| THIS IS A OLD CONTRIB. IT IS NO LONGER MAINTAINED ** |
Require Le.
Parameter List_Dom:Set.
Definition A := List_Dom.
Inductive list : Set := nil : list | cons : A -> list -> list.
Fixpoint app [l:list] : list -> list
:= [m:list]<list>Cases l of
nil => m
| (cons a l1) => (cons a (app l1 m))
end.
Lemma app_nil_end : (l:list)(l=(app l nil)).
Proof.
Intro l ; Elim l ; Simpl ; Auto.
Induction 1; Auto.
Qed.
Hints Resolve app_nil_end : list v62.
Lemma app_ass : (l,m,n : list)(app (app l m) n)=(app l (app m n)).
Proof.
Intros l m n ; Elim l ; Simpl ; Auto with list.
Induction 1; Auto with list.
Qed.
Hints Resolve app_ass : list v62.
Lemma ass_app : (l,m,n : list)(app l (app m n))=(app (app l m) n).
Proof.
Auto with list.
Qed.
Hints Resolve ass_app : list v62.
Definition tail :=
[l:list] <list>Cases l of (cons _ m) => m | _ => nil end : list->list.
Lemma nil_cons : (a:A)(m:list)~nil=(cons a m).
Intros; Discriminate.
Qed.
Fixpoint length [l:list] : nat
:= <nat>Cases l of (cons _ m) => (S (length m)) | _ => O end.
Section length_order.
Definition lel := [l,m:list](le (length l) (length m)).
Hints Unfold lel : list.
Variables a,b:A.
Variables l,m,n:list.
Lemma lel_refl : (lel l l).
Proof.
Unfold lel ; Auto with list.
Qed.
Lemma lel_trans : (lel l m)->(lel m n)->(lel l n).
Proof.
Unfold lel ; Intros.
Apply le_trans with (length m) ; Auto with list.
Qed.
Lemma lel_cons_cons : (lel l m)->(lel (cons a l) (cons b m)).
Proof.
Unfold lel ; Simpl ; Auto with list arith.
Qed.
Lemma lel_cons : (lel l m)->(lel l (cons b m)).
Proof.
Unfold lel ; Simpl ; Auto with list arith.
Qed.
Lemma lel_tail : (lel (cons a l) (cons b m)) -> (lel l m).
Proof.
Unfold lel ; Simpl ; Auto with list arith.
Qed.
Lemma lel_nil : (l':list)(lel l' nil)->(nil=l').
Proof.
Intro l' ; Elim l' ; Auto with list arith.
Intros a' y H H0.
Absurd (le (S (length y)) O); Auto with list arith.
Qed.
End length_order.
Hints Resolve lel_refl lel_cons_cons lel_cons lel_nil lel_nil nil_cons : list v62.
Fixpoint In [a:A;l:list] : Prop :=
Cases l of
nil => False
| (cons b m) => (b=a)\/(In a m)
end.
Lemma in_eq : (a:A)(l:list)(In a (cons a l)).
Proof.
Simpl ; Auto with list.
Qed.
Hints Resolve in_eq : list v62.
Lemma in_cons : (a,b:A)(l:list)(In b l)->(In b (cons a l)).
Proof.
Simpl ; Auto with list.
Qed.
Hints Resolve in_cons : list v62.
Lemma in_app_or : (l,m:list)(a:A)(In a (app l m))->((In a l)\/(In a m)).
Proof.
Intros l m a.
Elim l ; Simpl ; Auto with list.
Intros a0 y H H0.
Elim H0 ; Auto with list.
Intro H1.
Elim (H H1) ; Auto with list.
Qed.
Hints Immediate in_app_or : list v62.
Lemma in_or_app : (l,m:list)(a:A)((In a l)\/(In a m))->(In a (app l m)).
Proof.
Intros l m a.
Elim l ; Simpl ; Intro H.
Elim H ; Auto with list ; Intro H0.
Elim H0.
Intros y H0 H1.
Elim H1 ; Auto 4 with list.
Intro H2.
Elim H2 ; Auto with list.
Qed.
Hints Resolve in_or_app : list v62.
Definition incl := [l,m:list](a:A)(In a l)->(In a m).
Hints Unfold incl : list v62.
Lemma incl_refl : (l:list)(incl l l).
Proof.
Auto with list.
Qed.
Hints Resolve incl_refl : list v62.
Lemma incl_tl : (a:A)(l,m:list)(incl l m)->(incl l (cons a m)).
Proof.
Auto with list.
Qed.
Hints Immediate incl_tl : list v62.
Lemma incl_tran : (l,m,n:list)(incl l m)->(incl m n)->(incl l n).
Proof.
Auto with list.
Qed.
Lemma incl_appl : (l,m,n:list)(incl l n)->(incl l (app n m)).
Proof.
Auto with list.
Qed.
Hints Immediate incl_appl : list v62.
Lemma incl_appr : (l,m,n:list)(incl l n)->(incl l (app m n)).
Proof.
Auto with list.
Qed.
Hints Immediate incl_appr : list v62.
Lemma incl_cons : (a:A)(l,m:list)(In a m)->(incl l m)->(incl (cons a l) m).
Proof.
Unfold incl ; Simpl ; Intros a l m H H0 a0 H1.
Elim H1.
Elim H1 ; Auto with list ; Intro H2.
Elim H2 ; Auto with list.
Auto with list.
Qed.
Hints Resolve incl_cons : list v62.
Lemma incl_app : (l,m,n:list)(incl l n)->(incl m n)->(incl (app l m) n).
Proof.
Unfold incl ; Simpl ; Intros l m n H H0 a H1.
Elim (in_app_or l m a) ; Auto with list.
Qed.
Hints Resolve incl_app : list v62.