diff options
Diffstat (limited to 'theories7/Arith/Mult.v')
-rwxr-xr-x | theories7/Arith/Mult.v | 224 |
1 files changed, 0 insertions, 224 deletions
diff --git a/theories7/Arith/Mult.v b/theories7/Arith/Mult.v deleted file mode 100755 index 9bd4aaf9..00000000 --- a/theories7/Arith/Mult.v +++ /dev/null @@ -1,224 +0,0 @@ -(************************************************************************) -(* v * The Coq Proof Assistant / The Coq Development Team *) -(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *) -(* \VV/ **************************************************************) -(* // * This file is distributed under the terms of the *) -(* * GNU Lesser General Public License Version 2.1 *) -(************************************************************************) - -(*i $Id: Mult.v,v 1.1.2.1 2004/07/16 19:31:25 herbelin Exp $ i*) - -Require Export Plus. -Require Export Minus. -Require Export Lt. -Require Export Le. - -V7only [Import nat_scope.]. -Open Local Scope nat_scope. - -Implicit Variables Type m,n,p:nat. - -(** Zero property *) - -Lemma mult_0_r : (n:nat) (mult n O)=O. -Proof. -Intro; Symmetry; Apply mult_n_O. -Qed. - -Lemma mult_0_l : (n:nat) (mult O n)=O. -Proof. -Reflexivity. -Qed. - -(** Distributivity *) - -Lemma mult_plus_distr : - (n,m,p:nat)((mult (plus n m) p)=(plus (mult n p) (mult m p))). -Proof. -Intros; Elim n; Simpl; Intros; Auto with arith. -Elim plus_assoc_l; Elim H; Auto with arith. -Qed. -Hints Resolve mult_plus_distr : arith v62. - -Lemma mult_plus_distr_r : (n,m,p:nat) (mult n (plus m p))=(plus (mult n m) (mult n p)). -Proof. - NewInduction n. Trivial. - Intros. Simpl. Rewrite (IHn m p). Apply sym_eq. Apply plus_permute_2_in_4. -Qed. - -Lemma mult_minus_distr : (n,m,p:nat)((mult (minus n m) p)=(minus (mult n p) (mult m p))). -Proof. -Intros; Pattern n m; Apply nat_double_ind; Simpl; Intros; Auto with arith. -Elim minus_plus_simpl; Auto with arith. -Qed. -Hints Resolve mult_minus_distr : arith v62. - -(** Associativity *) - -Lemma mult_assoc_r : (n,m,p:nat)((mult (mult n m) p) = (mult n (mult m p))). -Proof. -Intros; Elim n; Intros; Simpl; Auto with arith. -Rewrite mult_plus_distr. -Elim H; Auto with arith. -Qed. -Hints Resolve mult_assoc_r : arith v62. - -Lemma mult_assoc_l : (n,m,p:nat)(mult n (mult m p)) = (mult (mult n m) p). -Proof. -Auto with arith. -Qed. -Hints Resolve mult_assoc_l : arith v62. - -(** Commutativity *) - -Lemma mult_sym : (n,m:nat)(mult n m)=(mult m n). -Proof. -Intros; Elim n; Intros; Simpl; Auto with arith. -Elim mult_n_Sm. -Elim H; Apply plus_sym. -Qed. -Hints Resolve mult_sym : arith v62. - -(** 1 is neutral *) - -Lemma mult_1_n : (n:nat)(mult (S O) n)=n. -Proof. -Simpl; Auto with arith. -Qed. -Hints Resolve mult_1_n : arith v62. - -Lemma mult_n_1 : (n:nat)(mult n (S O))=n. -Proof. -Intro; Elim mult_sym; Auto with arith. -Qed. -Hints Resolve mult_n_1 : arith v62. - -(** Compatibility with orders *) - -Lemma mult_O_le : (n,m:nat)(m=O)\/(le n (mult m n)). -Proof. -NewInduction m; Simpl; Auto with arith. -Qed. -Hints Resolve mult_O_le : arith v62. - -Lemma mult_le_compat_l : (n,m,p:nat) (le n m) -> (le (mult p n) (mult p m)). -Proof. - NewInduction p as [|p IHp]. Intros. Simpl. Apply le_n. - Intros. Simpl. Apply le_plus_plus. Assumption. - Apply IHp. Assumption. -Qed. -Hints Resolve mult_le_compat_l : arith. -V7only [ -Notation mult_le := [m,n,p:nat](mult_le_compat_l p n m). -]. - - -Lemma le_mult_right : (m,n,p:nat)(le m n)->(le (mult m p) (mult n p)). -Intros m n p H. -Rewrite mult_sym. Rewrite (mult_sym n). -Auto with arith. -Qed. - -Lemma le_mult_mult : - (m,n,p,q:nat)(le m n)->(le p q)->(le (mult m p) (mult n q)). -Proof. -Intros m n p q Hmn Hpq; NewInduction Hmn. -NewInduction Hpq. -(* m*p<=m*p *) -Apply le_n. -(* m*p<=m*m0 -> m*p<=m*(S m0) *) -Rewrite <- mult_n_Sm; Apply le_trans with (mult m m0). -Assumption. -Apply le_plus_l. -(* m*p<=m0*q -> m*p<=(S m0)*q *) -Simpl; Apply le_trans with (mult m0 q). -Assumption. -Apply le_plus_r. -Qed. - -Lemma mult_lt : (m,n,p:nat) (lt n p) -> (lt (mult (S m) n) (mult (S m) p)). -Proof. - Intro m; NewInduction m. Intros. Simpl. Rewrite <- plus_n_O. Rewrite <- plus_n_O. Assumption. - Intros. Exact (lt_plus_plus ? ? ? ? H (IHm ? ? H)). -Qed. - -Hints Resolve mult_lt : arith. -V7only [ -Notation lt_mult_left := mult_lt. -(* Theorem lt_mult_left : - (x,y,z:nat) (lt x y) -> (lt (mult (S z) x) (mult (S z) y)). -*) -]. - -Lemma lt_mult_right : - (m,n,p:nat) (lt m n) -> (lt (0) p) -> (lt (mult m p) (mult n p)). -Intros m n p H H0. -NewInduction p. -Elim (lt_n_n ? H0). -Rewrite mult_sym. -Replace (mult n (S p)) with (mult (S p) n); Auto with arith. -Qed. - -Lemma mult_le_conv_1 : (m,n,p:nat) (le (mult (S m) n) (mult (S m) p)) -> (le n p). -Proof. - Intros m n p H. Elim (le_or_lt n p). Trivial. - Intro H0. Cut (lt (mult (S m) n) (mult (S m) n)). Intro. Elim (lt_n_n ? H1). - Apply le_lt_trans with m:=(mult (S m) p). Assumption. - Apply mult_lt. Assumption. -Qed. - -(** n|->2*n and n|->2n+1 have disjoint image *) - -V7only [ (* From Zdivides *) ]. -Theorem odd_even_lem: - (p, q : ?) ~ (plus (mult (2) p) (1)) = (mult (2) q). -Intros p; Elim p; Auto. -Intros q; Case q; Simpl. -Red; Intros; Discriminate. -Intros q'; Rewrite [x, y : ?] (plus_sym x (S y)); Simpl; Red; Intros; - Discriminate. -Intros p' H q; Case q. -Simpl; Red; Intros; Discriminate. -Intros q'; Red; Intros H0; Case (H q'). -Replace (mult (S (S O)) q') with (minus (mult (S (S O)) (S q')) (2)). -Rewrite <- H0; Simpl; Auto. -Repeat Rewrite [x, y : ?] (plus_sym x (S y)); Simpl; Auto. -Simpl; Repeat Rewrite [x, y : ?] (plus_sym x (S y)); Simpl; Auto. -Case q'; Simpl; Auto. -Qed. - - -(** Tail-recursive mult *) - -(** [tail_mult] is an alternative definition for [mult] which is - tail-recursive, whereas [mult] is not. This can be useful - when extracting programs. *) - -Fixpoint mult_acc [s,m,n:nat] : nat := - Cases n of - O => s - | (S p) => (mult_acc (tail_plus m s) m p) - end. - -Lemma mult_acc_aux : (n,s,m:nat)(plus s (mult n m))= (mult_acc s m n). -Proof. -NewInduction n as [|p IHp]; Simpl;Auto. -Intros s m; Rewrite <- plus_tail_plus; Rewrite <- IHp. -Rewrite <- plus_assoc_r; Apply (f_equal2 nat nat);Auto. -Rewrite plus_sym;Auto. -Qed. - -Definition tail_mult := [n,m:nat](mult_acc O m n). - -Lemma mult_tail_mult : (n,m:nat)(mult n m)=(tail_mult n m). -Proof. -Intros; Unfold tail_mult; Rewrite <- mult_acc_aux;Auto. -Qed. - -(** [TailSimpl] transforms any [tail_plus] and [tail_mult] into [plus] - and [mult] and simplify *) - -Tactic Definition TailSimpl := - Repeat Rewrite <- plus_tail_plus; - Repeat Rewrite <- mult_tail_mult; - Simpl. |