commit by user andrea

diff --git a/weblib/tutorial/chapter3.ma b/weblib/tutorial/chapter3.ma
index 14f7aaaa7b982b5d6eb49d4c912fe948bd7572fb..bd5d17297c4f57c33c02e124b734f68ba095fbd0 100644 (file)
--- a/weblib/tutorial/chapter3.ma
+++ b/weblib/tutorial/chapter3.ma
@@ -1,16 +1,4 @@
-(*
-    ||M||  This file is part of HELM, an Hypertextual, Electronic        
-    ||A||  Library of Mathematics, developed at the Computer Science     
-    ||T||  Department of the University of Bologna, Italy.                     
-    ||I||                                                                 
-    ||T||  
-    ||A||  
-    \   /  This file is distributed under the terms of the       
-     \ /   GNU General Public License Version 2   
-      V_______________________________________________________________ *)
-
 include "basics/bool.ma".
-(* include "arithmetics/nat.ma". *)
 
 inductive list (A:Type[0]) : Type[0] :=
   | nil: list A
@@ -31,78 +19,66 @@ notation "hvbox(l1 break @ l2)"
 interpretation "nil" 'nil = (nil ?).
 interpretation "cons" 'cons hd tl = (cons ? hd tl).
 
-definition not_nil: ∀A:Type[0].\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A → Prop ≝
- λA.λl.match l with [ nil ⇒ \ 5a href="cic:/matita/basics/logic/True.ind(1,0,0)"\ 6True\ 5/a\ 6 | cons hd tl ⇒ \ 5a href="cic:/matita/basics/logic/False.ind(1,0,0)"\ 6False\ 5/a\ 6 ].
+definition not_nil: ∀A:Type[0].\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A → Prop ≝
+ λA.λl.match l with [ nil ⇒ \ 5a href="cic:/matita/basics/logic/True.ind(1,0,0)"\ 6True\ 5/a\ 6| cons hd tl ⇒ \ 5a href="cic:/matita/basics/logic/False.ind(1,0,0)"\ 6False\ 5/a\ 6].
 
 theorem nil_cons:
-  ∀A:Type[0].∀l:\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.∀a:A. a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l \ 5a title="leibnitz's non-equality" href="cic:/fakeuri.def(1)"\ 6≠\ 5/a\ 6 \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6].
-  #A #l #a @\ 5a href="cic:/matita/basics/logic/Not.con(0,1,1)"\ 6nmk\ 5/a\ 6 #Heq (change with (\ 5a href="cic:/matita/basics/list/not_nil.def(1)"\ 6not_nil\ 5/a\ 6 ? (a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l))) >Heq //
+  ∀A:Type[0].∀l:\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.∀a:A. a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l \ 5a title="leibnitz's non-equality" href="cic:/fakeuri.def(1)"\ 6≠\ 5/a\ 6 \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6].
+  #A #l #a @\ 5a href="cic:/matita/basics/logic/Not.con(0,1,1)"\ 6nmk\ 5/a\ 6 #Heq (change with (\ 5a href="cic:/matita/tutorial/chapter3/not_nil.def(1)"\ 6not_nil\ 5/a\ 6 ? (a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l))) >Heq //
 qed.
 
-(*
-let rec id_list A (l: list A) on l :=
-  match l with
-  [ nil => []
-  | (cons hd tl) => hd :: id_list A tl ]. *)
-
-let rec append A (l1: \ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) l2 on l1 ≝ 
+let rec append A (l1: \ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) l2 on l1 ≝ 
   match l1 with
   [ nil ⇒  l2
   | cons hd tl ⇒  hd \ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6: append A tl l2 ].
 
-definition hd ≝ λA.λl: \ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.λd:A.
+definition hd ≝ λA.λl: \ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.λd:A.
   match l with [ nil ⇒ d | cons a _ ⇒ a].
 
-definition tail ≝  λA.λl: \ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.
+definition tail ≝  λA.λl: \ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.
   match l with [ nil ⇒  \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] | cons hd tl ⇒  tl].
 
 interpretation "append" 'append l1 l2 = (append ? l1 l2).
 
-theorem append_nil: ∀A.∀l:\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.l \ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6 \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 l.
+theorem append_nil: ∀A.∀l:\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.l \ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6 \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 l.
 #A #l (elim l) normalize // qed.
 
 theorem associative_append: 
- ∀A.\ 5a href="cic:/matita/basics/relations/associative.def(1)"\ 6associative\ 5/a\ 6 (\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) (\ 5a href="cic:/matita/basics/list/append.fix(0,1,1)"\ 6append\ 5/a\ 6 A).
+ ∀A.\ 5a href="cic:/matita/basics/relations/associative.def(1)"\ 6associative\ 5/a\ 6 (\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) (\ 5a href="cic:/matita/tutorial/chapter3/append.fix(0,1,1)"\ 6append\ 5/a\ 6 A).
 #A #l1 #l2 #l3 (elim l1) normalize // qed.
 
-(* deleterio per auto 
-ntheorem cons_append_commute:
-  ∀A:Type.∀l1,l2:list A.∀a:A.
-    a :: (l1 @ l2) = (a :: l1) @ l2.
-//; nqed. *)
-
-theorem append_cons:∀A.∀a:A.∀l,l1.l\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6(a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l1)\ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6(l\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6a])\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6l1.
-/2/ qed.
+(* qualcosa di strano qui theorem append_cons:∀A.∀a:A.∀l,l1: \ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.l\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6(a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l1)\ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 (l \ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6 \ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6a]) \ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6 l1.
+/2/ qed. *)
 
-theorem nil_append_elim: ∀A.∀l1,l2: \ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.∀P:?→?→Prop. 
-  l1\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6l2\ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6\ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] → P (\ 5a href="cic:/matita/basics/list/list.con(0,1,1)"\ 6nil\ 5/a\ 6 A) (\ 5a href="cic:/matita/basics/list/list.con(0,1,1)"\ 6nil\ 5/a\ 6 A) → P l1 l2.
+theorem nil_append_elim: ∀A.∀l1,l2: \ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.∀P:?→?→Prop. 
+  l1\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6l2\ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6\ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] → P \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] → P l1 l2.
 #A #l1 #l2 #P (cases l1) normalize //
 #a #l3 #heq destruct
 qed.
 
-theorem nil_to_nil:  ∀A.∀l1,l2:\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A.
+theorem nil_to_nil:  ∀A.∀l1,l2:\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 \ 5span style="text-decoration: underline;"\ 6\ 5/span\ 6A.
   l1\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6l2 \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] → l1 \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] \ 5a title="logical and" href="cic:/fakeuri.def(1)"\ 6∧\ 5/a\ 6 l2 \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6].
-#A #l1 #l2 #isnil @(\ 5a href="cic:/matita/basics/list/nil_append_elim.def(3)"\ 6nil_append_elim\ 5/a\ 6 A l1 l2) /2/
+#A #l1 #l2 #isnil @(\ 5a href="cic:/matita/tutorial/chapter3/nil_append_elim.def(3)"\ 6nil_append_elim\ 5/a\ 6 A l1 l2) /2/
 qed.
 
 (* iterators *)
 
-let rec map (A,B:Type[0]) (f: A → B) (l:\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) on l: \ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 B ≝
- match l with [ nil ⇒ \ 5a href="cic:/matita/basics/list/list.con(0,1,1)"\ 6nil\ 5/a\ 6 ? | cons x tl ⇒ f x \ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6: (map A B f tl)].
+let rec map (A,B:Type[0]) (f: A → B) (l:\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) on l: \ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 B ≝
+ match l with [ nil ⇒ \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6] | cons x tl ⇒ f x \ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6: (map A B f tl)].
   
-let rec foldr (A,B:Type[0]) (f:A → B → B) (b:B) (l:\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) on l :B ≝  
+let rec foldr (A,B:Type[0]) (f:A → B → B) (b:B) (l:\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 A) on l :B ≝  
  match l with [ nil ⇒ b | cons a l ⇒ f a (foldr A B f b l)].
  
 definition filter ≝ 
   λT.λp:T → \ 5a href="cic:/matita/basics/bool/bool.ind(1,0,0)"\ 6bool\ 5/a\ 6.
-  \ 5a href="cic:/matita/basics/list/foldr.fix(0,4,1)"\ 6foldr\ 5/a\ 6 T (\ 5a href="cic:/matita/basics/list/list.ind(1,0,1)"\ 6list\ 5/a\ 6 T) (λx,l0.\ 5a href="cic:/matita/basics/bool/if_then_else.def(1)"\ 6if_then_else\ 5/a\ 6 ? (p x) (x\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l0) l0) (\ 5a href="cic:/matita/basics/list/list.con(0,1,1)"\ 6nil\ 5/a\ 6 T).
+  \ 5a href="cic:/matita/tutorial/chapter3/foldr.fix(0,4,1)"\ 6foldr\ 5/a\ 6 T (\ 5a href="cic:/matita/tutorial/chapter3/list.ind(1,0,1)"\ 6list\ 5/a\ 6 T) (λx,l0.\ 5a href="cic:/matita/basics/bool/if_then_else.def(1)"\ 6if_then_else\ 5/a\ 6 ? (p x) (x\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l0) l0) \ 5a title="nil" href="cic:/fakeuri.def(1)"\ 6[\ 5/a\ 6].
 
 lemma filter_true : ∀A,l,a,p. p a \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a href="cic:/matita/basics/bool/bool.con(0,1,0)"\ 6true\ 5/a\ 6 → 
-  \ 5a href="cic:/matita/basics/list/filter.def(2)"\ 6filter\ 5/a\ 6 A p (a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l) \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 a \ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6: \ 5a href="cic:/matita/basics/list/filter.def(2)"\ 6filter\ 5/a\ 6 A p l.
-#A #l #a #p #pa (elim l) normalize >pa normalize // qed.
+  \ 5a href="cic:/matita/tutorial/chapter3/filter.def(2)"\ 6filter\ 5/a\ 6 A p (a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l) \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 a \ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6: \ 5a href="cic:/matita/tutorial/chapter3/filter.def(2)"\ 6filter\ 5/a\ 6 A p l.
+#A #l #a #p #pa (elim l) normalize >pa // qed.
 
 lemma filter_false : ∀A,l,a,p. p a \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a href="cic:/matita/basics/bool/bool.con(0,2,0)"\ 6false\ 5/a\ 6 → 
-  \ 5a href="cic:/matita/basics/list/filter.def(2)"\ 6filter\ 5/a\ 6 A p (a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l) \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a href="cic:/matita/basics/list/filter.def(2)"\ 6filter\ 5/a\ 6 A p l.
+  \ 5a href="cic:/matita/tutorial/chapter3/filter.def(2)"\ 6filter\ 5/a\ 6 A p (a\ 5a title="cons" href="cic:/fakeuri.def(1)"\ 6:\ 5/a\ 6:l) \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a href="cic:/matita/tutorial/chapter3/filter.def(2)"\ 6filter\ 5/a\ 6 A p l.
 #A #l #a #p #pa (elim l) normalize >pa normalize // qed.
 
 theorem eq_map : ∀A,B,f,g,l. (∀x.f x \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 g x) → \ 5a href="cic:/matita/basics/list/map.fix(0,3,1)"\ 6map\ 5/a\ 6 A B f l \ 5a title="leibnitz's equality" href="cic:/fakeuri.def(1)"\ 6=\ 5/a\ 6 \ 5a href="cic:/matita/basics/list/map.fix(0,3,1)"\ 6map\ 5/a\ 6 A B g l.
@@ -122,9 +98,6 @@ let rec length (A:Type[0]) (l:list A) on l ≝
     [ nil ⇒ 0
     | cons a tl ⇒ S (length A tl)].
 
-notation "|M|" non associative with precedence 60 for @{'norm $M}.
-interpretation "norm" 'norm l = (length ? l).
-
 let rec nth n (A:Type[0]) (l:list A) (d:A)  ≝  
   match n with
     [O ⇒ hd A l d
@@ -182,5 +155,4 @@ theorem fold_sum: ∀A,B. ∀I,J:\ 5a href="cic:/matita/basics/list/list.ind(1,0,1
     \ 5a title="\fold" href="cic:/fakeuri.def(1)"\ 6\fold\ 5/a\ 6[op,nil]_{i∈(I\ 5a title="append" href="cic:/fakeuri.def(1)"\ 6@\ 5/a\ 6J)} (f i).
 #A #B #I #J #nil #op #f (elim I) normalize 
   [>\ 5a href="cic:/matita/basics/list/nill.fix(0,2,2)"\ 6nill\ 5/a\ 6 //|#a #tl #Hind <\ 5a href="cic:/matita/basics/list/assoc.fix(0,2,2)"\ 6assoc\ 5/a\ 6 //]
-qed.
-
+qed.
\ No newline at end of file