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Diffstat (limited to 'theories/MSets/MSetToFiniteSet.v')
-rw-r--r-- | theories/MSets/MSetToFiniteSet.v | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/theories/MSets/MSetToFiniteSet.v b/theories/MSets/MSetToFiniteSet.v new file mode 100644 index 00000000..f0b964cf --- /dev/null +++ b/theories/MSets/MSetToFiniteSet.v @@ -0,0 +1,158 @@ +(***********************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * INRIA-Rocquencourt & LRI-CNRS-Orsay *) +(* \VV/ *************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(***********************************************************************) + +(* $Id$ *) + +(** * Finite sets library : conversion to old [Finite_sets] *) + +Require Import Ensembles Finite_sets. +Require Import MSetInterface MSetProperties OrdersEx. + +(** * Going from [MSets] with usual Leibniz equality + to the good old [Ensembles] and [Finite_sets] theory. *) + +Module WS_to_Finite_set (U:UsualDecidableType)(M: WSetsOn U). + Module MP:= WPropertiesOn U M. + Import M MP FM Ensembles Finite_sets. + + Definition mkEns : M.t -> Ensemble M.elt := + fun s x => M.In x s. + + Notation " !! " := mkEns. + + Lemma In_In : forall s x, M.In x s <-> In _ (!!s) x. + Proof. + unfold In; compute; auto with extcore. + Qed. + + Lemma Subset_Included : forall s s', s[<=]s' <-> Included _ (!!s) (!!s'). + Proof. + unfold Subset, Included, In, mkEns; intuition. + Qed. + + Notation " a === b " := (Same_set M.elt a b) (at level 70, no associativity). + + Lemma Equal_Same_set : forall s s', s[=]s' <-> !!s === !!s'. + Proof. + intros. + rewrite double_inclusion. + unfold Subset, Included, Same_set, In, mkEns; intuition. + Qed. + + Lemma empty_Empty_Set : !!M.empty === Empty_set _. + Proof. + unfold Same_set, Included, mkEns, In. + split; intro; set_iff; inversion 1. + Qed. + + Lemma Empty_Empty_set : forall s, Empty s -> !!s === Empty_set _. + Proof. + unfold Same_set, Included, mkEns, In. + split; intros. + destruct(H x H0). + inversion H0. + Qed. + + Lemma singleton_Singleton : forall x, !!(M.singleton x) === Singleton _ x . + Proof. + unfold Same_set, Included, mkEns, In. + split; intro; set_iff; inversion 1; try constructor; auto. + Qed. + + Lemma union_Union : forall s s', !!(union s s') === Union _ (!!s) (!!s'). + Proof. + unfold Same_set, Included, mkEns, In. + split; intro; set_iff; inversion 1; [ constructor 1 | constructor 2 | | ]; auto. + Qed. + + Lemma inter_Intersection : forall s s', !!(inter s s') === Intersection _ (!!s) (!!s'). + Proof. + unfold Same_set, Included, mkEns, In. + split; intro; set_iff; inversion 1; try constructor; auto. + Qed. + + Lemma add_Add : forall x s, !!(add x s) === Add _ (!!s) x. + Proof. + unfold Same_set, Included, mkEns, In. + split; intro; set_iff; inversion 1; auto with sets. + inversion H0. + constructor 2; constructor. + constructor 1; auto. + Qed. + + Lemma Add_Add : forall x s s', MP.Add x s s' -> !!s' === Add _ (!!s) x. + Proof. + unfold Same_set, Included, mkEns, In. + split; intros. + red in H; rewrite H in H0. + destruct H0. + inversion H0. + constructor 2; constructor. + constructor 1; auto. + red in H; rewrite H. + inversion H0; auto. + inversion H1; auto. + Qed. + + Lemma remove_Subtract : forall x s, !!(remove x s) === Subtract _ (!!s) x. + Proof. + unfold Same_set, Included, mkEns, In. + split; intro; set_iff; inversion 1; auto with sets. + split; auto. + contradict H1. + inversion H1; auto. + Qed. + + Lemma mkEns_Finite : forall s, Finite _ (!!s). + Proof. + intro s; pattern s; apply set_induction; clear s; intros. + intros; replace (!!s) with (Empty_set elt); auto with sets. + symmetry; apply Extensionality_Ensembles. + apply Empty_Empty_set; auto. + replace (!!s') with (Add _ (!!s) x). + constructor 2; auto. + symmetry; apply Extensionality_Ensembles. + apply Add_Add; auto. + Qed. + + Lemma mkEns_cardinal : forall s, cardinal _ (!!s) (M.cardinal s). + Proof. + intro s; pattern s; apply set_induction; clear s; intros. + intros; replace (!!s) with (Empty_set elt); auto with sets. + rewrite MP.cardinal_1; auto with sets. + symmetry; apply Extensionality_Ensembles. + apply Empty_Empty_set; auto. + replace (!!s') with (Add _ (!!s) x). + rewrite (cardinal_2 H0 H1); auto with sets. + symmetry; apply Extensionality_Ensembles. + apply Add_Add; auto. + Qed. + + (** we can even build a function from Finite Ensemble to MSet + ... at least in Prop. *) + + Lemma Ens_to_MSet : forall e : Ensemble M.elt, Finite _ e -> + exists s:M.t, !!s === e. + Proof. + induction 1. + exists M.empty. + apply empty_Empty_Set. + destruct IHFinite as (s,Hs). + exists (M.add x s). + apply Extensionality_Ensembles in Hs. + rewrite <- Hs. + apply add_Add. + Qed. + +End WS_to_Finite_set. + + +Module S_to_Finite_set (U:UsualOrderedType)(M: SetsOn U) := + WS_to_Finite_set U M. + + |