--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+include "dama/uniform.ma".
+include "dama/bishop_set_rewrite.ma".
+
+definition discrete_uniform_space_of_bishop_set:bishop_set → uniform_space.
+intro C; apply (mk_uniform_space C);
+[1: intro;
+ alias symbol "pi2" = "pair pi2".
+ alias symbol "pi1" = "pair pi1".
+ alias symbol "and" = "logical and".
+ apply (∃d:unit.∀n:C squareB.(\fst n ≈ \snd n → P n) ∧ (P n → \fst n ≈ \snd n));
+|2: intros 4 (U H x Hx); simplify in Hx;
+ cases H (_ H1); cases (H1 x); apply H2; apply Hx;
+|3: intros; cases H (_ PU); cases H1 (_ PV);
+ exists[apply (λx.U x ∧ V x)] split;
+ [1: exists[apply something] intro; cases (PU n); cases (PV n);
+ split; intros; try split;[apply H2;|apply H4] try assumption;
+ apply H3; cases H6; assumption;
+ |2: simplify; intros; assumption;]
+|4: intros; cases H (_ PU); exists [apply U] split;
+ [1: exists [apply something] intro n; cases (PU n);
+ split; intros; try split;[apply H1;|apply H2] assumption;
+ |2: intros 2 (x Hx); cases Hx; cases H1; clear H1;
+ cases (PU 〈(\fst x),x1〉); lapply (H4 H2) as H5; simplify in H5;
+ cases (PU 〈x1,(\snd x)〉); lapply (H7 H3) as H8; simplify in H8;
+ generalize in match H5; generalize in match H8;
+ generalize in match (PU x); clear H6 H7 H1 H4 H2 H3 H5 H8;
+ cases x; simplify; intros; cases H1; clear H1; apply H4;
+ apply (eq_trans ???? H3 H2);]
+|5: intros; cases H (_ H1); split; cases x;
+ [2: cases (H1 〈b,b1〉); intro; apply H2; cases (H1 〈b1,b〉);
+ lapply (H6 H4) as H7; apply eq_sym; apply H7;
+ |1: cases (H1 〈b1,b〉); intro; apply H2; cases (H1 〈b,b1〉);
+ lapply (H6 H4) as H7; apply eq_sym; apply H7;]]
+qed.