Lvc.Constr.MapAgreement
Require Export Setoid Coq.Classes.Morphisms.
Require Import EqDec Computable Util AutoIndTac.
Require Export CSet Containers.SetDecide.
Require Export MapBasics MapLookup.
Set Implicit Arguments.
Hint Resolve Equivalence_Reflexive Equivalence_Symmetric Equivalence_Transitive.
Section MapAgreement.
Open Scope fmap_scope.
Variable X : Type.
Context `{OrderedType X}.
Variable Y : Type.
Definition agree_on (R:relation Y) (D:set X) (E E':X → Y) :=
∀ x, x ∈ D → R (E x) (E' x).
Global Instance agree_on_refl R `{Reflexive Y R} L
: Reflexive (agree_on R L).
Proof.
firstorder.
Qed.
Global Instance agree_on_sym R `{Symmetric Y R} L
: Symmetric (agree_on R L).
Proof.
intros; hnf; firstorder.
Qed.
Global Instance agree_on_trans R `{Transitive Y R} L
: Transitive (agree_on R L).
Proof.
hnf; intros; hnf; intros. transitivity (y x0); eauto.
Qed.
Global Instance agree_on_equivalence `{Equivalence Y} {s:set X}
: Equivalence (agree_on R s).
Proof.
econstructor; eauto using agree_on_refl, agree_on_sym, agree_on_trans.
Qed.
Lemma agree_on_update (R:relation Y) L (E E':X→Y) (x:X) (v v':Y)
: R v v' → agree_on R L E E' → agree_on R L (E[x<-v]) (E'[x<-v']).
Proof.
intros. hnf; intros; lud; eauto.
Qed.
Lemma agree_on_incl R (bv lv:set X) (E E': X → Y)
: agree_on R lv E E'
→ bv ⊆ lv
→ agree_on R bv E E'.
Proof.
firstorder.
Qed.
Lemma agree_on_update_same (R:relation Y) (lv:set X) (E E':X → Y) x v v'
: R v v'
→ agree_on R (lv \ singleton x) E E'
→ agree_on R lv (E [x <- v]) (E' [x <- v']).
Proof.
intros ? A. hnf; intros; lud; eauto;
eapply A. eapply in_in_minus; eauto. cset_tac.
Qed.
Lemma agree_on_update_any_same (R:relation Y) (lv:set X) (E E':X → Y) x v v'
: R v v'
→ agree_on R lv E E'
→ agree_on R (lv ∪ singleton x ) (E [x <- v]) (E' [x <- v']).
Proof.
intros inR A. hnf; intros; lud; eauto; eapply A.
eapply union_cases in H0; destruct H0; eauto. cset_tac.
Qed.
Lemma agree_on_update_dead R (lv:set X) (E E':X → Y) x v
: ¬x ∈ lv
→ agree_on R lv E E'
→ agree_on R lv (E [x <- v]) E'.
Proof.
intros A B.
hnf; intros; lud. cset_tac.
eapply B; eauto.
Qed.
Lemma agree_on_update_inv R (lv:set X) (E E':X → Y) x v
: agree_on R lv (E [x <- v]) E'
→ agree_on R (lv \ singleton x) E E'.
Proof.
intros A B.
hnf; intros. cset_tac'.
exploit A; eauto. lud; cset_tac.
Qed.
Lemma agree_on_update_dead_both R (lv:set X) (E E':X → Y) x v v'
: ¬x ∈ lv
→ agree_on R lv E E'
→ agree_on R lv (E [x <- v]) (E'[x <- v']).
Proof.
intros A B.
hnf; intros. lud; eauto.
Qed.
End MapAgreement.
Lemma lookup_set_agree X `{OrderedType X} Y `{OrderedType Y} s (m m':X → Y)
`{Proper _ (respectful _eq _eq) m} `{Proper _ (respectful _eq _eq) m'}
: @agree_on _ _ _ _eq s m m' → lookup_set m s [=] lookup_set m' s.
Proof.
intros; split; intros.
- eapply lookup_set_spec; eauto. eapply lookup_set_spec in H4; dcr; eauto.
eexists x; split; eauto. rewrite H7; eauto. eapply H3; eauto.
- eapply lookup_set_spec; eauto. eapply lookup_set_spec in H4; dcr; eauto.
eexists x; split; eauto. rewrite H7; symmetry; eapply H3; eauto.
Qed.
Definition eagree_on X `{OrderedType X} Y R `{Equivalence Y R} D E E'
:= @agree_on X _ Y R D E E'.
Arguments eagree_on {X} {H} {Y} {R} {H0} D E E'.
(*Global Instance test X `{OrderedType X} Y `{Equivalence Y}
: Proper ((@feq X _ _ Y _ _) ==> (@feq X _ _ Y _ _) ==> iff) R.
*)
Global Instance eq_cset_agree_on_morphism X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Equal ==> (@feq X Y R) ==> (@feq X Y R) ==> iff) (agree_on R).
Proof.
unfold Proper, respectful, agree_on; split; intros.
+ rewrite <- H2 in H6. eauto.
+ rewrite H2 in H6. eauto.
Qed.
Global Instance incl_agree_on_morphism X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Equal ==> (@feq X Y R) ==> (@feq X Y R) ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, agree_on, flip, impl; intros.
rewrite H2 in H6; eauto.
Qed.
Global Instance incl_agree_on_morphism_eq X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Equal ==> eq ==> eq ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, agree_on, flip, impl; intros; subst.
rewrite H2 in H6; eauto.
Qed.
Instance agree_on_iff_morph X `{OrderedType X} Y `{OrderedType Y} s
: Proper (@agree_on X _ Y _eq s ==> @agree_on X _ Y _eq s ==> iff) (@agree_on X _ Y _eq s) | 1.
Proof.
eapply (PER_morphism (Equivalence_PER (agree_on_equivalence (Y:=Y)))).
Qed.
Instance agree_on_1_iff_morph X `{OrderedType X} Y `{OrderedType Y} s
: Proper (@agree_on X _ Y _eq s ==> eq ==> iff) (@agree_on X _ Y _eq s) | 1.
Proof.
unfold Proper, respectful; intros; subst.
split; intros.
- etransitivity; [ symmetry; eassumption | eassumption].
- etransitivity; [ eassumption | eassumption].
Qed.
Instance agree_on_1_iff_morph_eq X `{OrderedType X} Y s
: Proper (@agree_on X _ Y eq s ==> eq ==> iff) (@agree_on X _ Y eq s) | 1.
Proof.
unfold Proper, respectful; intros; subst.
split; intros.
- etransitivity; [ symmetry; eassumption | eassumption].
- etransitivity; [ eassumption | eassumption].
Qed.
Instance agree_on_1_impl_morph X `{OrderedType X} Y s
: Proper (@agree_on X _ Y eq s ==> eq ==> impl) (@agree_on X _ Y eq s) | 1.
Proof.
unfold Proper, respectful; intros; subst.
hnf; intros.
- etransitivity; [ symmetry; eassumption | eassumption].
Qed.
Lemma eagree_on_union {X} `{OrderedType X} {Y} (f:X→Y) g D D'
: eagree_on D f g
→ eagree_on D' f g
→ eagree_on (D ∪ D') f g.
Proof.
intros. hnf; intros. cset_tac.
Qed.
Lemma agree_on_union {X} `{OrderedType X} {Y} (f:X→Y) R g D D'
: agree_on R D f g
→ agree_on R D' f g
→ agree_on R (D ∪ D') f g.
Proof.
intros. hnf; intros. cset_tac.
Qed.
Global Instance agree_on_computable {X} `{OrderedType X} {Y} `{OrderedType Y}
(f g:X→Y) D `{Proper _ (_eq ==> _eq) f} `{Proper _ (_eq ==> _eq) g}
: Computable (eagree_on D f g).
Proof.
case_eq (for_all (fun x ⇒ @decision_procedure (f x === g x) _) D); intros.
eapply for_all_iff in H3. left. hnf; intros.
specialize (H3 _ H4). simpl in H3.
unfold decision_procedure in H3; simpl in H3.
destruct (equiv_computable Y (f x) (g x)); isabsurd; eauto.
hnf; intros. simpl.
destruct (decision_procedure (f x === g x));
destruct (decision_procedure (f y === g y)); try reflexivity.
exfalso. eapply n. rewrite <- H5; eauto.
exfalso. eapply n. rewrite H5; eauto.
right. intro.
change False with (Is_true false). rewrite <- H3.
eapply Is_true_eq_left. rewrite <- for_all_iff.
hnf; intros. simpl. specialize (H4 _ H5).
destruct (equiv_computable Y (f x) (g x)); isabsurd; eauto.
hnf; intros. simpl.
destruct (decision_procedure (f x === g x));
destruct (decision_procedure (f y === g y)); try reflexivity.
exfalso. eapply n. rewrite <- H5; eauto.
exfalso. eapply n. rewrite H5; eauto.
Defined.
Lemma map_agree X `{OrderedType X} Y `{OrderedType Y}
lv (f:X→Y) `{Proper _ (_eq ==> _eq) f} (g:X→Y) `{Proper _ (_eq ==> _eq) g}
: agree_on _eq lv f g
→ map f lv [=] map g lv.
Proof.
intros. intro.
repeat rewrite map_iff; eauto.
split; intros []; intros; dcr; eexists x; split; eauto.
+ specialize (H3 x H5). rewrite <- H3; eauto.
+ specialize (H3 x H5). rewrite H3; eauto.
Qed.
Hint Extern 10 (agree_on _ _?a ?a) ⇒ reflexivity.
Extraction Inline agree_on_computable.
Global Instance incl_agree_on_morphism_flip_impl X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Subset ==> eq ==> eq ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, agree_on, flip, impl; intros; subst.
rewrite H2 in H6; eauto.
Qed.
Hint Resolve agree_on_incl : cset.
Lemma agree_on_comp X `{OrderedType X} Y
(V V' V'':X→Y) (f:X→X) D `{Proper _ (_eq ==> _eq) f}
: agree_on eq (map f D) V' V''
→ agree_on eq D V (fun x ⇒ V'' (f x))
→ agree_on eq D V (fun x ⇒ V' (f x)).
Proof.
intros.
hnf; intros. rewrite H1; eauto with cset.
Qed.
Lemma agree_on_comp_both X `{OrderedType X} Y
(V V':X→Y) (f:X→X) D `{Proper _ (_eq ==> _eq) f}
`{Proper _ (_eq ==> eq) V}
`{Proper _ (_eq ==> eq) V'}
: agree_on eq (map f D) V V'
↔ agree_on eq D (fun x ⇒ V (f x)) (fun x ⇒ V' (f x)).
Proof.
split; intros Agr; hnf; intros.
+ rewrite Agr; eauto with cset.
+ eapply map_iff in H3; eauto; dcr.
exploit (Agr x0); eauto.
rewrite <- H6 in H3. eauto.
Qed.
Lemma agree_on_empty X `{OrderedType X} Y D (f g:X→Y) R
: D ⊆ ∅
→ agree_on R D f g.
Proof.
unfold agree_on; intros; exfalso; cset_tac.
Qed.
Lemma agree_on_R_impl (X : Type) `{OrderedType X} (Y : Type)
(R R':Y → Y → Prop) (D:set X) (f g:X → Y)
: agree_on R D f g
→ (∀ x, x ∈ D → R (f x) (g x) → R' (f x) (g x))
→ agree_on R' D f g.
Proof.
intros; hnf; intros; eauto.
Qed.
Instance agree_inst (X : Type) `{H : OrderedType X} (Y : Type) (R : relation Y)
: Proper (SetInterface.Equal ==> eq ==> eq ==> iff) (agree_on R).
Proof.
unfold Proper, respectful; intros; subst.
split; intros; hnf; intros; eauto; cset_tac.
Qed.
Instance agree_inst_impl (X : Type) `{H : OrderedType X} (Y : Type) (R : relation Y)
: Proper (SetInterface.Subset ==> eq ==> eq ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, flip, impl; intros; subst.
intros; hnf; intros; eauto.
Qed.
Require Import EqDec Computable Util AutoIndTac.
Require Export CSet Containers.SetDecide.
Require Export MapBasics MapLookup.
Set Implicit Arguments.
Hint Resolve Equivalence_Reflexive Equivalence_Symmetric Equivalence_Transitive.
Section MapAgreement.
Open Scope fmap_scope.
Variable X : Type.
Context `{OrderedType X}.
Variable Y : Type.
Definition agree_on (R:relation Y) (D:set X) (E E':X → Y) :=
∀ x, x ∈ D → R (E x) (E' x).
Global Instance agree_on_refl R `{Reflexive Y R} L
: Reflexive (agree_on R L).
Proof.
firstorder.
Qed.
Global Instance agree_on_sym R `{Symmetric Y R} L
: Symmetric (agree_on R L).
Proof.
intros; hnf; firstorder.
Qed.
Global Instance agree_on_trans R `{Transitive Y R} L
: Transitive (agree_on R L).
Proof.
hnf; intros; hnf; intros. transitivity (y x0); eauto.
Qed.
Global Instance agree_on_equivalence `{Equivalence Y} {s:set X}
: Equivalence (agree_on R s).
Proof.
econstructor; eauto using agree_on_refl, agree_on_sym, agree_on_trans.
Qed.
Lemma agree_on_update (R:relation Y) L (E E':X→Y) (x:X) (v v':Y)
: R v v' → agree_on R L E E' → agree_on R L (E[x<-v]) (E'[x<-v']).
Proof.
intros. hnf; intros; lud; eauto.
Qed.
Lemma agree_on_incl R (bv lv:set X) (E E': X → Y)
: agree_on R lv E E'
→ bv ⊆ lv
→ agree_on R bv E E'.
Proof.
firstorder.
Qed.
Lemma agree_on_update_same (R:relation Y) (lv:set X) (E E':X → Y) x v v'
: R v v'
→ agree_on R (lv \ singleton x) E E'
→ agree_on R lv (E [x <- v]) (E' [x <- v']).
Proof.
intros ? A. hnf; intros; lud; eauto;
eapply A. eapply in_in_minus; eauto. cset_tac.
Qed.
Lemma agree_on_update_any_same (R:relation Y) (lv:set X) (E E':X → Y) x v v'
: R v v'
→ agree_on R lv E E'
→ agree_on R (lv ∪ singleton x ) (E [x <- v]) (E' [x <- v']).
Proof.
intros inR A. hnf; intros; lud; eauto; eapply A.
eapply union_cases in H0; destruct H0; eauto. cset_tac.
Qed.
Lemma agree_on_update_dead R (lv:set X) (E E':X → Y) x v
: ¬x ∈ lv
→ agree_on R lv E E'
→ agree_on R lv (E [x <- v]) E'.
Proof.
intros A B.
hnf; intros; lud. cset_tac.
eapply B; eauto.
Qed.
Lemma agree_on_update_inv R (lv:set X) (E E':X → Y) x v
: agree_on R lv (E [x <- v]) E'
→ agree_on R (lv \ singleton x) E E'.
Proof.
intros A B.
hnf; intros. cset_tac'.
exploit A; eauto. lud; cset_tac.
Qed.
Lemma agree_on_update_dead_both R (lv:set X) (E E':X → Y) x v v'
: ¬x ∈ lv
→ agree_on R lv E E'
→ agree_on R lv (E [x <- v]) (E'[x <- v']).
Proof.
intros A B.
hnf; intros. lud; eauto.
Qed.
End MapAgreement.
Lemma lookup_set_agree X `{OrderedType X} Y `{OrderedType Y} s (m m':X → Y)
`{Proper _ (respectful _eq _eq) m} `{Proper _ (respectful _eq _eq) m'}
: @agree_on _ _ _ _eq s m m' → lookup_set m s [=] lookup_set m' s.
Proof.
intros; split; intros.
- eapply lookup_set_spec; eauto. eapply lookup_set_spec in H4; dcr; eauto.
eexists x; split; eauto. rewrite H7; eauto. eapply H3; eauto.
- eapply lookup_set_spec; eauto. eapply lookup_set_spec in H4; dcr; eauto.
eexists x; split; eauto. rewrite H7; symmetry; eapply H3; eauto.
Qed.
Definition eagree_on X `{OrderedType X} Y R `{Equivalence Y R} D E E'
:= @agree_on X _ Y R D E E'.
Arguments eagree_on {X} {H} {Y} {R} {H0} D E E'.
(*Global Instance test X `{OrderedType X} Y `{Equivalence Y}
: Proper ((@feq X _ _ Y _ _) ==> (@feq X _ _ Y _ _) ==> iff) R.
*)
Global Instance eq_cset_agree_on_morphism X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Equal ==> (@feq X Y R) ==> (@feq X Y R) ==> iff) (agree_on R).
Proof.
unfold Proper, respectful, agree_on; split; intros.
+ rewrite <- H2 in H6. eauto.
+ rewrite H2 in H6. eauto.
Qed.
Global Instance incl_agree_on_morphism X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Equal ==> (@feq X Y R) ==> (@feq X Y R) ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, agree_on, flip, impl; intros.
rewrite H2 in H6; eauto.
Qed.
Global Instance incl_agree_on_morphism_eq X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Equal ==> eq ==> eq ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, agree_on, flip, impl; intros; subst.
rewrite H2 in H6; eauto.
Qed.
Instance agree_on_iff_morph X `{OrderedType X} Y `{OrderedType Y} s
: Proper (@agree_on X _ Y _eq s ==> @agree_on X _ Y _eq s ==> iff) (@agree_on X _ Y _eq s) | 1.
Proof.
eapply (PER_morphism (Equivalence_PER (agree_on_equivalence (Y:=Y)))).
Qed.
Instance agree_on_1_iff_morph X `{OrderedType X} Y `{OrderedType Y} s
: Proper (@agree_on X _ Y _eq s ==> eq ==> iff) (@agree_on X _ Y _eq s) | 1.
Proof.
unfold Proper, respectful; intros; subst.
split; intros.
- etransitivity; [ symmetry; eassumption | eassumption].
- etransitivity; [ eassumption | eassumption].
Qed.
Instance agree_on_1_iff_morph_eq X `{OrderedType X} Y s
: Proper (@agree_on X _ Y eq s ==> eq ==> iff) (@agree_on X _ Y eq s) | 1.
Proof.
unfold Proper, respectful; intros; subst.
split; intros.
- etransitivity; [ symmetry; eassumption | eassumption].
- etransitivity; [ eassumption | eassumption].
Qed.
Instance agree_on_1_impl_morph X `{OrderedType X} Y s
: Proper (@agree_on X _ Y eq s ==> eq ==> impl) (@agree_on X _ Y eq s) | 1.
Proof.
unfold Proper, respectful; intros; subst.
hnf; intros.
- etransitivity; [ symmetry; eassumption | eassumption].
Qed.
Lemma eagree_on_union {X} `{OrderedType X} {Y} (f:X→Y) g D D'
: eagree_on D f g
→ eagree_on D' f g
→ eagree_on (D ∪ D') f g.
Proof.
intros. hnf; intros. cset_tac.
Qed.
Lemma agree_on_union {X} `{OrderedType X} {Y} (f:X→Y) R g D D'
: agree_on R D f g
→ agree_on R D' f g
→ agree_on R (D ∪ D') f g.
Proof.
intros. hnf; intros. cset_tac.
Qed.
Global Instance agree_on_computable {X} `{OrderedType X} {Y} `{OrderedType Y}
(f g:X→Y) D `{Proper _ (_eq ==> _eq) f} `{Proper _ (_eq ==> _eq) g}
: Computable (eagree_on D f g).
Proof.
case_eq (for_all (fun x ⇒ @decision_procedure (f x === g x) _) D); intros.
eapply for_all_iff in H3. left. hnf; intros.
specialize (H3 _ H4). simpl in H3.
unfold decision_procedure in H3; simpl in H3.
destruct (equiv_computable Y (f x) (g x)); isabsurd; eauto.
hnf; intros. simpl.
destruct (decision_procedure (f x === g x));
destruct (decision_procedure (f y === g y)); try reflexivity.
exfalso. eapply n. rewrite <- H5; eauto.
exfalso. eapply n. rewrite H5; eauto.
right. intro.
change False with (Is_true false). rewrite <- H3.
eapply Is_true_eq_left. rewrite <- for_all_iff.
hnf; intros. simpl. specialize (H4 _ H5).
destruct (equiv_computable Y (f x) (g x)); isabsurd; eauto.
hnf; intros. simpl.
destruct (decision_procedure (f x === g x));
destruct (decision_procedure (f y === g y)); try reflexivity.
exfalso. eapply n. rewrite <- H5; eauto.
exfalso. eapply n. rewrite H5; eauto.
Defined.
Lemma map_agree X `{OrderedType X} Y `{OrderedType Y}
lv (f:X→Y) `{Proper _ (_eq ==> _eq) f} (g:X→Y) `{Proper _ (_eq ==> _eq) g}
: agree_on _eq lv f g
→ map f lv [=] map g lv.
Proof.
intros. intro.
repeat rewrite map_iff; eauto.
split; intros []; intros; dcr; eexists x; split; eauto.
+ specialize (H3 x H5). rewrite <- H3; eauto.
+ specialize (H3 x H5). rewrite H3; eauto.
Qed.
Hint Extern 10 (agree_on _ _?a ?a) ⇒ reflexivity.
Extraction Inline agree_on_computable.
Global Instance incl_agree_on_morphism_flip_impl X `{OrderedType X} Y R `{Transitive Y R} `{Symmetric Y R}
: Proper (SetInterface.Subset ==> eq ==> eq ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, agree_on, flip, impl; intros; subst.
rewrite H2 in H6; eauto.
Qed.
Hint Resolve agree_on_incl : cset.
Lemma agree_on_comp X `{OrderedType X} Y
(V V' V'':X→Y) (f:X→X) D `{Proper _ (_eq ==> _eq) f}
: agree_on eq (map f D) V' V''
→ agree_on eq D V (fun x ⇒ V'' (f x))
→ agree_on eq D V (fun x ⇒ V' (f x)).
Proof.
intros.
hnf; intros. rewrite H1; eauto with cset.
Qed.
Lemma agree_on_comp_both X `{OrderedType X} Y
(V V':X→Y) (f:X→X) D `{Proper _ (_eq ==> _eq) f}
`{Proper _ (_eq ==> eq) V}
`{Proper _ (_eq ==> eq) V'}
: agree_on eq (map f D) V V'
↔ agree_on eq D (fun x ⇒ V (f x)) (fun x ⇒ V' (f x)).
Proof.
split; intros Agr; hnf; intros.
+ rewrite Agr; eauto with cset.
+ eapply map_iff in H3; eauto; dcr.
exploit (Agr x0); eauto.
rewrite <- H6 in H3. eauto.
Qed.
Lemma agree_on_empty X `{OrderedType X} Y D (f g:X→Y) R
: D ⊆ ∅
→ agree_on R D f g.
Proof.
unfold agree_on; intros; exfalso; cset_tac.
Qed.
Lemma agree_on_R_impl (X : Type) `{OrderedType X} (Y : Type)
(R R':Y → Y → Prop) (D:set X) (f g:X → Y)
: agree_on R D f g
→ (∀ x, x ∈ D → R (f x) (g x) → R' (f x) (g x))
→ agree_on R' D f g.
Proof.
intros; hnf; intros; eauto.
Qed.
Instance agree_inst (X : Type) `{H : OrderedType X} (Y : Type) (R : relation Y)
: Proper (SetInterface.Equal ==> eq ==> eq ==> iff) (agree_on R).
Proof.
unfold Proper, respectful; intros; subst.
split; intros; hnf; intros; eauto; cset_tac.
Qed.
Instance agree_inst_impl (X : Type) `{H : OrderedType X} (Y : Type) (R : relation Y)
: Proper (SetInterface.Subset ==> eq ==> eq ==> flip impl) (agree_on R).
Proof.
unfold Proper, respectful, flip, impl; intros; subst.
intros; hnf; intros; eauto.
Qed.