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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
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11 (* v GNU General Public License Version 2 *)
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15 set "baseuri" "cic:/matita/formal_topology/".
16 include "logic/equality.ma".
20 axiom comp: S → S → S.
21 coercion cic:/matita/formal_topology/comp.con 1.
23 axiom comp_assoc: ∀A,B,C:S. A (B C) = (A B) C.
27 notation "1" with precedence 89
30 interpretation "Unit" 'unit = one.
32 axiom one_left: ∀A. 1 A = A.
33 axiom one_right: ∀A:S. A 1 = A.
36 axiom eps_idempotent: eps = eps eps.
38 notation "hvbox(A break ⊆ B)" with precedence 59
39 for @{ 'subseteq $A $B}.
41 interpretation "Subseteq" 'subseteq A B = (eq ? A (comp eps B)).
43 axiom leq_refl: ∀A. A ⊆ A.
44 axiom leq_antisym: ∀A,B. A ⊆ B → B ⊆ A → A=B.
45 axiom leq_tran: ∀A,B,C. A ⊆ B → B ⊆ C → A ⊆ C.
49 axiom i_contrattivita: i ⊆ 1.
50 axiom i_idempotenza: i i = i.
51 axiom i_monotonia: ∀A,B. A ⊆ B → i A ⊆ i B.
55 axiom c_espansivita: 1 ⊆ c.
56 axiom c_idempotenza: c c = c.
57 axiom c_monotonia: ∀A,B. A ⊆ B → c A ⊆ c B.
61 axiom m_antimonotonia: ∀A,B. A ⊆ B → m B ⊆ m A.
62 axiom m_saturazione: 1 ⊆ m m.
63 axiom m_puntofisso: m = m (m m).
65 theorem th1: c m ⊆ m i. intros; auto. qed.
66 theorem th2: ∀A. i (m A) ⊆ (m (c A)). intros; auto. qed.
67 theorem th3: ∀A. i A ⊆ (m (c (m A))). intros; auto. qed.
68 theorem th4: ∀A. c A ⊆ (m (i (m A))). intros; auto. qed.
70 theorem th5: ∀A. i (m A) = i (m (c A)). intros; auto. qed.
71 theorem th6: ∀A. m (i A) = c (m (i A)). intros; auto. qed.
73 theorem th7: ∀A. i (m (i A)) = i (s (i A)).