snd_pair - cut (max (fst n) n = n) [normalize >le_to_leb_true //] #Hmax >Hmax - >associative_plus >distributive_times_plus - @le_plus [@le_times [@le_S // |>big_def >Hmax //] |//] - ] -qed. - -definition sg ≝ λh,x. - (S (snd x-fst x))*MSC 〈x,x〉 + (snd x-fst x)*(S(snd x-fst x))*sU 〈x,〈snd x,h (S (fst x)) (snd x)〉〉. - -lemma sg_def : ∀h,a,b. - sg h 〈a,b〉 = (S (b-a))*MSC 〈〈a,b〉,〈a,b〉〉 + - (b-a)*(S(b-a))*sU 〈〈a,b〉,〈b,h (S a) b〉〉. -#h #a #b whd in ⊢ (??%?); >fst_pair >snd_pair // -qed. - -lemma compl_g11 : ∀h. - constructible (λx. h (fst x) (snd x)) → - (∀n. monotonic ? le (h n)) → - (∀n,a,b. a ≤ b → b ≤ n → h b n ≤ h a n) → - CF (sg h) (unary_g h). -#h #hconstr #Hm #Ham @compl_g1 @(compl_g9 h hconstr Hm Ham) -qed. - -(**************************** closing the argument ****************************) - -let rec h_of_aux (r:nat →nat) (c,d,b:nat) on d : nat ≝ - match d with - [ O ⇒ c - | S d1 ⇒ (S d)*(MSC 〈〈b-d,b〉,〈b-d,b〉〉) + - d*(S d)*sU 〈〈b-d,b〉,〈b,r (h_of_aux r c d1 b)〉〉]. - -lemma h_of_aux_O: ∀r,c,b. - h_of_aux r c O b = c. -// qed. - -lemma h_of_aux_S : ∀r,c,d,b. - h_of_aux r c (S d) b = - (S (S d))*(MSC 〈〈b-(S d),b〉,〈b-(S d),b〉〉) + - (S d)*(S (S d))*sU 〈〈b-(S d),b〉,〈b,r(h_of_aux r c d b)〉〉. -// qed. - -definition h_of ≝ λr,p. - let m ≝ max (fst p) (snd p) in - h_of_aux r (MSC 〈〈m,m〉,〈m,m〉〉) (snd p - fst p) (snd p). - -lemma h_of_O: ∀r,a,b. b ≤ a → - h_of r 〈a,b〉 = let m ≝ max a b in MSC 〈〈m,m〉,〈m,m〉〉. -#r #a #b #Hle normalize >fst_pair >snd_pair >(minus_to_0 … Hle) // -qed. - -lemma h_of_def: ∀r,a,b.h_of r 〈a,b〉 = - let m ≝ max a b in - h_of_aux r (MSC 〈〈m,m〉,〈m,m〉〉) (b - a) b. -#r #a #b normalize >fst_pair >snd_pair // -qed. - -lemma mono_h_of_aux: ∀r.(∀x. x ≤ r x) → monotonic ? le r → - ∀d,d1,c,c1,b,b1.c ≤ c1 → d ≤ d1 → b ≤ b1 → - h_of_aux r c d b ≤ h_of_aux r c1 d1 b1. -#r #Hr #monor #d #d1 lapply d -d elim d1 - [#d #c #c1 #b #b1 #Hc #Hd @(le_n_O_elim ? Hd) #leb - >h_of_aux_O >h_of_aux_O // - |#m #Hind #d #c #c1 #b #b1 #lec #led #leb cases (le_to_or_lt_eq … led) - [#ltd @(transitive_le … (Hind … lec ? leb)) [@le_S_S_to_le @ltd] - >h_of_aux_S @(transitive_le ???? (le_plus_n …)) - >(times_n_1 (h_of_aux r c1 m b1)) in ⊢ (?%?); - >commutative_times @le_times [//|@(transitive_le … (Hr ?)) @sU_le] - |#Hd >Hd >h_of_aux_S >h_of_aux_S - cut (b-S m ≤ b1 - S m) [/2 by monotonic_le_minus_l/] #Hb1 - @le_plus [@le_times //] - [@monotonic_MSC @le_pair @le_pair // - |@le_times [//] @monotonic_sU - [@le_pair // |// |@monor @Hind //] - ] - ] - ] -qed. - -lemma mono_h_of2: ∀r.(∀x. x ≤ r x) → monotonic ? le r → - ∀i,b,b1. b ≤ b1 → h_of r 〈i,b〉 ≤ h_of r 〈i,b1〉. -#r #Hr #Hmono #i #a #b #leab >h_of_def >h_of_def -cut (max i a ≤ max i b) - [@to_max - [@(le_maxl … (le_n …))|@(transitive_le … leab) @(le_maxr … (le_n …))]] -#Hmax @(mono_h_of_aux r Hr Hmono) - [@monotonic_MSC @le_pair @le_pair @Hmax |/2 by monotonic_le_minus_l/ |@leab] -qed. - -axiom h_of_constr : ∀r:nat →nat. - (∀x. x ≤ r x) → monotonic ? le r → constructible r → - constructible (h_of r). - -lemma speed_compl: ∀r:nat →nat. - (∀x. x ≤ r x) → monotonic ? le r → constructible r → - CF (h_of r) (unary_g (λi,x. r(h_of r 〈i,x〉))). -#r #Hr #Hmono #Hconstr @(monotonic_CF … (compl_g11 …)) - [#x cases (surj_pair x) #a * #b #eqx >eqx - >sg_def cases (decidable_le b a) - [#leba >(minus_to_0 … leba) normalize in ⊢ (?%?); - h_of_def - cut (max a b = a) - [normalize cases (le_to_or_lt_eq … leba) - [#ltba >(lt_to_leb_false … ltba) % - |#eqba (le_to_leb_true … (le_n ?)) % ]] - #Hmax >Hmax normalize >(minus_to_0 … leba) normalize - @monotonic_MSC @le_pair @le_pair // - |#ltab >h_of_def >h_of_def - cut (max a b = b) - [normalize >(le_to_leb_true … ) [%] @lt_to_le @not_le_to_lt @ltab] - #Hmax >Hmax - cut (max (S a) b = b) - [whd in ⊢ (??%?); >(le_to_leb_true … ) [%] @not_le_to_lt @ltab] - #Hmax1 >Hmax1 - cut (∃d.b - a = S d) - [%{(pred(b-a))} >S_pred [//] @lt_plus_to_minus_r @not_le_to_lt @ltab] - * #d #eqd >eqd - cut (b-S a = d) [//] #eqd1 >eqd1 >h_of_aux_S >eqd1 - cut (b - S d = a) - [@plus_to_minus >commutative_plus @minus_to_plus - [@lt_to_le @not_le_to_lt // | //]] #eqd2 >eqd2 - normalize // - ] - |#n #a #b #leab #lebn >h_of_def >h_of_def - cut (max a n = n) - [normalize >le_to_leb_true [%|@(transitive_le … leab lebn)]] #Hmaxa - cut (max b n = n) - [normalize >(le_to_leb_true … lebn) %] #Hmaxb - >Hmaxa >Hmaxb @Hmono @(mono_h_of_aux r … Hr Hmono) // /2 by monotonic_le_minus_r/ - |#n #a #b #leab @Hmono @(mono_h_of2 … Hr Hmono … leab) - |@(constr_comp … Hconstr Hr) @(ext_constr (h_of r)) - [#x cases (surj_pair x) #a * #b #eqx >eqx >fst_pair >snd_pair //] - @(h_of_constr r Hr Hmono Hconstr) - ] -qed. - -lemma speed_compl_i: ∀r:nat →nat. - (∀x. x ≤ r x) → monotonic ? le r → constructible r → - ∀i. CF (λx.h_of r 〈i,x〉) (λx.g (λi,x. r(h_of r 〈i,x〉)) i x). -#r #Hr #Hmono #Hconstr #i -@(ext_CF (λx.unary_g (λi,x. r(h_of r 〈i,x〉)) 〈i,x〉)) - [#n whd in ⊢ (??%%); @eq_f @sym_eq >fst_pair >snd_pair %] -@smn @(ext_CF … (speed_compl r Hr Hmono Hconstr)) #n // -qed. - -(**************************** the speedup theorem *****************************) -theorem pseudo_speedup: - ∀r:nat →nat. (∀x. x ≤ r x) → monotonic ? le r → constructible r → - ∃f.∀sf. CF sf f → ∃g,sg. f ≈ g ∧ CF sg g ∧ O sf (r ∘ sg). -(* ∃m,a.∀n. a≤n → r(sg a) < m * sf n. *) -#r #Hr #Hmono #Hconstr -(* f is (g (λi,x. r(h_of r 〈i,x〉)) 0) *) -%{(g (λi,x. r(h_of r 〈i,x〉)) 0)} #sf * #H * #i * -#Hcodei #HCi -(* g is (g (λi,x. r(h_of r 〈i,x〉)) (S i)) *) -%{(g (λi,x. r(h_of r 〈i,x〉)) (S i))} -(* sg is (λx.h_of r 〈i,x〉) *) -%{(λx. h_of r 〈S i,x〉)} -lapply (speed_compl_i … Hr Hmono Hconstr (S i)) #Hg -%[%[@condition_1 |@Hg] - |cases Hg #H1 * #j * #Hcodej #HCj - lapply (condition_2 … Hcodei) #Hcond2 (* @not_to_not *) - cases HCi #m * #a #Ha %{m} %{(max (S i) a)} #n #ltin @lt_to_le @not_le_to_lt - @(not_to_not … Hcond2) -Hcond2 #Hlesf %{n} % - [@(transitive_le … ltin) @(le_maxl … (le_n …))] - cases (Ha n ?) [2: @(transitive_le … ltin) @(le_maxr … (le_n …))] - #y #Uy %{y} @(monotonic_U … Uy) @(transitive_le … Hlesf) // - ] -qed. - -theorem pseudo_speedup': - ∀r:nat →nat. (∀x. x ≤ r x) → monotonic ? le r → constructible r → - ∃f.∀sf. CF sf f → ∃g,sg. f ≈ g ∧ CF sg g ∧ - (* ¬ O (r ∘ sg) sf. *) - ∃m,a.∀n. a≤n → r(sg a) < m * sf n. -#r #Hr #Hmono #Hconstr -(* f is (g (λi,x. r(h_of r 〈i,x〉)) 0) *) -%{(g (λi,x. r(h_of r 〈i,x〉)) 0)} #sf * #H * #i * -#Hcodei #HCi -(* g is (g (λi,x. r(h_of r 〈i,x〉)) (S i)) *) -%{(g (λi,x. r(h_of r 〈i,x〉)) (S i))} -(* sg is (λx.h_of r 〈i,x〉) *) -%{(λx. h_of r 〈S i,x〉)} -lapply (speed_compl_i … Hr Hmono Hconstr (S i)) #Hg -%[%[@condition_1 |@Hg] - |cases Hg #H1 * #j * #Hcodej #HCj - lapply (condition_2 … Hcodei) #Hcond2 (* @not_to_not *) - cases HCi #m * #a #Ha - %{m} %{(max (S i) a)} #n #ltin @not_le_to_lt @(not_to_not … Hcond2) -Hcond2 #Hlesf - %{n} % [@(transitive_le … ltin) @(le_maxl … (le_n …))] - cases (Ha n ?) [2: @(transitive_le … ltin) @(le_maxr … (le_n …))] - #y #Uy %{y} @(monotonic_U … Uy) @(transitive_le … Hlesf) - @Hmono @(mono_h_of2 … Hr Hmono … ltin) - ] -qed. -