X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Flib%2Fbasics%2Fstar.ma;h=391e085309e3ee2cbc9f535ee07af7f2179f34a1;hb=4adf9860cd26175c4d73b73e8adbb3c6ceaa19c9;hp=36aee8fe45465c016a6ca3709046a0c6fefd11c7;hpb=380ceb6b6552fd9ebd48d710ab12931d5d97e465;p=helm.git diff --git a/matita/matita/lib/basics/star.ma b/matita/matita/lib/basics/star.ma index 36aee8fe4..391e08530 100644 --- a/matita/matita/lib/basics/star.ma +++ b/matita/matita/lib/basics/star.ma @@ -142,7 +142,7 @@ lemma star_ind_l: ∀A,R,a2. ∀P:predicate A. @(star_ind_l_aux … H1 H2 … Ha12) // qed. -(* RC and star *) +(* TC and star *) lemma TC_to_star: ∀A,R,a,b.TC A R a b → star A R a b. #R #A #a #b #TCH (elim TCH) /2/ @@ -193,249 +193,3 @@ lemma WF_antimonotonic: ∀A,R,S. subR A R S → #H #Hind % #c #Rcb @Hind @subRS // qed. -(* added from lambda_delta *) - -lemma TC_strap: ∀A. ∀R:relation A. ∀a1,a,a2. - R a1 a → TC … R a a2 → TC … R a1 a2. -/3 width=3/ qed. - -lemma TC_reflexive: ∀A,R. reflexive A R → reflexive A (TC … R). -/2 width=1/ qed. - -lemma TC_star_ind: ∀A,R. reflexive A R → ∀a1. ∀P:predicate A. - P a1 → (∀a,a2. TC … R a1 a → R a a2 → P a → P a2) → - ∀a2. TC … R a1 a2 → P a2. -#A #R #H #a1 #P #Ha1 #IHa1 #a2 #Ha12 elim Ha12 -a2 /3 width=4/ -qed-. - -inductive TC_dx (A:Type[0]) (R:relation A): A → A → Prop ≝ - |inj_dx: ∀a,c. R a c → TC_dx A R a c - |step_dx : ∀a,b,c. R a b → TC_dx A R b c → TC_dx A R a c. - -lemma TC_dx_strap: ∀A. ∀R: relation A. - ∀a,b,c. TC_dx A R a b → R b c → TC_dx A R a c. -#A #R #a #b #c #Hab elim Hab -a -b /3 width=3/ -qed. - -lemma TC_to_TC_dx: ∀A. ∀R: relation A. - ∀a1,a2. TC … R a1 a2 → TC_dx … R a1 a2. -#A #R #a1 #a2 #Ha12 elim Ha12 -a2 /2 width=3/ -qed. - -lemma TC_dx_to_TC: ∀A. ∀R: relation A. - ∀a1,a2. TC_dx … R a1 a2 → TC … R a1 a2. -#A #R #a1 #a2 #Ha12 elim Ha12 -a1 -a2 /2 width=3/ -qed. - -fact TC_ind_dx_aux: ∀A,R,a2. ∀P:predicate A. - (∀a1. R a1 a2 → P a1) → - (∀a1,a. R a1 a → TC … R a a2 → P a → P a1) → - ∀a1,a. TC … R a1 a → a = a2 → P a1. -#A #R #a2 #P #H1 #H2 #a1 #a #Ha1 -elim (TC_to_TC_dx ???? Ha1) -a1 -a -[ #a #c #Hac #H destruct /2 width=1/ -| #a #b #c #Hab #Hbc #IH #H destruct /3 width=4/ -] -qed-. - -lemma TC_ind_dx: ∀A,R,a2. ∀P:predicate A. - (∀a1. R a1 a2 → P a1) → - (∀a1,a. R a1 a → TC … R a a2 → P a → P a1) → - ∀a1. TC … R a1 a2 → P a1. -#A #R #a2 #P #H1 #H2 #a1 #Ha12 -@(TC_ind_dx_aux … H1 H2 … Ha12) // -qed-. - -lemma TC_symmetric: ∀A,R. symmetric A R → symmetric A (TC … R). -#A #R #HR #x #y #H @(TC_ind_dx ??????? H) -x /3 width=1/ /3 width=3/ -qed. - -lemma TC_star_ind_dx: ∀A,R. reflexive A R → - ∀a2. ∀P:predicate A. P a2 → - (∀a1,a. R a1 a → TC … R a a2 → P a → P a1) → - ∀a1. TC … R a1 a2 → P a1. -#A #R #HR #a2 #P #Ha2 #H #a1 #Ha12 -@(TC_ind_dx … P ? H … Ha12) /3 width=4/ -qed-. - -definition Conf3: ∀A,B. relation2 A B → relation A → Prop ≝ λA,B,S,R. - ∀b,a1. S a1 b → ∀a2. R a1 a2 → S a2 b. - -lemma TC_Conf3: ∀A,B,S,R. Conf3 A B S R → Conf3 A B S (TC … R). -#A #B #S #R #HSR #b #a1 #Ha1 #a2 #H elim H -a2 /2 width=3/ -qed. - -inductive bi_TC (A,B:Type[0]) (R:bi_relation A B) (a:A) (b:B): relation2 A B ≝ - |bi_inj : ∀c,d. R a b c d → bi_TC A B R a b c d - |bi_step: ∀c,d,e,f. bi_TC A B R a b c d → R c d e f → bi_TC A B R a b e f. - -lemma bi_TC_strap: ∀A,B. ∀R:bi_relation A B. ∀a1,a,a2,b1,b,b2. - R a1 b1 a b → bi_TC … R a b a2 b2 → bi_TC … R a1 b1 a2 b2. -#A #B #R #a1 #a #a2 #b1 #b #b2 #HR #H elim H -a2 -b2 /2 width=4/ /3 width=4/ -qed. - -lemma bi_TC_reflexive: ∀A,B,R. bi_reflexive A B R → - bi_reflexive A B (bi_TC … R). -/2 width=1/ qed. - -inductive bi_TC_dx (A,B:Type[0]) (R:bi_relation A B): bi_relation A B ≝ - |bi_inj_dx : ∀a1,a2,b1,b2. R a1 b1 a2 b2 → bi_TC_dx A B R a1 b1 a2 b2 - |bi_step_dx : ∀a1,a,a2,b1,b,b2. R a1 b1 a b → bi_TC_dx A B R a b a2 b2 → - bi_TC_dx A B R a1 b1 a2 b2. - -lemma bi_TC_dx_strap: ∀A,B. ∀R: bi_relation A B. - ∀a1,a,a2,b1,b,b2. bi_TC_dx A B R a1 b1 a b → - R a b a2 b2 → bi_TC_dx A B R a1 b1 a2 b2. -#A #B #R #a1 #a #a2 #b1 #b #b2 #H1 elim H1 -a -b /3 width=4/ -qed. - -lemma bi_TC_to_bi_TC_dx: ∀A,B. ∀R: bi_relation A B. - ∀a1,a2,b1,b2. bi_TC … R a1 b1 a2 b2 → - bi_TC_dx … R a1 b1 a2 b2. -#A #B #R #a1 #a2 #b1 #b2 #H12 elim H12 -a2 -b2 /2 width=4/ -qed. - -lemma bi_TC_dx_to_bi_TC: ∀A,B. ∀R: bi_relation A B. - ∀a1,a2,b1,b2. bi_TC_dx … R a1 b1 a2 b2 → - bi_TC … R a1 b1 a2 b2. -#A #b #R #a1 #a2 #b1 #b2 #H12 elim H12 -a1 -a2 -b1 -b2 /2 width=4/ -qed. - -fact bi_TC_ind_dx_aux: ∀A,B,R,a2,b2. ∀P:relation2 A B. - (∀a1,b1. R a1 b1 a2 b2 → P a1 b1) → - (∀a1,a,b1,b. R a1 b1 a b → bi_TC … R a b a2 b2 → P a b → P a1 b1) → - ∀a1,a,b1,b. bi_TC … R a1 b1 a b → a = a2 → b = b2 → P a1 b1. -#A #B #R #a2 #b2 #P #H1 #H2 #a1 #a #b1 #b #H1 -elim (bi_TC_to_bi_TC_dx ??????? H1) -a1 -a -b1 -b -[ #a1 #x #b1 #y #H1 #Hx #Hy destruct /2 width=1/ -| #a1 #a #x #b1 #b #y #H1 #H #IH #Hx #Hy destruct /3 width=5/ -] -qed-. - -lemma bi_TC_ind_dx: ∀A,B,R,a2,b2. ∀P:relation2 A B. - (∀a1,b1. R a1 b1 a2 b2 → P a1 b1) → - (∀a1,a,b1,b. R a1 b1 a b → bi_TC … R a b a2 b2 → P a b → P a1 b1) → - ∀a1,b1. bi_TC … R a1 b1 a2 b2 → P a1 b1. -#A #B #R #a2 #b2 #P #H1 #H2 #a1 #b1 #H12 -@(bi_TC_ind_dx_aux ?????? H1 H2 … H12) // -qed-. - -lemma bi_TC_symmetric: ∀A,B,R. bi_symmetric A B R → - bi_symmetric A B (bi_TC … R). -#A #B #R #HR #a1 #a2 #b1 #b2 #H21 -@(bi_TC_ind_dx ?????????? H21) -a2 -b2 /3 width=1/ /3 width=4/ -qed. - -lemma bi_TC_transitive: ∀A,B,R. bi_transitive A B (bi_TC … R). -#A #B #R #a1 #a #b1 #b #H elim H -a -b /2 width=4/ /3 width=4/ -qed. - -definition bi_Conf3: ∀A,B,C. relation3 A B C → bi_relation A B → Prop ≝ λA,B,C,S,R. - ∀c,a1,b1. S a1 b1 c → ∀a2,b2. R a1 b1 a2 b2 → S a2 b2 c. - -lemma bi_TC_Conf3: ∀A,B,C,S,R. bi_Conf3 A B C S R → bi_Conf3 A B C S (bi_TC … R). -#A #B #C #S #R #HSR #c #a1 #b1 #Hab1 #a2 #b2 #H elim H -a2 -b2 /2 width=4/ -qed. - -lemma bi_TC_star_ind: ∀A,B,R. bi_reflexive A B R → ∀a1,b1. ∀P:relation2 A B. - P a1 b1 → (∀a,a2,b,b2. bi_TC … R a1 b1 a b → R a b a2 b2 → P a b → P a2 b2) → - ∀a2,b2. bi_TC … R a1 b1 a2 b2 → P a2 b2. -#A #B #R #HR #a1 #b1 #P #H1 #IH #a2 #b2 #H12 elim H12 -a2 -b2 /3 width=5/ -qed-. - -lemma bi_TC_star_ind_dx: ∀A,B,R. bi_reflexive A B R → - ∀a2,b2. ∀P:relation2 A B. P a2 b2 → - (∀a1,a,b1,b. R a1 b1 a b → bi_TC … R a b a2 b2 → P a b → P a1 b1) → - ∀a1,b1. bi_TC … R a1 b1 a2 b2 → P a1 b1. -#A #B #R #HR #a2 #b2 #P #H2 #IH #a1 #b1 #H12 -@(bi_TC_ind_dx … P ? IH … H12) /3 width=5/ -qed-. - -definition bi_star: ∀A,B,R. bi_relation A B ≝ λA,B,R,a1,b1,a2,b2. - (a1 = a2 ∧ b1 = b2) ∨ bi_TC A B R a1 b1 a2 b2. - -lemma bi_star_bi_reflexive: ∀A,B,R. bi_reflexive A B (bi_star … R). -/3 width=1/ qed. - -lemma bi_TC_to_bi_star: ∀A,B,R,a1,b1,a2,b2. - bi_TC A B R a1 b1 a2 b2 → bi_star A B R a1 b1 a2 b2. -/2 width=1/ qed. - -lemma bi_R_to_bi_star: ∀A,B,R,a1,b1,a2,b2. - R a1 b1 a2 b2 → bi_star A B R a1 b1 a2 b2. -/3 width=1/ qed. - -lemma bi_star_strap1: ∀A,B,R,a1,a,a2,b1,b,b2. bi_star A B R a1 b1 a b → - R a b a2 b2 → bi_star A B R a1 b1 a2 b2. -#A #B #R #a1 #a #a2 #b1 #b #b2 * -[ * #H1 #H2 destruct /2 width=1/ -| /3 width=4/ -] -qed. - -lemma bi_star_strap2: ∀A,B,R,a1,a,a2,b1,b,b2. R a1 b1 a b → - bi_star A B R a b a2 b2 → bi_star A B R a1 b1 a2 b2. -#A #B #R #a1 #a #a2 #b1 #b #b2 #H * -[ * #H1 #H2 destruct /2 width=1/ -| /3 width=4/ -] -qed. - -lemma bi_star_to_bi_TC_to_bi_TC: ∀A,B,R,a1,a,a2,b1,b,b2. bi_star A B R a1 b1 a b → - bi_TC A B R a b a2 b2 → bi_TC A B R a1 b1 a2 b2. -#A #B #R #a1 #a #a2 #b1 #b #b2 * -[ * #H1 #H2 destruct /2 width=1/ -| /2 width=4/ -] -qed. - -lemma bi_TC_to_bi_star_to_bi_TC: ∀A,B,R,a1,a,a2,b1,b,b2. bi_TC A B R a1 b1 a b → - bi_star A B R a b a2 b2 → bi_TC A B R a1 b1 a2 b2. -#A #B #R #a1 #a #a2 #b1 #b #b2 #H * -[ * #H1 #H2 destruct /2 width=1/ -| /2 width=4/ -] -qed. - -lemma bi_tansitive_bi_star: ∀A,B,R. bi_transitive A B (bi_star … R). -#A #B #R #a1 #a #b1 #b #H #a2 #b2 * -[ * #H1 #H2 destruct /2 width=1/ -| /3 width=4/ -] -qed. - -lemma bi_star_ind: ∀A,B,R,a1,b1. ∀P:relation2 A B. P a1 b1 → - (∀a,a2,b,b2. bi_star … R a1 b1 a b → R a b a2 b2 → P a b → P a2 b2) → - ∀a2,b2. bi_star … R a1 b1 a2 b2 → P a2 b2. -#A #B #R #a1 #b1 #P #H #IH #a2 #b2 * -[ * #H1 #H2 destruct // -| #H12 elim H12 -a2 -b2 /2 width=5/ -H /3 width=5/ -] -qed-. - -lemma bi_star_ind_dx: ∀A,B,R,a2,b2. ∀P:relation2 A B. P a2 b2 → - (∀a1,a,b1,b. R a1 b1 a b → bi_star … R a b a2 b2 → P a b → P a1 b1) → - ∀a1,b1. bi_star … R a1 b1 a2 b2 → P a1 b1. -#A #B #R #a2 #b2 #P #H #IH #a1 #b1 * -[ * #H1 #H2 destruct // -| #H12 @(bi_TC_ind_dx ?????????? H12) -a1 -b1 /2 width=5/ -H /3 width=5/ -] -qed-. - -(* ************ confluence of star *****************) - -lemma star_strip: ∀A,R. confluent A R → - ∀a0,a1. star … R a0 a1 → ∀a2. R a0 a2 → - ∃∃a. R a1 a & star … R a2 a. -#A #R #HR #a0 #a1 #H elim H -a1 /2 width=3/ -#a #a1 #_ #Ha1 #IHa0 #a2 #Ha02 -elim (IHa0 … Ha02) -a0 #a0 #Ha0 #Ha20 -elim (HR … Ha1 … Ha0) -a /3 width=5/ -qed-. - -lemma star_confluent: ∀A,R. confluent A R → confluent A (star … R). -#A #R #HR #a0 #a1 #H elim H -a1 /2 width=3/ -#a #a1 #_ #Ha1 #IHa0 #a2 #Ha02 -elim (IHa0 … Ha02) -a0 #a0 #Ha0 #Ha20 -elim (star_strip … HR … Ha0 … Ha1) -a /3 width=5/ -qed-.