X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;ds=sidebyside;f=helm%2Fsoftware%2Fmatita%2Fdama%2Fordered_fields_ch0.ma;h=4a7b7a2662a0906dba90eb95b7f07e0e5d5e48fd;hb=c6b621c1df5abd9a8a1567991379768c435607dd;hp=d95108eb327faa8d6d382b3a4ed5be5971e48750;hpb=85fce74d6a0cd8e83e59895e81f1bc09d21ef4c2;p=helm.git

diff --git a/helm/software/matita/dama/ordered_fields_ch0.ma b/helm/software/matita/dama/ordered_fields_ch0.ma
index d95108eb3..4a7b7a266 100644
--- a/helm/software/matita/dama/ordered_fields_ch0.ma
+++ b/helm/software/matita/dama/ordered_fields_ch0.ma
@@ -15,45 +15,71 @@
 set "baseuri" "cic:/matita/ordered_fields_ch0/".
 
 include "fields.ma".
+include "ordered_sets.ma".
 
-record is_ordered_field_ch0 (F:field) (le:F→F→Prop) : Prop \def
+(*CSC: non capisco questi alias! Una volta non servivano*)
+alias id "plus" = "cic:/matita/groups/plus.con".
+alias symbol "plus" = "Abelian group plus".
+record is_ordered_field_ch0 (F:field) (le:F→F→Prop) : Type \def
  { of_mult_compat: ∀a,b. le 0 a → le 0 b → le 0 (a*b);
    of_plus_compat: ∀a,b,c. le a b → le (a+c) (b+c);
    of_weak_tricotomy : ∀a,b. a≠b → le a b ∨ le b a;
    (* 0 characteristics *)
-   of_char0: ∀n. n > O → sum ? (plus F) 0 1 n ≠ 0
+   (*CSC: qua c'era un ? al posto di F *)
+   of_char0: ∀n. n > O → sum F (plus F) 0 1 n ≠ 0
  }.
  
 record ordered_field_ch0 : Type \def
  { of_field:> field;
-   of_le: of_field → of_field → Prop;
-   of_ordered_field_properties:> is_ordered_field_ch0 of_field of_le
+   of_ordered_set:> ordered_set of_field;
+   of_reflexive: reflexive ? (os_le ? of_ordered_set);
+   of_antisimmetric: antisimmetric ? (os_le ? of_ordered_set);
+   of_cotransitive: cotransitive ? (os_le ? of_ordered_set);
+   (*CSC: qui c'era un ? al posto di of_field *)
+   of_ordered_field_properties:> is_ordered_field_ch0 of_field (os_le ? of_ordered_set)
  }.
 
-interpretation "Ordered field le" 'leq a b =
- (cic:/matita/ordered_fields_ch0/of_le.con _ a b).
- 
-definition lt \def λF:ordered_field_ch0.λa,b:F.a ≤ b ∧ a ≠ b.
+(*theorem ordered_set_of_ordered_field_ch0:
+ ∀F:ordered_field_ch0.ordered_set F.
+ intros;
+ apply mk_ordered_set;
+  [ apply (mk_pre_ordered_set ? (of_le F))
+  | apply mk_is_order_relation;
+     [ apply (of_reflexive F)
+     | apply antisimmetric_to_cotransitive_to_transitive;
+       [ apply (of_antisimmetric F)
+       | apply (of_cotransitive F)
+       ]
+     | apply (of_antisimmetric F)
+     ]
+  ].
+qed.
 
-interpretation "Ordered field lt" 'lt a b =
- (cic:/matita/ordered_fields_ch0/lt.con _ a b).
+coercion cic:/matita/ordered_fields_ch0/ordered_set_of_ordered_field_ch0.con.
+*)
 
-lemma le_zero_x_to_le_opp_x_zero: ∀F:ordered_field_ch0.∀x:F. 0 ≤ x → -x ≤ 0.
+(*interpretation "Ordered field le" 'leq a b =
+ (cic:/matita/ordered_fields_ch0/of_le.con _ a b).
+ *)
+
+(*CSC: qua c'era uno zero*)
+lemma le_zero_x_to_le_opp_x_zero: ∀F:ordered_field_ch0.∀x:F.(zero F) ≤ x → -x ≤ 0.
 intros;
  generalize in match (of_plus_compat ? ? F ? ? (-x) H); intro;
  rewrite > zero_neutral in H1;
  rewrite > plus_comm in H1;
  rewrite > opp_inverse in H1;
- assumption.
+ (*assumption*)apply H1.
 qed.
 
-lemma le_x_zero_to_le_zero_opp_x: ∀F:ordered_field_ch0.∀x:F. x ≤ 0 → 0 ≤ -x.
+(*CSC: qua c'era uno zero*)
+lemma le_x_zero_to_le_zero_opp_x: ∀F:ordered_field_ch0.∀x:F. x ≤ 0 → (zero F) ≤ -x.
  intros;
  generalize in match (of_plus_compat ? ? F ? ? (-x) H); intro;
  rewrite > zero_neutral in H1;
  rewrite > plus_comm in H1;
  rewrite > opp_inverse in H1;
- assumption.
+ (*assumption.*) apply H1.
 qed.
 
 (*
@@ -68,7 +94,52 @@ lemma not_eq_x_zero_to_lt_zero_mult_x_x:
     generalize in match (of_mult_compat ? ? ? ? ? ? ? ?  F ? ? H2 H2); intro;
 *)  
 
+axiom lt_zero_to_lt_inv_zero:
+ ∀F:ordered_field_ch0.∀x:F.∀p:x≠0. lt ? F 0 x → lt ? F 0 (inv ? x p).
+
+alias symbol "lt" = "natural 'less than'".
+
 (* The ordering is not necessary. *)
 axiom not_eq_sum_field_zero: ∀F:ordered_field_ch0.∀n. O<n → sum_field F n ≠ 0.
+axiom le_zero_sum_field: ∀F:ordered_field_ch0.∀n. O<n → lt ? F 0 (sum_field F n).
 
+axiom lt_zero_to_le_inv_zero:
+ ∀F:ordered_field_ch0.∀n:nat.∀p:sum_field F n ≠ 0. os_le ? F 0 (inv ? (sum_field ? n) p).
+
+definition tends_to : ∀F:ordered_field_ch0.∀f:nat→F.∀l:F.Prop.
+ apply
+  (λF:ordered_field_ch0.λf:nat → F.λl:F.
+    ∀n:nat.∃m:nat.∀j:nat. le m j →
+     l - (inv F (sum_field ? (S n)) ?) ≤ f j ∧
+     f j ≤ l + (inv F (sum_field ? (S n)) ?));
+ apply not_eq_sum_field_zero;
+ unfold;
+ auto new.
+qed.
+
+(*
+definition is_cauchy_seq ≝
+ λF:ordered_field_ch0.λf:nat→F.
+  ∀eps:F. 0 < eps →
+   ∃n:nat.∀M. n ≤ M →
+    -eps ≤ f M - f n ∧ f M - f n ≤ eps.
+*)
+
+
+
+definition is_cauchy_seq : ∀F:ordered_field_ch0.∀f:nat→F.Prop.
+ apply
+  (λF:ordered_field_ch0.λf:nat→F.
+    ∀m:nat.
+     ∃n:nat.∀N. le n N →
+      -(inv ? (sum_field F (S m)) ?) ≤ f N - f n ∧
+      f N - f n ≤ inv ? (sum_field F (S m)) ?);
+ apply not_eq_sum_field_zero;
+ unfold;
+ auto.
+qed.
 
+definition is_complete ≝
+ λF:ordered_field_ch0.
+  ∀f:nat→F. is_cauchy_seq ? f →
+   ex F (λl:F. tends_to ? f l).
\ No newline at end of file