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+Require Export iris.model.
+
+Definition inv {Σ} (i : positive) (P : iProp Σ) : iProp Σ :=
+  uPred_own (Res {[ i ↦ to_agree (Later (iProp_unfold P)) ]} ∅ ∅).
+Arguments inv {_} _ _%I.
+Definition ownP {Σ} (σ : istate Σ) : iProp Σ := uPred_own (Res ∅ (Excl σ) ∅).
+Definition ownG {Σ} (m : icmra' Σ) : iProp Σ := uPred_own (Res ∅ ∅ m).
+Instance: Params (@inv) 2.
+Instance: Params (@ownP) 1.
+Instance: Params (@ownG) 1.
+
+Section ownership.
+Context {Σ : iParam}.
+Implicit Types r : res' Σ.
+Implicit Types P : iProp Σ.
+Implicit Types m : icmra' Σ.
+
+(* Invariants *)
+Global Instance inv_contractive i : Contractive (@inv Σ i).
+Proof.
+  intros n P Q HPQ.
+  apply (_: Proper (_ ==> _) iProp_unfold), Later_contractive in HPQ.
+  by unfold inv; rewrite HPQ.
+Qed.
+Lemma inv_duplicate i P : inv i P ≡ (inv i P ★ inv i P)%I.
+Proof.
+  by rewrite /inv -uPred.own_op Res_op
+    map_op_singleton agree_idempotent !(left_id _ _).
+Qed.
+Lemma always_inv i P : (□ inv i P)%I ≡ inv i P.
+Proof.
+  by apply uPred.always_own; rewrite Res_unit !ra_unit_empty map_unit_singleton.
+Qed.
+
+(* physical state *)
+Lemma ownP_twice σ1 σ2 : (ownP σ1 ★ ownP σ2 : iProp Σ) ⊑ False.
+Proof.
+  rewrite /ownP -uPred.own_op Res_op.
+  by apply uPred.own_invalid; intros (_&?&_).
+Qed.
+
+(* ghost state *)
+Global Instance ownG_ne n : Proper (dist n ==> dist n) (@ownG Σ).
+Proof. by intros m m' Hm; unfold ownG; rewrite Hm. Qed.
+Global Instance ownG_proper : Proper ((≡) ==> (≡)) (@ownG Σ) := ne_proper _.
+Lemma ownG_op m1 m2 : ownG (m1 ⋅ m2) ≡ (ownG m1 ★ ownG m2)%I.
+Proof. by rewrite /ownG -uPred.own_op Res_op !(left_id _ _). Qed.
+Lemma always_ownG_unit m : (□ ownG (unit m))%I ≡ ownG (unit m).
+Proof.
+  by apply uPred.always_own; rewrite Res_unit !ra_unit_empty ra_unit_idempotent.
+Qed.
+Lemma ownG_valid m : (ownG m) ⊑ (✓ m).
+Proof. by rewrite /ownG uPred.own_valid; apply uPred.valid_mono=> n [? []]. Qed.
+
+(* inversion lemmas *)
+Lemma inv_spec r n i P :
+  ✓{n} r →
+  (inv i P) n r ↔ wld r !! i ={n}= Some (to_agree (Later (iProp_unfold P))).
+Proof.
+  intros [??]; rewrite /uPred_holds/=res_includedN/=singleton_includedN; split.
+  * intros [(P'&Hi&HP) _]; rewrite Hi.
+    by apply Some_dist, symmetry, agree_valid_includedN,
+      (cmra_included_includedN _ P'),HP; apply map_lookup_validN with (wld r) i.
+  * intros ?; split_ands; try apply cmra_empty_least; eauto.
+Qed.
+Lemma ownG_spec r n m : (ownG m) n r ↔ m ≼{n} gst r.
+Proof.
+  rewrite /uPred_holds /= res_includedN; naive_solver (apply cmra_empty_least).
+Qed.
+End ownership.