+++ /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 *)
-(* *)
-(**************************************************************************)
-
-set "baseuri" "cic:/matita/list/".
-include "logic/equality.ma".
-include "higher_order_defs/functions.ma".
-
-inductive list (A:Set) : Set :=
- | nil: list A
- | cons: A -> list A -> list A.
-
-notation "hvbox(hd break :: tl)"
- right associative with precedence 46
- for @{'cons $hd $tl}.
-
-notation "[ list0 x sep ; ]"
- non associative with precedence 90
- for ${fold right @'nil rec acc @{'cons $x $acc}}.
-
-notation "hvbox(l1 break @ l2)"
- right associative with precedence 47
- for @{'append $l1 $l2 }.
-
-interpretation "nil" 'nil = (cic:/matita/list/list.ind#xpointer(1/1/1) _).
-interpretation "cons" 'cons hd tl =
- (cic:/matita/list/list.ind#xpointer(1/1/2) _ hd tl).
-
-(* theorem test_notation: [O; S O; S (S O)] = O :: S O :: S (S O) :: []. *)
-
-theorem nil_cons:
- \forall A:Set.\forall l:list A.\forall a:A.
- a::l <> [].
- intros;
- unfold Not;
- intros;
- discriminate H.
-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: list A) l2 on l1 :=
- match l1 with
- [ nil => l2
- | (cons hd tl) => hd :: append A tl l2 ].
-
-definition tail := \lambda A:Set. \lambda l: list A.
- match l with
- [ nil => []
- | (cons hd tl) => tl].
-
-interpretation "append" 'append l1 l2 = (cic:/matita/list/append.con _ l1 l2).
-
-theorem append_nil: \forall A:Set.\forall l:list A.l @ [] = l.
- intros;
- elim l;
- [ reflexivity;
- | simplify;
- rewrite > H;
- reflexivity;
- ]
-qed.
-
-theorem associative_append: \forall A:Set.associative (list A) (append A).
- intros; unfold; intros;
- elim x;
- [ simplify;
- reflexivity;
- | simplify;
- rewrite > H;
- reflexivity;
- ]
-qed.
-
-theorem cons_append_commute:
- \forall A:Set.\forall l1,l2:list A.\forall a:A.
- a :: (l1 @ l2) = (a :: l1) @ l2.
- intros;
- reflexivity;
-qed.
-
-(*
-theorem nil_append_nil_both:
- \forall A:Set.\forall l1,l2:list A.
- l1 @ l2 = [] \to l1 = [] \land l2 = [].
-*)
-
-(*
-include "nat/nat.ma".
-
-theorem test_notation: [O; S O; S (S O)] = O :: S O :: S (S O) :: [].
-reflexivity.
-qed.
-
-theorem test_append: [O;O;O;O;O;O] = [O;O;O] @ [O;O] @ [O].
-simplify.
-reflexivity.
-qed.
-*)