logic.v 16 KB
 Robbert Krebbers committed Nov 11, 2015 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 ``````Require Import cmra cofe_instances. Local Hint Extern 1 (_ ≼ _) => etransitivity; [eassumption|]. Local Hint Extern 1 (_ ≼ _) => etransitivity; [|eassumption]. Local Hint Extern 10 (_ ≤ _) => omega. Structure iProp (A : cmraT) : Type := IProp { iprop_holds :> nat → A -> Prop; iprop_ne x1 x2 n : iprop_holds n x1 → x1 ={n}= x2 → iprop_holds n x2; iprop_weaken x1 x2 n1 n2 : x1 ≼ x2 → n2 ≤ n1 → validN n2 x2 → iprop_holds n1 x1 → iprop_holds n2 x2 }. Add Printing Constructor iProp. Instance: Params (@iprop_holds) 3. Instance iprop_equiv (A : cmraT) : Equiv (iProp A) := λ P Q, ∀ x n, validN n x → P n x ↔ Q n x. Instance iprop_dist (A : cmraT) : Dist (iProp A) := λ n P Q, ∀ x n', n' < n → validN n' x → P n' x ↔ Q n' x. Program Instance iprop_compl (A : cmraT) : Compl (iProp A) := λ c, {| iprop_holds n x := c (S n) n x |}. Next Obligation. by intros A c x y n ??; simpl in *; apply iprop_ne with x. Qed. Next Obligation. intros A c x1 x2 n1 n2 ????; simpl in *. apply (chain_cauchy c (S n2) (S n1)); eauto using iprop_weaken, cmra_valid_le. Qed. Instance iprop_cofe (A : cmraT) : Cofe (iProp A). Proof. split. * intros P Q; split; [by intros HPQ n x i ??; apply HPQ|]. intros HPQ x n ?; apply HPQ with (S n); auto. * intros n; split. + by intros P x i. + by intros P Q HPQ x i ??; symmetry; apply HPQ. + by intros P Q Q' HP HQ x i ??; transitivity (Q i x); [apply HP|apply HQ]. * intros n P Q HPQ x i ??; apply HPQ; auto. * intros P Q x i ??; lia. * intros c n x i ??; apply (chain_cauchy c (S i) n); auto. Qed. Instance iprop_holds_ne {A} (P : iProp A) n : Proper (dist n ==> iff) (P n). Proof. intros x1 x2 Hx; split; eauto using iprop_ne. Qed. Instance iprop_holds_proper {A} (P : iProp A) n : Proper ((≡) ==> iff) (P n). Proof. by intros x1 x2 Hx; apply iprop_holds_ne, equiv_dist. Qed. Definition iPropC (A : cmraT) : cofeT := CofeT (iProp A). (** functor *) Program Definition iProp_map {A B : cmraT} (f: B -n> A) `{!CMRAPreserving f} (P : iProp A) : iProp B := {| iprop_holds n x := P n (f x) |}. Next Obligation. by intros A B f ? P y1 y2 n ? Hy; simpl; rewrite <-Hy. Qed. Next Obligation. by intros A B f ? P y1 y2 n i ???; simpl; apply iprop_weaken; auto; apply validN_preserving || apply included_preserving. Qed. (** logical entailement *) Instance iprop_entails {A} : SubsetEq (iProp A) := λ P Q, ∀ x n, validN n x → P n x → Q n x. (** logical connectives *) Program Definition iprop_const {A} (P : Prop) : iProp A := {| iprop_holds n x := P |}. Solve Obligations with done. Program Definition iprop_and {A} (P Q : iProp A) : iProp A := {| iprop_holds n x := P n x ∧ Q n x |}. Solve Obligations with naive_solver eauto 2 using iprop_ne, iprop_weaken. Program Definition iprop_or {A} (P Q : iProp A) : iProp A := {| iprop_holds n x := P n x ∨ Q n x |}. Solve Obligations with naive_solver eauto 2 using iprop_ne, iprop_weaken. Program Definition iprop_impl {A} (P Q : iProp A) : iProp A := {| iprop_holds n x := ∀ x' n', x ≼ x' → n' ≤ n → validN n' x' → P n' x' → Q n' x' |}. Next Obligation. intros A P Q x1' x1 n1 HPQ Hx1 x2 n2 ????. destruct (cmra_included_dist_l x1 x2 x1' n1) as (x2'&?&Hx2); auto. assert (x2' ={n2}= x2) as Hx2' by (by apply dist_le with n1). assert (validN n2 x2') by (by rewrite Hx2'); rewrite <-Hx2'. by apply HPQ, iprop_weaken with x2' n2, iprop_ne with x2. Qed. Next Obligation. naive_solver eauto 2 with lia. Qed. Program Definition iprop_forall {A B} (P : A → iProp B) : iProp B := {| iprop_holds n x := ∀ a, P a n x |}. Solve Obligations with naive_solver eauto 2 using iprop_ne, iprop_weaken. Program Definition iprop_exist {A B} (P : A → iProp B) : iProp B := {| iprop_holds n x := ∃ a, P a n x |}. Solve Obligations with naive_solver eauto 2 using iprop_ne, iprop_weaken. Program Definition iprop_eq {A} {B : cofeT} (b1 b2 : B) : iProp A := {| iprop_holds n x := b1 ={n}= b2 |}. Solve Obligations with naive_solver eauto 2 using (dist_le (A:=B)). Program Definition iprop_sep {A} (P Q : iProp A) : iProp A := {| iprop_holds n x := ∃ x1 x2, x ={n}= x1 ⋅ x2 ∧ P n x1 ∧ Q n x2 |}. Next Obligation. `````` Robbert Krebbers committed Nov 11, 2015 95 `````` by intros A P Q x y n (x1&x2&?&?&?) Hxy; exists x1, x2; rewrite <-Hxy. `````` Robbert Krebbers committed Nov 11, 2015 96 97 98 99 100 101 102 ``````Qed. Next Obligation. intros A P Q x y n1 n2 Hxy ?? (x1&x2&Hx&?&?). assert (∃ x2', y ={n2}= x1 ⋅ x2' ∧ x2 ≼ x2') as (x2'&Hy&?). { rewrite ra_included_spec in Hxy; destruct Hxy as [z Hy]. exists (x2 ⋅ z); split; eauto using ra_included_l. apply dist_le with n1; auto. by rewrite (associative op), <-Hx, Hy. } `````` Robbert Krebbers committed Nov 11, 2015 103 `````` exists x1, x2'; split_ands; auto. `````` Robbert Krebbers committed Nov 11, 2015 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 `````` * apply iprop_weaken with x1 n1; auto. by apply cmra_valid_op_l with x2'; rewrite <-Hy. * apply iprop_weaken with x2 n1; auto. by apply cmra_valid_op_r with x1; rewrite <-Hy. Qed. Program Definition iprop_wand {A} (P Q : iProp A) : iProp A := {| iprop_holds n x := ∀ x' n', n' ≤ n → validN n' (x ⋅ x') → P n' x' → Q n' (x ⋅ x') |}. Next Obligation. intros A P Q x1 x2 n1 HPQ Hx x3 n2 ???; simpl in *. rewrite <-(dist_le _ _ _ _ Hx) by done; apply HPQ; auto. by rewrite (dist_le _ _ _ n2 Hx). Qed. Next Obligation. intros A P Q x1 x2 n1 n2 ??? HPQ x3 n3 ???; simpl in *. apply iprop_weaken with (x1 ⋅ x3) n3; auto using ra_preserving_r. apply HPQ; auto. apply cmra_valid_included with (x2 ⋅ x3); auto using ra_preserving_r. Qed. Program Definition iprop_later {A} (P : iProp A) : iProp A := {| iprop_holds n x := match n return _ with 0 => True | S n' => P n' x end |}. Next Obligation. intros A P ?? [|n]; eauto using iprop_ne,(dist_le (A:=A)). Qed. Next Obligation. intros A P x1 x2 [|n1] [|n2] ????; auto with lia. apply iprop_weaken with x1 n1; eauto using cmra_valid_S. Qed. Program Definition iprop_always {A} (P : iProp A) : iProp A := {| iprop_holds n x := P n (unit x) |}. Next Obligation. by intros A P x1 x2 n ? Hx; simpl in *; rewrite <-Hx. Qed. Next Obligation. intros A P x1 x2 n1 n2 ????; eapply iprop_weaken with (unit x1) n1; auto using ra_unit_preserving, cmra_unit_valid. Qed. Definition iprop_fixpoint {A} (P : iProp A → iProp A) `{!Contractive P} : iProp A := fixpoint P (iprop_const True). Delimit Scope iprop_scope with I. Bind Scope iprop_scope with iProp. Arguments iprop_holds {_} _%I _ _. Notation "'False'" := (iprop_const False) : iprop_scope. Notation "'True'" := (iprop_const True) : iprop_scope. Infix "∧" := iprop_and : iprop_scope. Infix "∨" := iprop_or : iprop_scope. Infix "→" := iprop_impl : iprop_scope. Infix "★" := iprop_sep (at level 80, right associativity) : iprop_scope. Infix "-★" := iprop_wand (at level 90) : iprop_scope. Notation "∀ x .. y , P" := (iprop_forall (λ x, .. (iprop_forall (λ y, P)) ..)) : iprop_scope. Notation "∃ x .. y , P" := (iprop_exist (λ x, .. (iprop_exist (λ y, P)) ..)) : iprop_scope. Notation "▷ P" := (iprop_later P) (at level 20) : iprop_scope. Notation "□ P" := (iprop_always P) (at level 20) : iprop_scope. Section logic. Context {A : cmraT}. Implicit Types P Q : iProp A. Global Instance iprop_preorder : PreOrder ((⊆) : relation (iProp A)). Proof. split. by intros P x i. by intros P Q Q' HP HQ x i ??; apply HQ, HP. Qed. Lemma iprop_equiv_spec P Q : P ≡ Q ↔ P ⊆ Q ∧ Q ⊆ P. Proof. split. * intros HPQ; split; intros x i; apply HPQ. * by intros [HPQ HQP]; intros x i ?; split; [apply HPQ|apply HQP]. Qed. (** Non-expansiveness *) Global Instance iprop_const_proper : Proper (iff ==> (≡)) (@iprop_const A). Proof. intros P Q HPQ ???; apply HPQ. Qed. Global Instance iprop_and_ne n : Proper (dist n ==> dist n ==> dist n) (@iprop_and A). Proof. intros P P' HP Q Q' HQ; split; intros [??]; split; by apply HP || by apply HQ. Qed. Global Instance iprop_or_ne n : Proper (dist n ==> dist n ==> dist n) (@iprop_or A). Proof. intros P P' HP Q Q' HQ; split; intros [?|?]; first [by left; apply HP | by right; apply HQ]. Qed. Global Instance iprop_impl_ne n : Proper (dist n ==> dist n ==> dist n) (@iprop_impl A). Proof. intros P P' HP Q Q' HQ; split; intros HPQ x' n'' ????; apply HQ,HPQ,HP; auto. Qed. Global Instance iprop_sep_ne n : Proper (dist n ==> dist n ==> dist n) (@iprop_sep A). Proof. intros P P' HP Q Q' HQ x n' ? Hx'; split; intros (x1&x2&Hx&?&?); `````` Robbert Krebbers committed Nov 11, 2015 197 `````` exists x1, x2; rewrite Hx in Hx'; split_ands; try apply HP; try apply HQ; `````` Robbert Krebbers committed Nov 11, 2015 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 `````` eauto using cmra_valid_op_l, cmra_valid_op_r. Qed. Global Instance iprop_wand_ne n : Proper (dist n ==> dist n ==> dist n) (@iprop_wand A). Proof. intros P P' HP Q Q' HQ x n' ??; split; intros HPQ x' n'' ???; apply HQ, HPQ, HP; eauto using cmra_valid_op_r. Qed. Global Instance iprop_eq_ne {B : cofeT} n : Proper (dist n ==> dist n ==> dist n) (@iprop_eq A B). Proof. intros x x' Hx y y' Hy z n'; split; intros; simpl in *. * by rewrite <-(dist_le _ _ _ _ Hx), <-(dist_le _ _ _ _ Hy) by auto. * by rewrite (dist_le _ _ _ _ Hx), (dist_le _ _ _ _ Hy) by auto. Qed. Global Instance iprop_forall_ne {B : cofeT} : Proper (pointwise_relation _ (dist n) ==> dist n) (@iprop_forall B A). Proof. by intros n P1 P2 HP12 x n'; split; intros HP a; apply HP12. Qed. Global Instance iprop_exists_ne {B : cofeT} : Proper (pointwise_relation _ (dist n) ==> dist n) (@iprop_exist B A). Proof. by intros n P1 P2 HP12 x n'; split; intros [a HP]; exists a; apply HP12. Qed. (** Introduction and elimination rules *) Lemma iprop_True_intro P : P ⊆ True%I. Proof. done. Qed. Lemma iprop_False_elim P : False%I ⊆ P. Proof. by intros x n ?. Qed. Lemma iprop_and_elim_l P Q : (P ∧ Q)%I ⊆ P. Proof. by intros x n ? [??]. Qed. Lemma iprop_and_elim_r P Q : (P ∧ Q)%I ⊆ Q. Proof. by intros x n ? [??]. Qed. Lemma iprop_and_intro R P Q : R ⊆ P → R ⊆ Q → R ⊆ (P ∧ Q)%I. Proof. intros HP HQ x n ??; split. by apply HP. by apply HQ. Qed. Lemma iprop_or_intro_l P Q : P ⊆ (P ∨ Q)%I. Proof. by left. Qed. Lemma iprop_or_intro_r P Q : Q ⊆ (P ∨ Q)%I. Proof. by right. Qed. Lemma iprop_or_elim R P Q : P ⊆ R → Q ⊆ R → (P ∨ Q)%I ⊆ R. Proof. intros HP HQ x n ? [?|?]. by apply HP. by apply HQ. Qed. Lemma iprop_impl_intro P Q R : (R ∧ P)%I ⊆ Q → R ⊆ (P → Q)%I. Proof. intros HQ x n ?? x' n' ????; apply HQ; naive_solver eauto using iprop_weaken. Qed. Lemma iprop_impl_elim P Q : ((P → Q) ∧ P)%I ⊆ Q. Proof. by intros x n ? [HQ HP]; apply HQ. Qed. Lemma iprop_forall_intro P `(Q: B → iProp A): (∀ b, P ⊆ Q b) → P ⊆ (∀ b, Q b)%I. Proof. by intros HPQ x n ?? b; apply HPQ. Qed. Lemma iprop_forall_elim `(P : B → iProp A) b : (∀ b, P b)%I ⊆ P b. Proof. intros x n ? HP; apply HP. Qed. Lemma iprop_exist_intro `(P : B → iProp A) b : P b ⊆ (∃ b, P b)%I. Proof. by intros x n ??; exists b. Qed. Lemma iprop_exist_elim `(P : B → iProp A) Q : (∀ b, P b ⊆ Q) → (∃ b, P b)%I ⊆ Q. Proof. by intros HPQ x n ? [b ?]; apply HPQ with b. Qed. (* BI connectives *) Lemma iprop_sep_elim_l P Q : (P ★ Q)%I ⊆ P. Proof. intros x n Hvalid (x1&x2&Hx&?&?); rewrite Hx in Hvalid |- *. by apply iprop_weaken with x1 n; auto using ra_included_l. Qed. Global Instance iprop_sep_left_id : LeftId (≡) True%I (@iprop_sep A). Proof. intros P x n Hvalid; split. * intros (x1&x2&Hx&_&?); rewrite Hx in Hvalid |- *. apply iprop_weaken with x2 n; auto using ra_included_r. `````` Robbert Krebbers committed Nov 11, 2015 265 `````` * by intros ?; exists (unit x), x; rewrite ra_unit_l. `````` Robbert Krebbers committed Nov 11, 2015 266 267 268 269 ``````Qed. Global Instance iprop_sep_commutative : Commutative (≡) (@iprop_sep A). Proof. by intros P Q x n ?; split; `````` Robbert Krebbers committed Nov 11, 2015 270 `````` intros (x1&x2&?&?&?); exists x2, x1; rewrite (commutative op). `````` Robbert Krebbers committed Nov 11, 2015 271 272 273 274 ``````Qed. Global Instance iprop_sep_associative : Associative (≡) (@iprop_sep A). Proof. intros P Q R x n ?; split. `````` Robbert Krebbers committed Nov 11, 2015 275 `````` * intros (x1&x2&Hx&?&y1&y2&Hy&?&?); exists (x1 ⋅ y1), y2; split_ands; auto. `````` Robbert Krebbers committed Nov 11, 2015 276 `````` + by rewrite <-(associative op), <-Hy, <-Hx. `````` Robbert Krebbers committed Nov 11, 2015 277 278 `````` + by exists x1, y1. * intros (x1&x2&Hx&(y1&y2&Hy&?&?)&?); exists y1, (y2 ⋅ x2); split_ands; auto. `````` Robbert Krebbers committed Nov 11, 2015 279 `````` + by rewrite (associative op), <-Hy, <-Hx. `````` Robbert Krebbers committed Nov 11, 2015 280 `````` + by exists y2, x2. `````` Robbert Krebbers committed Nov 11, 2015 281 282 283 284 ``````Qed. Lemma iprop_wand_intro P Q R : (R ★ P)%I ⊆ Q → R ⊆ (P -★ Q)%I. Proof. intros HPQ x n ?? x' n' ???; apply HPQ; auto. `````` Robbert Krebbers committed Nov 11, 2015 285 `````` exists x, x'; split_ands; auto. `````` Robbert Krebbers committed Nov 11, 2015 286 287 288 289 290 291 292 293 `````` eapply iprop_weaken with x n; eauto using cmra_valid_op_l. Qed. Lemma iprop_wand_elim P Q : ((P -★ Q) ★ P)%I ⊆ Q. Proof. by intros x n Hvalid (x1&x2&Hx&HPQ&?); rewrite Hx in Hvalid |- *; apply HPQ. Qed. Lemma iprop_sep_or P Q R : ((P ∨ Q) ★ R)%I ≡ ((P ★ R) ∨ (Q ★ R))%I. Proof. `````` Robbert Krebbers committed Nov 11, 2015 294 295 `````` split; [by intros (x1&x2&Hx&[?|?]&?); [left|right]; exists x1, x2|]. intros [(x1&x2&Hx&?&?)|(x1&x2&Hx&?&?)]; exists x1, x2; split_ands; `````` Robbert Krebbers committed Nov 11, 2015 296 297 298 `````` first [by left | by right | done]. Qed. Lemma iprop_sep_and P Q R : ((P ∧ Q) ★ R)%I ⊆ ((P ★ R) ∧ (Q ★ R))%I. `````` Robbert Krebbers committed Nov 11, 2015 299 ``````Proof. by intros x n ? (x1&x2&Hx&[??]&?); split; exists x1, x2. Qed. `````` Robbert Krebbers committed Nov 11, 2015 300 301 302 ``````Lemma iprop_sep_exist {B} (P : B → iProp A) Q : ((∃ b, P b) ★ Q)%I ≡ (∃ b, P b ★ Q)%I. Proof. `````` Robbert Krebbers committed Nov 11, 2015 303 304 `````` split; [by intros (x1&x2&Hx&[b ?]&?); exists b, x1, x2|]. intros [b (x1&x2&Hx&?&?)]; exists x1, x2; split_ands; by try exists b. `````` Robbert Krebbers committed Nov 11, 2015 305 306 307 ``````Qed. Lemma iprop_sep_forall `(P : B → iProp A) Q : ((∀ b, P b) ★ Q)%I ⊆ (∀ b, P b ★ Q)%I. `````` Robbert Krebbers committed Nov 11, 2015 308 ``````Proof. by intros x n ? (x1&x2&Hx&?&?); intros b; exists x1, x2. Qed. `````` Robbert Krebbers committed Nov 11, 2015 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 `````` (* Later *) Global Instance iprop_later_contractive : Contractive (@iprop_later A). Proof. intros n P Q HPQ x [|n'] ??; simpl; [done|]. apply HPQ; eauto using cmra_valid_S. Qed. Lemma iprop_later_weaken P : P ⊆ (▷ P)%I. Proof. intros x [|n] ??; simpl in *; [done|]. apply iprop_weaken with x (S n); auto using cmra_valid_S. Qed. Lemma iprop_lub P : (▷ P → P)%I ⊆ P. Proof. intros x n ? HP; induction n as [|n IH]; [by apply HP|]. apply HP, IH, iprop_weaken with x (S n); eauto using cmra_valid_S. Qed. Lemma iprop_later_impl P Q : (▷ (P → Q))%I ⊆ (▷ P → ▷ Q)%I. Proof. intros x [|n] ? HPQ x' [|n'] ???; auto with lia. apply HPQ; auto using cmra_valid_S. Qed. Lemma iprop_later_and P Q : (▷ (P ∧ Q))%I ≡ (▷ P ∧ ▷ Q)%I. Proof. by intros x [|n]; split. Qed. Lemma iprop_later_or P Q : (▷ (P ∨ Q))%I ≡ (▷ P ∨ ▷ Q)%I. Proof. intros x [|n]; simpl; tauto. Qed. Lemma iprop_later_forall `(P : B → iProp A) : (▷ ∀ b, P b)%I ≡ (∀ b, ▷ P b)%I. Proof. by intros x [|n]. Qed. Lemma iprop_later_exist `(P : B → iProp A) : (∃ b, ▷ P b)%I ⊆ (▷ ∃ b, P b)%I. Proof. by intros x [|n]. Qed. Lemma iprop_later_exist' `{Inhabited B} (P : B → iProp A) : (▷ ∃ b, P b)%I ≡ (∃ b, ▷ P b)%I. Proof. intros x [|n]; split; try done. by destruct (_ : Inhabited B) as [b]; exists b. Qed. Lemma iprop_later_sep P Q : (▷ (P ★ Q))%I ≡ (▷ P ★ ▷ Q)%I. Proof. intros x n ?; split. `````` Robbert Krebbers committed Nov 11, 2015 348 `````` * destruct n as [|n]; simpl; [by exists x, x|intros (x1&x2&Hx&?&?)]. `````` Robbert Krebbers committed Nov 11, 2015 349 350 `````` destruct (cmra_extend_op x x1 x2 n) as ([y1 y2]&Hx'&Hy1&Hy2); auto using cmra_valid_S; simpl in *. `````` Robbert Krebbers committed Nov 11, 2015 351 `````` exists y1, y2; split; [by rewrite Hx'|by rewrite Hy1, Hy2]. `````` Robbert Krebbers committed Nov 11, 2015 352 `````` * destruct n as [|n]; simpl; [done|intros (x1&x2&Hx&?&?)]. `````` Robbert Krebbers committed Nov 11, 2015 353 `````` exists x1, x2; eauto using (dist_S (A:=A)). `````` Robbert Krebbers committed Nov 11, 2015 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 ``````Qed. (* Always *) Lemma iprop_always_necessity P : (□ P)%I ⊆ P. Proof. intros x n ??; apply iprop_weaken with (unit x) n;auto using ra_included_unit. Qed. Lemma iprop_always_intro P Q : (□ P)%I ⊆ Q → (□ P)%I ⊆ (□ Q)%I. Proof. intros HPQ x n ??; apply HPQ; simpl in *; auto using cmra_unit_valid. by rewrite ra_unit_idempotent. Qed. Lemma iprop_always_impl P Q : (□ (P → Q))%I ⊆ (□P → □Q)%I. Proof. intros x n ? HPQ x' n' ???. apply HPQ; auto using ra_unit_preserving, cmra_unit_valid. Qed. Lemma iprop_always_and P Q : (□ (P ∧ Q))%I ≡ (□ P ∧ □ Q)%I. Proof. done. Qed. Lemma iprop_always_or P Q : (□ (P ∨ Q))%I ≡ (□ P ∨ □ Q)%I. Proof. done. Qed. Lemma iprop_always_forall `(P : B → iProp A) : (□ ∀ b, P b)%I ≡ (∀ b, □ P b)%I. Proof. done. Qed. Lemma iprop_always_exist `(P : B → iProp A) : (□ ∃ b, P b)%I ≡ (∃ b, □ P b)%I. Proof. done. Qed. Lemma iprop_always_and_always_box P Q : (□ P ∧ Q)%I ⊆ (□ P ★ Q)%I. Proof. `````` Robbert Krebbers committed Nov 11, 2015 381 `````` intros x n ? [??]; exists (unit x), x; simpl in *. `````` Robbert Krebbers committed Nov 11, 2015 382 383 384 385 386 387 388 389 390 `````` by rewrite ra_unit_l, ra_unit_idempotent. Qed. (* Fix *) Lemma iprop_fixpoint_unfold (P : iProp A → iProp A) `{!Contractive P} : iprop_fixpoint P ≡ P (iprop_fixpoint P). Proof. apply fixpoint_unfold. Qed. End logic. ``````