class_instances.v

From stdpp Require Import nat_cancel.
From iris.bi Require Import bi tactics.
From iris.proofmode Require Export modality_instances classes.
Set Default Proof Using "Type".
Import bi.

Section bi_instances.
Context {PROP : bi}.
Implicit Types P Q R : PROP.

(* FromAffinely *)
Global Instance from_affinely_affine P : Affine P → FromAffinely P P.
Proof. intros. by rewrite /FromAffinely affinely_elim. Qed.
Global Instance from_affinely_default P : FromAffinely (bi_affinely P) P | 100.
Proof. by rewrite /FromAffinely. Qed.

(* IntoAbsorbingly *)
Global Instance into_absorbingly_True : @IntoAbsorbingly PROP True emp | 0.
Proof. by rewrite /IntoAbsorbingly -absorbingly_True_emp absorbingly_pure. Qed.
Global Instance into_absorbingly_absorbing P : Absorbing P → IntoAbsorbingly P P | 1.
Proof. intros. by rewrite /IntoAbsorbingly absorbing_absorbingly. Qed.
Global Instance into_absorbingly_default P : IntoAbsorbingly (bi_absorbingly P) P | 100.
Proof. by rewrite /IntoAbsorbingly. Qed.

(* FromAssumption *)
Global Instance from_assumption_exact p P : FromAssumption p P P | 0.
Proof. by rewrite /FromAssumption /= affinely_persistently_if_elim. Qed.

Global Instance from_assumption_persistently_r P Q :
  FromAssumption true P Q → FromAssumption true P (bi_persistently Q).
Proof.
  rewrite /FromAssumption /= =><-.
  by rewrite -{1}affinely_persistently_idemp affinely_elim.
Qed.
Global Instance from_assumption_affinely_r P Q :
  FromAssumption true P Q → FromAssumption true P (bi_affinely Q).
Proof. rewrite /FromAssumption /= =><-. by rewrite affinely_idemp. Qed.
Global Instance from_assumption_absorbingly_r p P Q :
  FromAssumption p P Q → FromAssumption p P (bi_absorbingly Q).
Proof. rewrite /FromAssumption /= =><-. apply absorbingly_intro. Qed.

Global Instance from_assumption_affinely_persistently_l p P Q :
  FromAssumption true P Q → FromAssumption p (□ P) Q.
Proof. rewrite /FromAssumption /= =><-. by rewrite affinely_persistently_if_elim. Qed.
Global Instance from_assumption_persistently_l_true P Q :
  FromAssumption true P Q → FromAssumption true (bi_persistently P) Q.
Proof. rewrite /FromAssumption /= =><-. by rewrite persistently_idemp. Qed.
Global Instance from_assumption_persistently_l_false `{BiAffine PROP} P Q :
  FromAssumption true P Q → FromAssumption false (bi_persistently P) Q.
Proof. rewrite /FromAssumption /= =><-. by rewrite affine_affinely. Qed.
Global Instance from_assumption_affinely_l_true p P Q :
  FromAssumption p P Q → FromAssumption p (bi_affinely P) Q.
Proof. rewrite /FromAssumption /= =><-. by rewrite affinely_elim. Qed.

Global Instance from_assumption_forall {A} p (Φ : A → PROP) Q x :
  FromAssumption p (Φ x) Q → FromAssumption p (∀ x, Φ x) Q.
Proof. rewrite /FromAssumption=> <-. by rewrite forall_elim. Qed.

(* IntoPure *)
Global Instance into_pure_pure φ : @IntoPure PROP ⌜φ⌝ φ.
Proof. by rewrite /IntoPure. Qed.

Global Instance into_pure_pure_and (φ1 φ2 : Prop) P1 P2 :
  IntoPure P1 φ1 → IntoPure P2 φ2 → IntoPure (P1 ∧ P2) (φ1 ∧ φ2).
Proof. rewrite /IntoPure pure_and. by intros -> ->. Qed.
Global Instance into_pure_pure_or (φ1 φ2 : Prop) P1 P2 :
  IntoPure P1 φ1 → IntoPure P2 φ2 → IntoPure (P1 ∨ P2) (φ1 ∨ φ2).
Proof. rewrite /IntoPure pure_or. by intros -> ->. Qed.
Global Instance into_pure_pure_impl (φ1 φ2 : Prop) P1 P2 :
  FromPure false P1 φ1 → IntoPure P2 φ2 → IntoPure (P1 → P2) (φ1 → φ2).
Proof. rewrite /FromPure /IntoPure pure_impl=> <- -> //. Qed.

Global Instance into_pure_exist {A} (Φ : A → PROP) (φ : A → Prop) :
  (∀ x, IntoPure (Φ x) (φ x)) → IntoPure (∃ x, Φ x) (∃ x, φ x).
Proof. rewrite /IntoPure=>Hx. rewrite pure_exist. by setoid_rewrite Hx. Qed.
Global Instance into_pure_forall {A} (Φ : A → PROP) (φ : A → Prop) :
  (∀ x, IntoPure (Φ x) (φ x)) → IntoPure (∀ x, Φ x) (∀ x, φ x).
Proof. rewrite /IntoPure=>Hx. rewrite -pure_forall_2. by setoid_rewrite Hx. Qed.

Global Instance into_pure_pure_sep (φ1 φ2 : Prop) P1 P2 :
  IntoPure P1 φ1 → IntoPure P2 φ2 → IntoPure (P1 ∗ P2) (φ1 ∧ φ2).
Proof. rewrite /IntoPure=> -> ->. by rewrite sep_and pure_and. Qed.
Global Instance into_pure_pure_wand (φ1 φ2 : Prop) P1 P2 :
  FromPure true P1 φ1 → IntoPure P2 φ2 → IntoPure (P1 -∗ P2) (φ1 → φ2).
Proof.
  rewrite /FromPure /IntoPure=> <- -> /=.
  rewrite pure_impl -impl_wand_2. apply bi.wand_intro_l.
  rewrite {1}(persistent_absorbingly_affinely ⌜φ1⌝%I) absorbingly_sep_l
          bi.wand_elim_r absorbing //.
Qed.

Global Instance into_pure_affinely P φ :
  IntoPure P φ → IntoPure (bi_affinely P) φ.
Proof. rewrite /IntoPure=> ->. apply affinely_elim. Qed.
Global Instance into_pure_absorbingly P φ : IntoPure P φ → IntoPure (bi_absorbingly P) φ.
Proof. rewrite /IntoPure=> ->. by rewrite absorbingly_pure. Qed.
Global Instance into_pure_persistently P φ :
  IntoPure P φ → IntoPure (bi_persistently P) φ.
Proof. rewrite /IntoPure=> ->. apply: persistently_elim. Qed.
Global Instance into_pure_embed `{BiEmbed PROP PROP'} P φ :
  IntoPure P φ → IntoPure ⎡P⎤ φ.
Proof. rewrite /IntoPure=> ->. by rewrite embed_pure. Qed.

(* FromPure *)
Global Instance from_pure_pure a φ : @FromPure PROP a ⌜φ⌝ φ.
Proof. rewrite /FromPure. apply affinely_if_elim. Qed.
Global Instance from_pure_pure_and a (φ1 φ2 : Prop) P1 P2 :
  FromPure a P1 φ1 → FromPure a P2 φ2 → FromPure a (P1 ∧ P2) (φ1 ∧ φ2).
Proof. rewrite /FromPure pure_and=> <- <- /=. by rewrite affinely_if_and. Qed.
Global Instance from_pure_pure_or a (φ1 φ2 : Prop) P1 P2 :
  FromPure a P1 φ1 → FromPure a P2 φ2 → FromPure a (P1 ∨ P2) (φ1 ∨ φ2).
Proof. by rewrite /FromPure pure_or affinely_if_or=><- <-. Qed.
Global Instance from_pure_pure_impl a (φ1 φ2 : Prop) P1 P2 :
  IntoPure P1 φ1 → FromPure a P2 φ2 → FromPure a (P1 → P2) (φ1 → φ2).
Proof.
  rewrite /FromPure /IntoPure pure_impl=> -> <-. destruct a=>//=.
  apply bi.impl_intro_l. by rewrite affinely_and_r bi.impl_elim_r.
Qed.

Global Instance from_pure_exist {A} a (Φ : A → PROP) (φ : A → Prop) :
  (∀ x, FromPure a (Φ x) (φ x)) → FromPure a (∃ x, Φ x) (∃ x, φ x).
Proof.
  rewrite /FromPure=>Hx. rewrite pure_exist affinely_if_exist.
  by setoid_rewrite Hx.
Qed.
Global Instance from_pure_forall {A} a (Φ : A → PROP) (φ : A → Prop) :
  (∀ x, FromPure a (Φ x) (φ x)) → FromPure a (∀ x, Φ x) (∀ x, φ x).
Proof.
  rewrite /FromPure=>Hx. rewrite pure_forall. setoid_rewrite <-Hx.
  destruct a=>//=. apply affinely_forall.
Qed.

Global Instance from_pure_pure_sep_true (φ1 φ2 : Prop) P1 P2 :
  FromPure true P1 φ1 → FromPure true P2 φ2 → FromPure true (P1 ∗ P2) (φ1 ∧ φ2).
Proof.
  rewrite /FromPure=> <- <- /=.
  by rewrite -persistent_and_affinely_sep_l affinely_and_r pure_and.
Qed.
Global Instance from_pure_pure_sep_false_l (φ1 φ2 : Prop) P1 P2 :
  FromPure false P1 φ1 → FromPure true P2 φ2 → FromPure false (P1 ∗ P2) (φ1 ∧ φ2).
Proof.
  rewrite /FromPure=> <- <- /=. by rewrite -persistent_and_affinely_sep_r pure_and.
Qed.
Global Instance from_pure_pure_sep_false_r (φ1 φ2 : Prop) P1 P2 :
  FromPure true P1 φ1 → FromPure false P2 φ2 → FromPure false (P1 ∗ P2) (φ1 ∧ φ2).
Proof.
  rewrite /FromPure=> <- <- /=. by rewrite -persistent_and_affinely_sep_l pure_and.
Qed.
Global Instance from_pure_pure_wand (φ1 φ2 : Prop) a P1 P2 :
  IntoPure P1 φ1 → FromPure false P2 φ2 → FromPure a (P1 -∗ P2) (φ1 → φ2).
Proof.
  rewrite /FromPure /IntoPure=> -> <- /=.
  by rewrite bi.affinely_if_elim pure_wand_forall pure_impl pure_impl_forall.
Qed.

Global Instance from_pure_persistently P a φ :
  FromPure true P φ → FromPure a (bi_persistently P) φ.
Proof.
  rewrite /FromPure=> <- /=.
  by rewrite persistently_affinely affinely_if_elim persistently_pure.
Qed.
Global Instance from_pure_affinely_true P φ :
  FromPure true P φ → FromPure true (bi_affinely P) φ.
Proof. rewrite /FromPure=><- /=. by rewrite affinely_idemp. Qed.
Global Instance from_pure_affinely_false P φ `{!Affine P} :
  FromPure false P φ → FromPure false (bi_affinely P) φ.
Proof. rewrite /FromPure /= affine_affinely //. Qed.

Global Instance from_pure_absorbingly P φ :
  FromPure true P φ → FromPure false (bi_absorbingly P) φ.
Proof. rewrite /FromPure=> <- /=. apply persistent_absorbingly_affinely, _. Qed.
Global Instance from_pure_embed `{BiEmbed PROP PROP'} a P φ :
  FromPure a P φ → FromPure a ⎡P⎤ φ.
Proof. rewrite /FromPure=> <-. by rewrite embed_affinely_if embed_pure. Qed.

(* IntoPersistent *)
Global Instance into_persistent_persistently p P Q :
  IntoPersistent true P Q → IntoPersistent p (bi_persistently P) Q | 0.
Proof.
  rewrite /IntoPersistent /= => ->.
  destruct p; simpl; auto using persistently_idemp_1.
Qed.
Global Instance into_persistent_affinely p P Q :
  IntoPersistent p P Q → IntoPersistent p (bi_affinely P) Q | 0.
Proof. rewrite /IntoPersistent /= => <-. by rewrite affinely_elim. Qed.
Global Instance into_persistent_embed `{BiEmbed PROP PROP'} p P Q :
  IntoPersistent p P Q → IntoPersistent p ⎡P⎤ ⎡Q⎤ | 0.
Proof.
  rewrite /IntoPersistent -embed_persistently -embed_persistently_if=> -> //.
Qed.
Global Instance into_persistent_here P : IntoPersistent true P P | 1.
Proof. by rewrite /IntoPersistent. Qed.
Global Instance into_persistent_persistent P :
  Persistent P → IntoPersistent false P P | 100.
Proof. intros. by rewrite /IntoPersistent. Qed.

(* FromModal *)
Global Instance from_modal_affinely P :
  FromModal modality_affinely (bi_affinely P) (bi_affinely P) P | 2.
Proof. by rewrite /FromModal. Qed.

Global Instance from_modal_persistently P :
  FromModal modality_persistently (bi_persistently P) (bi_persistently P) P | 2.
Proof. by rewrite /FromModal. Qed.
Global Instance from_modal_affinely_persistently P :
  FromModal modality_affinely_persistently (□ P) (□ P) P | 1.
Proof. by rewrite /FromModal. Qed.
Global Instance from_modal_affinely_persistently_affine_bi P :
  BiAffine PROP → FromModal modality_persistently (□ P) (□ P) P | 0.
Proof. intros. by rewrite /FromModal /= affine_affinely. Qed.

Global Instance from_modal_absorbingly P :
  FromModal modality_id (bi_absorbingly P) (bi_absorbingly P) P.
Proof. by rewrite /FromModal /= -absorbingly_intro. Qed.

(* When having a modality nested in an embedding, e.g. [ ⎡|==> P⎤ ], we prefer
the embedding over the modality. *)
Global Instance from_modal_embed `{BiEmbed PROP PROP'} (P : PROP) :
  FromModal (@modality_embed PROP PROP' _) ⎡P⎤ ⎡P⎤ P.
Proof. by rewrite /FromModal. Qed.

Global Instance from_modal_id_embed `{BiEmbed PROP PROP'} `(sel : A) P Q :
  FromModal modality_id sel P Q →
  FromModal modality_id sel ⎡P⎤ ⎡Q⎤ | 100.
Proof. by rewrite /FromModal /= =><-. Qed.

Global Instance from_modal_affinely_embed `{BiEmbed PROP PROP'} `(sel : A) P Q :
  FromModal modality_affinely sel P Q →
  FromModal modality_affinely sel ⎡P⎤ ⎡Q⎤ | 100.
Proof. rewrite /FromModal /= =><-. by rewrite embed_affinely. Qed.
Global Instance from_modal_persistently_embed `{BiEmbed PROP PROP'} `(sel : A) P Q :
  FromModal modality_persistently sel P Q →
  FromModal modality_persistently sel ⎡P⎤ ⎡Q⎤ | 100.
Proof. rewrite /FromModal /= =><-. by rewrite embed_persistently. Qed.
Global Instance from_modal_affinely_persistently_embed `{BiEmbed PROP PROP'} `(sel : A) P Q :
  FromModal modality_affinely_persistently sel P Q →
  FromModal modality_affinely_persistently sel ⎡P⎤ ⎡Q⎤ | 100.
Proof.
  rewrite /FromModal /= =><-. by rewrite embed_affinely embed_persistently.
Qed.

(* IntoWand *)
Global Instance into_wand_wand p q P Q P' :
  FromAssumption q P P' → IntoWand p q (P' -∗ Q) P Q.
Proof.
  rewrite /FromAssumption /IntoWand=> HP. by rewrite HP affinely_persistently_if_elim.
Qed.
Global Instance into_wand_impl_false_false P Q P' :
  Absorbing P' → Absorbing (P' → Q) →
  FromAssumption false P P' → IntoWand false false (P' → Q) P Q.
Proof.
  rewrite /FromAssumption /IntoWand /= => ?? ->. apply wand_intro_r.
  by rewrite sep_and impl_elim_l.
Qed.
Global Instance into_wand_impl_false_true P Q P' :
  Absorbing P' → FromAssumption true P P' →
  IntoWand false true (P' → Q) P Q.
Proof.
  rewrite /IntoWand /FromAssumption /= => ? HP. apply wand_intro_l.
  rewrite -(affinely_persistently_idemp P) HP.
  by rewrite -persistently_and_affinely_sep_l persistently_elim impl_elim_r.
Qed.
Global Instance into_wand_impl_true_false P Q P' :
  Affine P' → FromAssumption false P P' →
  IntoWand true false (P' → Q) P Q.
Proof.
  rewrite /FromAssumption /IntoWand /= => ? HP. apply wand_intro_r.
  rewrite -persistently_and_affinely_sep_l HP -{2}(affine_affinely P') -affinely_and_lr.
  by rewrite affinely_persistently_elim impl_elim_l.
Qed.
Global Instance into_wand_impl_true_true P Q P' :
  FromAssumption true P P' → IntoWand true true (P' → Q) P Q.
Proof.
  rewrite /FromAssumption /IntoWand /= => <-. apply wand_intro_l.
  rewrite -{1}(affinely_persistently_idemp P) -and_sep_affinely_persistently.
  by rewrite -affinely_persistently_and impl_elim_r affinely_persistently_elim.
Qed.

Global Instance into_wand_and_l p q R1 R2 P' Q' :
  IntoWand p q R1 P' Q' → IntoWand p q (R1 ∧ R2) P' Q'.
Proof. rewrite /IntoWand=> ?. by rewrite /bi_wand_iff and_elim_l. Qed.
Global Instance into_wand_and_r p q R1 R2 P' Q' :
  IntoWand p q R2 Q' P' → IntoWand p q (R1 ∧ R2) Q' P'.
Proof. rewrite /IntoWand=> ?. by rewrite /bi_wand_iff and_elim_r. Qed.

Global Instance into_wand_forall_prop_true p (φ : Prop) P :
  IntoWand p true (∀ _ : φ, P) ⌜ φ ⌝ P.
Proof.
  rewrite /IntoWand (affinely_persistently_if_elim p) /=
          -impl_wand_affinely_persistently -pure_impl_forall
          bi.persistently_elim //.
Qed.
Global Instance into_wand_forall_prop_false p (φ : Prop) P :
  Absorbing P → IntoWand p false (∀ _ : φ, P) ⌜ φ ⌝ P.
Proof.
  intros ?.
  rewrite /IntoWand (affinely_persistently_if_elim p) /= pure_wand_forall //.
Qed.

Global Instance into_wand_forall {A} p q (Φ : A → PROP) P Q x :
  IntoWand p q (Φ x) P Q → IntoWand p q (∀ x, Φ x) P Q.
Proof. rewrite /IntoWand=> <-. by rewrite (forall_elim x). Qed.

Global Instance into_wand_affinely_persistently p q R P Q :
  IntoWand p q R P Q → IntoWand p q (□ R) P Q.
Proof. by rewrite /IntoWand affinely_persistently_elim. Qed.
Global Instance into_wand_persistently_true q R P Q :
  IntoWand true q R P Q → IntoWand true q (bi_persistently R) P Q.
Proof. by rewrite /IntoWand /= persistently_idemp. Qed.
Global Instance into_wand_persistently_false `{!BiAffine PROP} q R P Q :
  IntoWand false q R P Q → IntoWand false q (bi_persistently R) P Q.
Proof. by rewrite /IntoWand persistently_elim. Qed.
Global Instance into_wand_embed `{BiEmbed PROP PROP'} p q R P Q :
  IntoWand p q R P Q → IntoWand p q ⎡R⎤ ⎡P⎤ ⎡Q⎤.
Proof.
  rewrite /IntoWand -!embed_persistently_if -!embed_affinely_if
          -embed_wand => -> //.
Qed.

(* FromWand *)
Global Instance from_wand_wand P1 P2 : FromWand (P1 -∗ P2) P1 P2.
Proof. by rewrite /FromWand. Qed.
Global Instance from_wand_embed `{BiEmbed PROP PROP'} P Q1 Q2 :
  FromWand P Q1 Q2 → FromWand ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof. by rewrite /FromWand -embed_wand => <-. Qed.

(* FromImpl *)
Global Instance from_impl_impl P1 P2 : FromImpl (P1 → P2) P1 P2.
Proof. by rewrite /FromImpl. Qed.
Global Instance from_impl_embed `{BiEmbed PROP PROP'} P Q1 Q2 :
  FromImpl P Q1 Q2 → FromImpl ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof. by rewrite /FromImpl -embed_impl => <-. Qed.

(* FromAnd *)
Global Instance from_and_and P1 P2 : FromAnd (P1 ∧ P2) P1 P2 | 100.
Proof. by rewrite /FromAnd. Qed.
Global Instance from_and_sep_persistent_l P1 P1' P2 :
  FromAffinely P1 P1' → Persistent P1' → FromAnd (P1 ∗ P2) P1' P2 | 9.
Proof.
  rewrite /FromAffinely /FromAnd=> <- ?. by rewrite persistent_and_affinely_sep_l_1.
Qed.
Global Instance from_and_sep_persistent_r P1 P2 P2' :
  FromAffinely P2 P2' → Persistent P2' → FromAnd (P1 ∗ P2) P1 P2' | 10.
Proof.
  rewrite /FromAffinely /FromAnd=> <- ?. by rewrite persistent_and_affinely_sep_r_1.
Qed.
Global Instance from_and_sep_persistent P1 P2 :
  Persistent P1 → Persistent P2 → FromAnd (P1 ∗ P2) P1 P2 | 11.
Proof.
  rewrite /FromAffinely /FromAnd. intros ??. by rewrite -persistent_and_sep_1.
Qed.

Global Instance from_and_pure φ ψ : @FromAnd PROP ⌜φ ∧ ψ⌝ ⌜φ⌝ ⌜ψ⌝.
Proof. by rewrite /FromAnd pure_and. Qed.

Global Instance from_and_persistently P Q1 Q2 :
  FromAnd P Q1 Q2 →
  FromAnd (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2).
Proof. rewrite /FromAnd=> <-. by rewrite persistently_and. Qed.
Global Instance from_and_persistently_sep P Q1 Q2 :
  FromSep P Q1 Q2 →
  FromAnd (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2) | 11.
Proof. rewrite /FromAnd=> <-. by rewrite -persistently_and persistently_and_sep. Qed.

Global Instance from_and_embed `{BiEmbed PROP PROP'} P Q1 Q2 :
  FromAnd P Q1 Q2 → FromAnd ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof. by rewrite /FromAnd -embed_and => <-. Qed.

Global Instance from_and_big_sepL_cons_persistent {A} (Φ : nat → A → PROP) x l :
  Persistent (Φ 0 x) →
  FromAnd ([∗ list] k ↦ y ∈ x :: l, Φ k y) (Φ 0 x) ([∗ list] k ↦ y ∈ l, Φ (S k) y).
Proof. intros. by rewrite /FromAnd big_opL_cons persistent_and_sep_1. Qed.
Global Instance from_and_big_sepL_app_persistent {A} (Φ : nat → A → PROP) l1 l2 :
  (∀ k y, Persistent (Φ k y)) →
  FromAnd ([∗ list] k ↦ y ∈ l1 ++ l2, Φ k y)
    ([∗ list] k ↦ y ∈ l1, Φ k y) ([∗ list] k ↦ y ∈ l2, Φ (length l1 + k) y).
Proof. intros. by rewrite /FromAnd big_opL_app persistent_and_sep_1. Qed.

(* FromSep *)
Global Instance from_sep_sep P1 P2 : FromSep (P1 ∗ P2) P1 P2 | 100.
Proof. by rewrite /FromSep. Qed.
Global Instance from_sep_and P1 P2 :
  TCOr (Affine P1) (Absorbing P2) → TCOr (Absorbing P1) (Affine P2) →
  FromSep (P1 ∧ P2) P1 P2 | 101.
Proof. intros. by rewrite /FromSep sep_and. Qed.

Global Instance from_sep_pure φ ψ : @FromSep PROP ⌜φ ∧ ψ⌝ ⌜φ⌝ ⌜ψ⌝.
Proof. by rewrite /FromSep pure_and sep_and. Qed.

Global Instance from_sep_affinely P Q1 Q2 :
  FromSep P Q1 Q2 → FromSep (bi_affinely P) (bi_affinely Q1) (bi_affinely Q2).
Proof. rewrite /FromSep=> <-. by rewrite affinely_sep_2. Qed.
Global Instance from_sep_absorbingly P Q1 Q2 :
  FromSep P Q1 Q2 → FromSep (bi_absorbingly P) (bi_absorbingly Q1) (bi_absorbingly Q2).
Proof. rewrite /FromSep=> <-. by rewrite absorbingly_sep. Qed.
Global Instance from_sep_persistently P Q1 Q2 :
  FromSep P Q1 Q2 →
  FromSep (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2).
Proof. rewrite /FromSep=> <-. by rewrite persistently_sep_2. Qed.

Global Instance from_sep_embed `{BiEmbed PROP PROP'} P Q1 Q2 :
  FromSep P Q1 Q2 → FromSep ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof. by rewrite /FromSep -embed_sep => <-. Qed.

Global Instance from_sep_big_sepL_cons {A} (Φ : nat → A → PROP) x l :
  FromSep ([∗ list] k ↦ y ∈ x :: l, Φ k y) (Φ 0 x) ([∗ list] k ↦ y ∈ l, Φ (S k) y).
Proof. by rewrite /FromSep big_sepL_cons. Qed.
Global Instance from_sep_big_sepL_app {A} (Φ : nat → A → PROP) l1 l2 :
  FromSep ([∗ list] k ↦ y ∈ l1 ++ l2, Φ k y)
    ([∗ list] k ↦ y ∈ l1, Φ k y) ([∗ list] k ↦ y ∈ l2, Φ (length l1 + k) y).
Proof. by rewrite /FromSep big_opL_app. Qed.

(* IntoAnd *)
Global Instance into_and_and p P Q : IntoAnd p (P ∧ Q) P Q | 10.
Proof. by rewrite /IntoAnd affinely_persistently_if_and. Qed.
Global Instance into_and_and_affine_l P Q Q' :
  Affine P → FromAffinely Q' Q → IntoAnd false (P ∧ Q) P Q'.
Proof.
  intros. rewrite /IntoAnd /=.
  by rewrite -(affine_affinely P) affinely_and_l affinely_and (from_affinely Q').
Qed.
Global Instance into_and_and_affine_r P P' Q :
  Affine Q → FromAffinely P' P → IntoAnd false (P ∧ Q) P' Q.
Proof.
  intros. rewrite /IntoAnd /=.
  by rewrite -(affine_affinely Q) affinely_and_r affinely_and (from_affinely P').
Qed.

Global Instance into_and_sep `{BiPositive PROP} P Q : IntoAnd true (P ∗ Q) P Q.
Proof.
  by rewrite /IntoAnd /= persistently_sep -and_sep_persistently persistently_and.
Qed.
Global Instance into_and_sep_affine P Q :
  TCOr (Affine P) (Absorbing Q) → TCOr (Absorbing P) (Affine Q) →
  IntoAnd true (P ∗ Q) P Q.
Proof. intros. by rewrite /IntoAnd /= sep_and. Qed.

Global Instance into_and_pure p φ ψ : @IntoAnd PROP p ⌜φ ∧ ψ⌝ ⌜φ⌝ ⌜ψ⌝.
Proof. by rewrite /IntoAnd pure_and affinely_persistently_if_and. Qed.

Global Instance into_and_affinely p P Q1 Q2 :
  IntoAnd p P Q1 Q2 → IntoAnd p (bi_affinely P) (bi_affinely Q1) (bi_affinely Q2).
Proof.
  rewrite /IntoAnd. destruct p; simpl.
  - by rewrite -affinely_and !persistently_affinely.
  - intros ->. by rewrite affinely_and.
Qed.
Global Instance into_and_persistently p P Q1 Q2 :
  IntoAnd p P Q1 Q2 →
  IntoAnd p (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2).
Proof.
  rewrite /IntoAnd /=. destruct p; simpl.
  - by rewrite -persistently_and !persistently_idemp.
  - intros ->. by rewrite persistently_and.
Qed.
Global Instance into_and_embed `{BiEmbed PROP PROP'} p P Q1 Q2 :
  IntoAnd p P Q1 Q2 → IntoAnd p ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof.
  rewrite /IntoAnd -embed_and -!embed_persistently_if
          -!embed_affinely_if=> -> //.
Qed.

(* IntoSep *)
Global Instance into_sep_sep P Q : IntoSep (P ∗ Q) P Q.
Proof. by rewrite /IntoSep. Qed.

Inductive AndIntoSep : PROP → PROP → PROP → PROP → Prop :=
  | and_into_sep_affine P Q Q' : Affine P → FromAffinely Q' Q → AndIntoSep P P Q Q'
  | and_into_sep P Q : AndIntoSep P (bi_affinely P)%I Q Q.
Existing Class AndIntoSep.
Global Existing Instance and_into_sep_affine | 0.
Global Existing Instance and_into_sep | 2.

Global Instance into_sep_and_persistent_l P P' Q Q' :
  Persistent P → AndIntoSep P P' Q Q' → IntoSep (P ∧ Q) P' Q'.
Proof.
  destruct 2 as [P Q Q'|P Q]; rewrite /IntoSep.
  - rewrite -(from_affinely Q') -(affine_affinely P) affinely_and_lr.
    by rewrite persistent_and_affinely_sep_l_1.
  - by rewrite persistent_and_affinely_sep_l_1.
Qed.
Global Instance into_sep_and_persistent_r P P' Q Q' :
  Persistent Q → AndIntoSep Q Q' P P' → IntoSep (P ∧ Q) P' Q'.
Proof.
  destruct 2 as [Q P P'|Q P]; rewrite /IntoSep.
  - rewrite -(from_affinely P') -(affine_affinely Q) -affinely_and_lr.
    by rewrite persistent_and_affinely_sep_r_1.
  - by rewrite persistent_and_affinely_sep_r_1.
Qed.

Global Instance into_sep_pure φ ψ : @IntoSep PROP ⌜φ ∧ ψ⌝ ⌜φ⌝ ⌜ψ⌝.
Proof. by rewrite /IntoSep pure_and persistent_and_sep_1. Qed.

Global Instance into_sep_embed `{BiEmbed PROP PROP'} P Q1 Q2 :
  IntoSep P Q1 Q2 → IntoSep ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof. rewrite /IntoSep -embed_sep=> -> //. Qed.

Global Instance into_sep_affinely `{BiPositive PROP} P Q1 Q2 :
  IntoSep P Q1 Q2 → IntoSep (bi_affinely P) (bi_affinely Q1) (bi_affinely Q2) | 0.
Proof. rewrite /IntoSep /= => ->. by rewrite affinely_sep. Qed.
(* FIXME: This instance is kind of strange, it just gets rid of the bi_affinely.
Also, it overlaps with `into_sep_affinely_later`, and hence has lower
precedence. *)
Global Instance into_sep_affinely_trim P Q1 Q2 :
  IntoSep P Q1 Q2 → IntoSep (bi_affinely P) Q1 Q2 | 20.
Proof. rewrite /IntoSep /= => ->. by rewrite affinely_elim. Qed.

Global Instance into_sep_persistently `{BiPositive PROP} P Q1 Q2 :
  IntoSep P Q1 Q2 →
  IntoSep (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2).
Proof. rewrite /IntoSep /= => ->. by rewrite persistently_sep. Qed.
Global Instance into_sep_persistently_affine P Q1 Q2 :
  IntoSep P Q1 Q2 →
  TCOr (Affine Q1) (Absorbing Q2) → TCOr (Absorbing Q1) (Affine Q2) →
  IntoSep (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2).
Proof.
  rewrite /IntoSep /= => -> ??.
  by rewrite sep_and persistently_and persistently_and_sep_l_1.
Qed.
Global Instance into_sep_affinely_persistently_affine P Q1 Q2 :
  IntoSep P Q1 Q2 →
  TCOr (Affine Q1) (Absorbing Q2) → TCOr (Absorbing Q1) (Affine Q2) →
  IntoSep (□ P) (□ Q1) (□ Q2).
Proof.
  rewrite /IntoSep /= => -> ??.
  by rewrite sep_and affinely_persistently_and and_sep_affinely_persistently.
Qed.

(* We use [IsCons] and [IsApp] to make sure that [frame_big_sepL_cons] and
[frame_big_sepL_app] cannot be applied repeatedly often when having
[ [∗ list] k ↦ x ∈ ?e, Φ k x] with [?e] an evar. *)
Global Instance into_sep_big_sepL_cons {A} (Φ : nat → A → PROP) l x l' :
  IsCons l x l' →
  IntoSep ([∗ list] k ↦ y ∈ l, Φ k y)
    (Φ 0 x) ([∗ list] k ↦ y ∈ l', Φ (S k) y).
Proof. rewrite /IsCons=>->. by rewrite /IntoSep big_sepL_cons. Qed.
Global Instance into_sep_big_sepL_app {A} (Φ : nat → A → PROP) l l1 l2 :
  IsApp l l1 l2 →
  IntoSep ([∗ list] k ↦ y ∈ l, Φ k y)
    ([∗ list] k ↦ y ∈ l1, Φ k y) ([∗ list] k ↦ y ∈ l2, Φ (length l1 + k) y).
Proof. rewrite /IsApp=>->. by rewrite /IntoSep big_sepL_app. Qed.

(* FromOr *)
Global Instance from_or_or P1 P2 : FromOr (P1 ∨ P2) P1 P2.
Proof. by rewrite /FromOr. Qed.
Global Instance from_or_pure φ ψ : @FromOr PROP ⌜φ ∨ ψ⌝ ⌜φ⌝ ⌜ψ⌝.
Proof. by rewrite /FromOr pure_or. Qed.
Global Instance from_or_affinely P Q1 Q2 :
  FromOr P Q1 Q2 → FromOr (bi_affinely P) (bi_affinely Q1) (bi_affinely Q2).
Proof. rewrite /FromOr=> <-. by rewrite affinely_or. Qed.
Global Instance from_or_absorbingly P Q1 Q2 :
  FromOr P Q1 Q2 → FromOr (bi_absorbingly P) (bi_absorbingly Q1) (bi_absorbingly Q2).
Proof. rewrite /FromOr=> <-. by rewrite absorbingly_or. Qed.
Global Instance from_or_persistently P Q1 Q2 :
  FromOr P Q1 Q2 →
  FromOr (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2).
Proof. rewrite /FromOr=> <-. by rewrite persistently_or. Qed.
Global Instance from_or_embed `{BiEmbed PROP PROP'} P Q1 Q2 :
  FromOr P Q1 Q2 → FromOr ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof. by rewrite /FromOr -embed_or => <-. Qed.

(* IntoOr *)
Global Instance into_or_or P Q : IntoOr (P ∨ Q) P Q.
Proof. by rewrite /IntoOr. Qed.
Global Instance into_or_pure φ ψ : @IntoOr PROP ⌜φ ∨ ψ⌝ ⌜φ⌝ ⌜ψ⌝.
Proof. by rewrite /IntoOr pure_or. Qed.
Global Instance into_or_affinely P Q1 Q2 :
  IntoOr P Q1 Q2 → IntoOr (bi_affinely P) (bi_affinely Q1) (bi_affinely Q2).
Proof. rewrite /IntoOr=>->. by rewrite affinely_or. Qed.
Global Instance into_or_absorbingly P Q1 Q2 :
  IntoOr P Q1 Q2 → IntoOr (bi_absorbingly P) (bi_absorbingly Q1) (bi_absorbingly Q2).
Proof. rewrite /IntoOr=>->. by rewrite absorbingly_or. Qed.
Global Instance into_or_persistently P Q1 Q2 :
  IntoOr P Q1 Q2 →
  IntoOr (bi_persistently P) (bi_persistently Q1) (bi_persistently Q2).
Proof. rewrite /IntoOr=>->. by rewrite persistently_or. Qed.
Global Instance into_or_embed `{BiEmbed PROP PROP'} P Q1 Q2 :
  IntoOr P Q1 Q2 → IntoOr ⎡P⎤ ⎡Q1⎤ ⎡Q2⎤.
Proof. by rewrite /IntoOr -embed_or => <-. Qed.

(* FromExist *)
Global Instance from_exist_exist {A} (Φ : A → PROP): FromExist (∃ a, Φ a) Φ.
Proof. by rewrite /FromExist. Qed.
Global Instance from_exist_pure {A} (φ : A → Prop) :
  @FromExist PROP A ⌜∃ x, φ x⌝ (λ a, ⌜φ a⌝)%I.
Proof. by rewrite /FromExist pure_exist. Qed.
Global Instance from_exist_affinely {A} P (Φ : A → PROP) :
  FromExist P Φ → FromExist (bi_affinely P) (λ a, bi_affinely (Φ a))%I.
Proof. rewrite /FromExist=> <-. by rewrite affinely_exist. Qed.
Global Instance from_exist_absorbingly {A} P (Φ : A → PROP) :
  FromExist P Φ → FromExist (bi_absorbingly P) (λ a, bi_absorbingly (Φ a))%I.
Proof. rewrite /FromExist=> <-. by rewrite absorbingly_exist. Qed.
Global Instance from_exist_persistently {A} P (Φ : A → PROP) :
  FromExist P Φ → FromExist (bi_persistently P) (λ a, bi_persistently (Φ a))%I.
Proof. rewrite /FromExist=> <-. by rewrite persistently_exist. Qed.
Global Instance from_exist_embed `{BiEmbed PROP PROP'} {A} P (Φ : A → PROP) :
  FromExist P Φ → FromExist ⎡P⎤ (λ a, ⎡Φ a⎤%I).
Proof. by rewrite /FromExist -embed_exist => <-. Qed.

(* IntoExist *)
Global Instance into_exist_exist {A} (Φ : A → PROP) : IntoExist (∃ a, Φ a) Φ.
Proof. by rewrite /IntoExist. Qed.
Global Instance into_exist_pure {A} (φ : A → Prop) :
  @IntoExist PROP A ⌜∃ x, φ x⌝ (λ a, ⌜φ a⌝)%I.
Proof. by rewrite /IntoExist pure_exist. Qed.
Global Instance into_exist_affinely {A} P (Φ : A → PROP) :
  IntoExist P Φ → IntoExist (bi_affinely P) (λ a, bi_affinely (Φ a))%I.
Proof. rewrite /IntoExist=> HP. by rewrite HP affinely_exist. Qed.
Global Instance into_exist_and_pure P Q φ :
  IntoPureT P φ → IntoExist (P ∧ Q) (λ _ : φ, Q).
Proof.
  intros (φ'&->&?). rewrite /IntoExist (into_pure P).
  apply pure_elim_l=> Hφ. by rewrite -(exist_intro Hφ).
Qed.
Global Instance into_exist_sep_pure P Q φ :
  IntoPureT P φ → TCOr (Affine P) (Absorbing Q) → IntoExist (P ∗ Q) (λ _ : φ, Q).
Proof.
  intros (φ'&->&?) ?. rewrite /IntoExist.
  eapply (pure_elim φ'); [by rewrite (into_pure P); apply sep_elim_l, _|]=>?.
  rewrite -exist_intro //. apply sep_elim_r, _.
Qed.
Global Instance into_exist_absorbingly {A} P (Φ : A → PROP) :
  IntoExist P Φ → IntoExist (bi_absorbingly P) (λ a, bi_absorbingly (Φ a))%I.
Proof. rewrite /IntoExist=> HP. by rewrite HP absorbingly_exist. Qed.
Global Instance into_exist_persistently {A} P (Φ : A → PROP) :
  IntoExist P Φ → IntoExist (bi_persistently P) (λ a, bi_persistently (Φ a))%I.
Proof. rewrite /IntoExist=> HP. by rewrite HP persistently_exist. Qed.
Global Instance into_exist_embed `{BiEmbed PROP PROP'} {A} P (Φ : A → PROP) :
  IntoExist P Φ → IntoExist ⎡P⎤ (λ a, ⎡Φ a⎤%I).
Proof. by rewrite /IntoExist -embed_exist => <-. Qed.

(* IntoForall *)
Global Instance into_forall_forall {A} (Φ : A → PROP) : IntoForall (∀ a, Φ a) Φ.
Proof. by rewrite /IntoForall. Qed.
Global Instance into_forall_affinely {A} P (Φ : A → PROP) :
  IntoForall P Φ → IntoForall (bi_affinely P) (λ a, bi_affinely (Φ a))%I.
Proof. rewrite /IntoForall=> HP. by rewrite HP affinely_forall. Qed.
Global Instance into_forall_persistently {A} P (Φ : A → PROP) :
  IntoForall P Φ → IntoForall (bi_persistently P) (λ a, bi_persistently (Φ a))%I.
Proof. rewrite /IntoForall=> HP. by rewrite HP persistently_forall. Qed.
Global Instance into_forall_embed `{BiEmbed PROP PROP'} {A} P (Φ : A → PROP) :
  IntoForall P Φ → IntoForall ⎡P⎤ (λ a, ⎡Φ a⎤%I).
Proof. by rewrite /IntoForall -embed_forall => <-. Qed.

(* FromForall *)
Global Instance from_forall_forall {A} (Φ : A → PROP) :
  FromForall (∀ x, Φ x)%I Φ.
Proof. by rewrite /FromForall. Qed.
Global Instance from_forall_pure {A} (φ : A → Prop) :
  @FromForall PROP A (⌜∀ a : A, φ a⌝)%I (λ a, ⌜ φ a ⌝)%I.
Proof. by rewrite /FromForall pure_forall. Qed.
Global Instance from_forall_pure_not (φ : Prop) :
  @FromForall PROP φ (⌜¬ φ⌝)%I (λ a : φ, False)%I.
Proof. by rewrite /FromForall pure_forall. Qed.
Global Instance from_forall_impl_pure P Q φ :
  IntoPureT P φ → FromForall (P → Q)%I (λ _ : φ, Q)%I.
Proof.
  intros (φ'&->&?). by rewrite /FromForall -pure_impl_forall (into_pure P).
Qed.
Global Instance from_forall_wand_pure P Q φ :
  IntoPureT P φ → TCOr (Affine P) (Absorbing Q) →
  FromForall (P -∗ Q)%I (λ _ : φ, Q)%I.
Proof.
  intros (φ'&->&?) [|]; rewrite /FromForall; apply wand_intro_r.
  - rewrite -(affine_affinely P) (into_pure P) -persistent_and_affinely_sep_r.
    apply pure_elim_r=>?. by rewrite forall_elim.
  - by rewrite (into_pure P) -pure_wand_forall wand_elim_l.
Qed.

Global Instance from_forall_affinely `{BiAffine PROP} {A} P (Φ : A → PROP) :
  FromForall P Φ → FromForall (bi_affinely P)%I (λ a, bi_affinely (Φ a))%I.
Proof.
  rewrite /FromForall=> <-. rewrite affine_affinely. by setoid_rewrite affinely_elim.
Qed.
Global Instance from_forall_persistently {A} P (Φ : A → PROP) :
  FromForall P Φ → FromForall (bi_persistently P)%I (λ a, bi_persistently (Φ a))%I.
Proof. rewrite /FromForall=> <-. by rewrite persistently_forall. Qed.
Global Instance from_forall_embed `{BiEmbed PROP PROP'} {A} P (Φ : A → PROP) :