X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Fcontribs%2Fdama%2Fdama%2Fproperty_exhaustivity.ma;h=deddf88049f5e60a2108942506b67a65bf79bf80;hb=179574c117d34a39cebeaa66673cda83974e135a;hp=00f8cb25917339cc960f25c510f5b5a4a00b31c8;hpb=b284579a0c4d45bc8483f295434a465ca685f444;p=helm.git diff --git a/helm/software/matita/contribs/dama/dama/property_exhaustivity.ma b/helm/software/matita/contribs/dama/dama/property_exhaustivity.ma index 00f8cb259..deddf8804 100644 --- a/helm/software/matita/contribs/dama/dama/property_exhaustivity.ma +++ b/helm/software/matita/contribs/dama/dama/property_exhaustivity.ma @@ -13,12 +13,159 @@ (**************************************************************************) include "ordered_uniform.ma". +include "property_sigma.ma". + +lemma h_segment_upperbound: + ∀C:half_ordered_set. + ∀s:segment C. + ∀a:sequence (half_segment_ordered_set C s). + upper_bound ? ⌊n,\fst (a n)⌋ (seg_u C s). +intros 4; simplify; cases (a n); simplify; unfold in H; +cases (wloss_prop C); rewrite < H1 in H; simplify; cases H; +assumption; +qed. + +notation "'segment_upperbound'" non associative with precedence 90 for @{'segment_upperbound}. +notation "'segment_lowerbound'" non associative with precedence 90 for @{'segment_lowerbound}. + +interpretation "segment_upperbound" 'segment_upperbound = (h_segment_upperbound (os_l _)). +interpretation "segment_lowerbound" 'segment_lowerbound = (h_segment_upperbound (os_r _)). + +lemma h_segment_preserves_uparrow: + ∀C:half_ordered_set.∀s:segment C.∀a:sequence (half_segment_ordered_set C s). + ∀x,h. uparrow C ⌊n,\fst (a n)⌋ x → uparrow (half_segment_ordered_set C s) a ≪x,h≫. +intros; cases H (Ha Hx); split; +[ intro n; intro H; apply (Ha n); apply rule H; +| cases Hx; split; + [ intro n; intro H; apply (H1 n);apply rule H; + | intros; cases (H2 (\fst y)); [2: apply rule H3;] + exists [apply w] apply (x2sx_ ?? (a w) y H4);]] +qed. + +notation "'segment_preserves_uparrow'" non associative with precedence 90 for @{'segment_preserves_uparrow}. +notation "'segment_preserves_downarrow'" non associative with precedence 90 for @{'segment_preserves_downarrow}. + +interpretation "segment_preserves_uparrow" 'segment_preserves_uparrow = (h_segment_preserves_uparrow (os_l _)). +interpretation "segment_preserves_downarrow" 'segment_preserves_downarrow = (h_segment_preserves_uparrow (os_r _)). + +(* Fact 2.18 *) +lemma segment_cauchy: + ∀C:ordered_uniform_space.∀s:‡C.∀a:sequence {[s]}. + a is_cauchy → ⌊n,\fst (a n)⌋ is_cauchy. +intros 6; +alias symbol "pi1" (instance 3) = "pair pi1". +alias symbol "pi2" = "pair pi2". +apply (H (λx:{[s]} squareB.U 〈\fst (\fst x),\fst (\snd x)〉)); +(unfold segment_ordered_uniform_space; simplify); +exists [apply U] split; [assumption;] +intro; cases b; intros; simplify; split; intros; assumption; +qed. (* Definition 3.7 *) -definition exhaustivity ≝ +definition exhaustive ≝ λC:ordered_uniform_space. ∀a,b:sequence C. (a is_increasing → a is_upper_located → a is_cauchy) ∧ (b is_decreasing → b is_lower_located → b is_cauchy). - -(* Lemma 3.8 *) + +lemma h_uparrow_to_in_segment: + ∀C:half_ordered_set. + ∀s:segment C. + ∀a:sequence C. + (∀i.a i ∈ s) → + ∀x:C. uparrow C a x → + in_segment C s x. +intros (C H a H1 x H2); unfold in H2; cases H2; clear H2;unfold in H3 H4; cases H4; clear H4; unfold in H2; +cases (wloss_prop C) (W W); apply prove_in_segment; unfold; +[ apply (hle_transitive ??? x ? (H2 O)); lapply (H1 O) as K; unfold in K; rewrite