From 835f6498543d1f20cb02d134c1b22be7d622420e Mon Sep 17 00:00:00 2001
From: Claudio Sacerdoti Coen <claudio.sacerdoticoen@unibo.it>
Date: Thu, 6 Aug 2009 10:08:45 +0000
Subject: [PATCH] Setoid rewriting as unification hinting. Does not work
 recursively yet. (Why??)

---
 .../software/matita/nlibrary/sets/setoids1.ma |   4 +-
 helm/software/matita/nlibrary/sets/sets.ma    | 153 +++++++++++-------
 2 files changed, 94 insertions(+), 63 deletions(-)

diff --git a/helm/software/matita/nlibrary/sets/setoids1.ma b/helm/software/matita/nlibrary/sets/setoids1.ma
index bae7f549e..85038ab16 100644
--- a/helm/software/matita/nlibrary/sets/setoids1.ma
+++ b/helm/software/matita/nlibrary/sets/setoids1.ma
@@ -30,8 +30,8 @@ ndefinition setoid1_of_setoid: setoid → setoid1.
     | napply trans]##]
 nqed.
 
-ncoercion setoid1_of_setoid : ∀s:setoid. setoid1 ≝ setoid1_of_setoid
- on _s: setoid to setoid1.
+(*ncoercion setoid1_of_setoid : ∀s:setoid. setoid1 ≝ setoid1_of_setoid
+ on _s: setoid to setoid1.*)
 (*prefer coercion Type_OF_setoid.*)
 
 interpretation "setoid1 eq" 'eq t x y = (eq_rel1 ? (eq1 t) x y).
diff --git a/helm/software/matita/nlibrary/sets/sets.ma b/helm/software/matita/nlibrary/sets/sets.ma
index f4b924dcc..5ec6f42a8 100644
--- a/helm/software/matita/nlibrary/sets/sets.ma
+++ b/helm/software/matita/nlibrary/sets/sets.ma
@@ -12,94 +12,125 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "logic/cprop.ma".
+(******************* SETS OVER TYPES *****************)
 
-nrecord powerset (A: setoid) : Type[1] ≝ { mem_op:> unary_morphism1 A CPROP }.
+include "logic/connectives.ma".
 
-interpretation "powerset" 'powerset A = (powerset A).
+nrecord powerclass (A: Type[0]) : Type[1] ≝ { mem: A → CProp[0] }.
 
-interpretation "subset construction" 'subset \eta.x =
- (mk_powerset ? (mk_unary_morphism1 ? CPROP x ?)).
+interpretation "mem" 'mem a S = (mem ? S a).
+interpretation "powerclass" 'powerset A = (powerclass A).
+interpretation "subset construction" 'subset \eta.x = (mk_powerclass ? x).
 
-interpretation "mem" 'mem a S = (mem_op ? S a).
+ndefinition subseteq ≝ λA.λU,V.∀a:A. a ∈ U → a ∈ V.
+interpretation "subseteq" 'subseteq U V = (subseteq ? U V).
 
-ndefinition subseteq ≝ λA:setoid.λU,V.∀a:A. a ∈ U → a ∈ V.
+ndefinition overlaps ≝ λA.λU,V.∃x:A.x ∈ U ∧ x ∈ V.
+interpretation "overlaps" 'overlaps U V = (overlaps ? U V).
 
-interpretation "subseteq" 'subseteq U V = (subseteq ? U V).
+ndefinition intersect ≝ λA.λU,V:Ω \sup A.{ x | x ∈ U ∧ x ∈ V }.
+interpretation "intersect" 'intersects U V = (intersect ? U V).
 
-ntheorem subseteq_refl: ∀A.∀S:Ω \sup A.S ⊆ S.
- #A; #S; #x; #H; nassumption;
-nqed.
+ndefinition union ≝ λA.λU,V:Ω \sup A.{ x | x ∈ U ∨ x ∈ V }.
+interpretation "union" 'union U V = (union ? U V).
 
-ntheorem subseteq_trans: ∀A.∀S1,S2,S3: Ω \sup A. S1 ⊆ S2 → S2 ⊆ S3 → S1 ⊆ S3.
- #A; #S1; #S2; #S3; #H12; #H23; #x; #H;
- napply H23; napply H12; nassumption;
+nlemma subseteq_refl: ∀A.∀S: Ω \sup A. S ⊆ S.
+ #A; #S; #x; #H; nassumption.
 nqed.
 
-ndefinition powerset_setoid1: setoid → setoid1.
- #S; napply mk_setoid1
-  [ napply (Ω \sup S)
-  | napply mk_equivalence_relation1
-     [ #A; #B; napply (∀x. iff (x ∈ A) (x ∈ B))
-     | nwhd; #x; #x0; napply mk_iff; #H; nassumption
-     | nwhd; #x; #y; #H; #A; napply mk_iff; #K
-        [ napply (fi ?? (H ?)) | napply (if ?? (H ?)) ]
-        nassumption
-     | nwhd; #A; #B; #C; #H1; #H2; #H3; napply mk_iff; #H4
-        [ napply (if ?? (H2 ?)); napply (if ?? (H1 ?)); nassumption
-        | napply (fi ?? (H1 ?)); napply (fi ?? (H2 ?)); nassumption]##]
+nlemma subseteq_trans: ∀A.∀S,T,U: Ω \sup A. S ⊆ T → T ⊆ U → S ⊆ U.
+ #A; #S; #T; #U; #H1; #H2; #x; #P; napply H2; napply H1; nassumption.
 nqed.
 
-unification hint 0 (∀A.(λx,y.True) (Ω \sup A) (carr1 (powerset_setoid1 A))).
+include "properties/relations1.ma".
 
-ndefinition mem: ∀A:setoid. binary_morphism1 A (powerset_setoid1 A) CPROP.
- #A; napply mk_binary_morphism1
-  [ napply (λa.λA.a ∈ A)
-  | #a; #a'; #B; #B'; #Ha; #HB; napply mk_iff; #H
-     [ napply (. (†Ha^-1)); (* CSC: notation for ∈ not working *)
-       napply (if ?? (HB ?)); nassumption
-     | napply (. (†Ha)); napply (fi ?? (HB ?)); nassumption]##]
-nqed.
+ndefinition seteq: ∀A. equivalence_relation1 (Ω \sup A).
+ #A; napply mk_equivalence_relation1
+  [ napply (λS,S'. S ⊆ S' ∧ S' ⊆ S)
+  | #S; napply conj; napply subseteq_refl
+  | #S; #S'; *; #H1; #H2; napply conj; nassumption
+  | #S; #T; #U; *; #H1; #H2; *; #H3; #H4; napply conj; napply subseteq_trans;
+     ##[##2,5: nassumption |##1,4: ##skip |##*: nassumption]##]
+nqed. 
 
-unification hint 0 (∀A,x,S. (λx,y.True) (mem_op A x S) (fun21 ??? (mem A) S x)).
+include "sets/setoids1.ma".
 
-ndefinition overlaps ≝ λA.λU,V:Ω \sup A.∃x:A.x ∈ U ∧ x ∈ V.
+ndefinition powerclass_setoid: Type[0] → setoid1.
+ #A; napply mk_setoid1
+  [ napply (Ω \sup A)
+  | napply seteq ]
+nqed. 
 
-interpretation "overlaps" 'overlaps U V = (overlaps ? U V).
+(************ SETS OVER SETOIDS ********************)
 
-ndefinition intersects ≝ λA:Type[0].λU,V:A → CProp[0]. λx. U x ∧ V x.
+include "logic/cprop.ma".
 
-interpretation "intersects" 'intersects U V = (intersects ? U V).
+nrecord qpowerclass (A: setoid) : Type[1] ≝
+ { pc:> Ω \sup A;
+   mem_ok': ∀x,x':A. x=x' → (x ∈ pc) = (x' ∈ pc) 
+ }.
+
+ndefinition qseteq: ∀A. equivalence_relation1 (qpowerclass A).
+ #A; napply mk_equivalence_relation1
+  [ napply (λS,S':qpowerclass A. eq_rel1 ? (eq1 (powerclass_setoid A)) S S')
+  | #S; napply (refl1 ? (seteq A))
+  | #S; #S'; napply (sym1 ? (seteq A))
+  | #S; #T; #U; napply (trans1 ? (seteq A))]
+nqed.
 
-(* dovrebbe essere un binario? *)
-ndefinition intersects_ok: ∀A. Ω \sup A → Ω \sup A → Ω \sup A.
- #A; #U; #V; napply mk_powerset; napply mk_unary_morphism1
-  [ napply (intersects ? (mem_op ? U) (mem_op ? V))
-  | #a; #a'; #H; napply mk_iff; *; #H1; #H2
-    [ nwhd; napply (. ((H^-1‡#)‡(H^-1‡#))); nwhd; napply conj; nassumption
-    | nwhd; napply (. ((H‡#)‡(H‡#))); nwhd; napply conj; nassumption]
+ndefinition qpowerclass_setoid: setoid → setoid1.
+ #A; napply mk_setoid1
+  [ napply (qpowerclass A)
+  | napply (qseteq A) ]
 nqed.
 
-unification hint 0 (∀A.∀U,V: Ω \sup A.∀w.(λx,y.True)
- (intersects A U V w) (fun11 ?? (mem_op ? (intersects_ok A U V)) w)).
+unification hint 0 (∀A. (λx,y.True) (carr1 (qpowerclass_setoid A)) (qpowerclass A)).
+ncoercion qpowerclass_hint: ∀A: setoid. ∀S: qpowerclass_setoid A. Ω \sup A ≝ λA.λS.S
+ on _S: (carr1 (qpowerclass_setoid ?)) to (Ω \sup ?). 
 
-nlemma test: ∀A. ∀U,V: Ω \sup A. ∀x,x':A. x=x' → (U ∩ V) x → (U ∩ V) x'.
- #A; #U; #V; #x; #x'; #H; #p;
- nwhd in ⊢ (? ? % % ?);
- (* l'unification hint non funziona *)
-  nchange with (? ∈ (intersects_ok ? ? ?));
-  napply (. (†H^-1));
-  nassumption.
+nlemma mem_ok: ∀A. binary_morphism1 (setoid1_of_setoid A) (qpowerclass_setoid A) CPROP.
+ #A; napply mk_binary_morphism1
+  [ napply (λx.λS: qpowerclass_setoid A. x ∈ S) (* CSC: ??? *)
+  | #a; #a'; #b; #b'; #Ha; #Hb; (* CSC: qui *; non funziona *)
+    nwhd; nwhd in ⊢ (? (? % ??) (? % ??)); napply mk_iff; #H
+     [ ncases Hb; #Hb1; #_; napply Hb1; napply (. (mem_ok' …))
+        [ nassumption | napply Ha^-1 | ##skip ]
+   ##| ncases Hb; #_; #Hb2; napply Hb2; napply (. (mem_ok' …))
+        [ nassumption | napply Ha | ##skip ]##]
 nqed.
 
-(*
-ndefinition union ≝ λA.λU,V:Ω \sup A. {x | x ∈ U ∨ x ∈ V }.
+unification hint 0 (∀A,x,S. (λx,y.True) (fun21 ??? (mem_ok A) x S) (mem A S x)).
+  
+nlemma subseteq_ok: ∀A. binary_morphism1 (qpowerclass_setoid A) (qpowerclass_setoid A) CPROP.
+ #A; napply mk_binary_morphism1
+  [ napply (λS,S': qpowerclass_setoid ?. S ⊆ S')
+  | #a; #a'; #b; #b'; *; #Ha1; #Ha2; *; #Hb1; #Hb2; napply mk_iff; #H
+     [ napply (subseteq_trans … a' a) (* anche qui, perche' serve a'? *)
+        [ nassumption | napply (subseteq_trans … a b); nassumption ]
+   ##| napply (subseteq_trans … a a') (* anche qui, perche' serve a'? *)
+        [ nassumption | napply (subseteq_trans … a' b'); nassumption ] ##]
+nqed.
 
-interpretation "union" 'union U V = (union ? U V).
+nlemma intersect_ok: ∀A. binary_morphism1 (qpowerclass_setoid A) (qpowerclass_setoid A) (qpowerclass_setoid A).
+ #A; napply mk_binary_morphism1
+  [ #S; #S'; napply mk_qpowerclass
+     [ napply (S ∩ S')
+     | #a; #a'; #Ha; nwhd in ⊢ (? ? ? % %); napply mk_iff; *; #H1; #H2; napply conj
+        [##1,2: napply (. (mem_ok' …)^-1) [##3,6: nassumption |##1,4: nassumption |##*: ##skip]
+      ##|##3,4: napply (. (mem_ok' …)) [##2,5: nassumption |##1,4: nassumption |##*: ##skip]##]##]
+ ##| #a; #a'; #b; #b'; #Ha; #Hb; nwhd; napply conj; #x; nwhd in ⊢ (% → %); #H
+      [ napply (. ((#‡Ha^-1)‡(#‡Hb^-1))); nassumption
+      | napply (. ((#‡Ha)‡(#‡Hb))); nassumption ]##]
+nqed.
 
-ndefinition singleton ≝ λA:setoid.λa:A.{b | a=b}.
+unification hint 0 (∀A.∀U,V.(λx,y.True) (fun21 ??? (intersect_ok A) U V) (intersect A U V)).
 
-interpretation "singleton" 'singl a = (singleton ? a).*)
+nlemma test: ∀A:setoid. ∀U,V:qpowerclass A. ∀x,x':setoid1_of_setoid A. x=x' → x ∈ U ∩ V → x' ∈ U ∩ V.
+ #A; #U; #V; #x; #x'; #H; #p;
+  (* CSC: senza la change non funziona! *)
+  nchange with (x' ∈ (fun21 ??? (intersect_ok A) U V));
+  napply (. (H^-1‡#)); nassumption.
+nqed.
 
 (*
 (* qui non funziona una cippa *)
-- 
2.39.2