1 (**************************************************************************)
4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
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15 include "sequence.ma".
16 include "ordered_set.ma".
19 definition upper_bound ≝ λO:ordered_set.λa:sequence O.λu:O.∀n:nat.a n ≤ u.
21 definition strong_sup ≝
22 λO:ordered_set.λs:sequence O.λx.upper_bound ? s x ∧ (∀y:O.x ≰ y → ∃n.s n ≰ y).
24 definition increasing ≝ λO:ordered_set.λa:sequence O.∀n:nat.a n ≤ a (S n).
26 notation < "x \nbsp 'is_upper_bound' \nbsp s" non associative with precedence 50
27 for @{'upper_bound $s $x}.
28 notation < "s \nbsp 'is_increasing'" non associative with precedence 50
29 for @{'increasing $s}.
30 notation < "x \nbsp 'is_strong_sup' \nbsp s" non associative with precedence 50
31 for @{'strong_sup $s $x}.
33 notation > "x 'is_upper_bound' s" non associative with precedence 50
34 for @{'upper_bound $s $x}.
35 notation > "s 'is_increasing'" non associative with precedence 50
36 for @{'increasing $s}.
37 notation > "x 'is_strong_sup' s" non associative with precedence 50
38 for @{'strong_sup $s $x}.
40 interpretation "Ordered set upper bound" 'upper_bound s x =
41 (cic:/matita/dama/supremum/upper_bound.con _ s x).
42 interpretation "Ordered set increasing" 'increasing s =
43 (cic:/matita/dama/supremum/increasing.con _ s).
44 interpretation "Ordered set strong sup" 'strong_sup s x =
45 (cic:/matita/dama/supremum/strong_sup.con _ s x).
47 include "bishop_set.ma".
50 ∀O:ordered_set.∀s:sequence O.∀t1,t2:O.
51 t1 is_upper_bound s → t2 is_upper_bound s → t1 ≈ t2.
52 intros (O s t1 t2 Ht1 Ht2); apply le_le_eq; cases Ht1; cases Ht2;