Change (or better define) the order of hints premises.

[helm.git] / helm / software / matita / nlibrary / hints_declaration.ma

diff --git a/helm/software/matita/nlibrary/hints_declaration.ma b/helm/software/matita/nlibrary/hints_declaration.ma
index b826d2e767dda6a0d3adae1b551da9e84c9ae301..99aca7fa6e79fe01a6f086cded9bbc146b309a9a 100644 (file)
--- a/helm/software/matita/nlibrary/hints_declaration.ma
+++ b/helm/software/matita/nlibrary/hints_declaration.ma
@@ -34,9 +34,13 @@ With unidoce and some ASCII art it looks like the following:
  (*---------------------*) ⊢
          T1 ≡ T2       
 
+The order of premises is relevant, since they are processed in order
+(left to right).
+
 *)
    
-notation > "≔ (list0 ( ident x : T ) sep ,) opt (; (list1 (ident U ≟ term 90 V ) sep ,)) ⊢ term 19 Px ≡ term 19 Py"
+(* it seems unbelivable, but it works! *)
+notation > "≔ (list0 ( (list1 (ident x) sep , ) opt (: T) ) sep ,) opt (; (list1 (ident U ≟ term 19 V ) sep ,)) ⊢ term 19 Px ≡ term 19 Py"
   with precedence 90
   for @{ ${ fold right 
                @{ ${ default 
@@ -46,16 +50,20 @@ notation > "≔ (list0 ( ident x : T ) sep ,) opt (; (list1 (ident U ≟ term 90
                     @{ 'hint_decl $Px $Py } 
                  }
                } 
-               rec acc @{ ∀${ident x}:$T.$acc } } }.
+               rec acc @{ 
+                 ${ fold right @{ $acc } rec acc2 
+                      @{ ∀${ident x}:${ default @{ $T } @{ ? } }.$acc2 } } 
+               }
+       }}.
 
 include "logic/pts.ma".
 
 ndefinition hint_declaration_Type0  ≝  λA:Type[0] .λa,b:A.Prop.
 ndefinition hint_declaration_Type1  ≝  λA:Type[1].λa,b:A.Prop.
-ndefinition hint_declaration_Type2  ≝  λa,b:Type[1].Prop.
+ndefinition hint_declaration_Type2  ≝  λa,b:Type[2].Prop.
 ndefinition hint_declaration_CProp0 ≝  λA:CProp[0].λa,b:A.Prop.
 ndefinition hint_declaration_CProp1 ≝  λA:CProp[1].λa,b:A.Prop.
-ndefinition hint_declaration_CProp2 ≝  λa,b:CProp[1].Prop.
+ndefinition hint_declaration_CProp2 ≝  λa,b:CProp[2].Prop.
   
 interpretation "hint_decl_Type2"  'hint_decl a b = (hint_declaration_Type2 a b).
 interpretation "hint_decl_CProp2" 'hint_decl a b = (hint_declaration_CProp2 a b).
@@ -64,12 +72,35 @@ interpretation "hint_decl_CProp1" 'hint_decl a b = (hint_declaration_CProp1 ? a
 interpretation "hint_decl_CProp0" 'hint_decl a b = (hint_declaration_CProp0 ? a b).
 interpretation "hint_decl_Type0"  'hint_decl a b = (hint_declaration_Type0 ? a b).
 
-(* little test 
-naxiom A : Type[0].
-naxiom C : A → A → Type[0].
-ndefinition D ≝ C.               
-alias symbol "hint_decl" = "hint_decl_Type1".
-unification hint 0 ≔ 
-  X : A, Y : A ;  Z ≟ X, W ≟ Y ⊢ C X Y ≡ D Z W.
-  
-*)  
+(* Non uniform coercions support *)
+nrecord lock2 (S : Type[2]) (s : S) : Type[3] ≝ {
+  force2 : Type[2];
+  lift2  : force2
+}.
+
+nrecord lock1 (S : Type[1]) (s : S) : Type[2] ≝ {
+  force1 : Type[1];
+  lift1  : force1
+}.
+
+ncoercion lift1 : ∀S:Type[1].∀s:S.∀l:lock1 S s. force1 S s l ≝ lift1 
+ on s : ? to force1 ???.
+
+ncoercion lift2 : ∀S:Type[2].∀s:S.∀l:lock2 S s. force2 S s l ≝ lift2
+ on s : ? to force2 ???.
+
+(* Example of a non uniform coercion declaration 
+   
+     Type[0]              setoid
+                >--->     
+     MR                   R  
+
+   provided MR = carr R
+
+unification hint 0 ≔ R : setoid;
+   MR ≟ carr R, 
+   lock ≟ mk_lock1 Type[0] MR setoid R 
+(* ---------------------------------------- *) ⊢ 
+   setoid ≡ force1 ? MR lock.
+
+*)
\ No newline at end of file