Change WP so that we have an fupd before the later, but after the quantification over next states.

theories/program_logic/adequacy.v

@@ -77,8 +77,8 @@ Proof.
   rewrite {1}wp_unfold /wp_pre. iIntros (?) "[(Hw & HE & Hσ) H]".
   rewrite (val_stuck e1 σ1 e2 σ2 efs) // uPred_fupd_eq.
   iMod ("H" $! σ1 with "Hσ [Hw HE]") as ">(Hw & HE & _ & H)"; first by iFrame.
-  iModIntro; iNext.
-  iMod ("H" $! e2 σ2 efs with "[%] [$Hw $HE]") as ">($ & $ & $ & $)"; auto.
+  iMod ("H" $! e2 σ2 efs with "[//] [$Hw $HE]") as ">(Hw & HE & H)".
+  iIntros "!> !>". by iMod ("H" with "[$Hw $HE]") as ">($ & $ & $)".
 Qed.
 
 Lemma wptp_step s e1 t1 t2 σ1 σ2 Φ :

theories/program_logic/ectx_lifting.v

@@ -14,20 +14,32 @@ Hint Resolve head_prim_reducible head_reducible_prim_step.
 Hint Resolve (reducible_not_val _ inhabitant).
 Hint Resolve head_stuck_stuck.
 
-Lemma wp_lift_head_step {s E Φ} e1 :
+Lemma wp_lift_head_step_fupd {s E Φ} e1 :
   to_val e1 = None →
   (∀ σ1, state_interp σ1 ={E,∅}=∗
     ⌜head_reducible e1 σ1⌝ ∗
-    ▷ ∀ e2 σ2 efs, ⌜head_step e1 σ1 e2 σ2 efs⌝ ={∅,E}=∗
+    ∀ e2 σ2 efs, ⌜head_step e1 σ1 e2 σ2 efs⌝ ={∅}=∗ ▷ |={∅,E}=>
       state_interp σ2 ∗ WP e2 @ s; E {{ Φ }} ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
   ⊢ WP e1 @ s; E {{ Φ }}.
 Proof.
-  iIntros (?) "H". iApply wp_lift_step=>//. iIntros (σ1) "Hσ".
+  iIntros (?) "H". iApply wp_lift_step_fupd=>//. iIntros (σ1) "Hσ".
   iMod ("H" with "Hσ") as "[% H]"; iModIntro.
-  iSplit; first by destruct s; eauto. iNext. iIntros (e2 σ2 efs) "%".
+  iSplit; first by destruct s; eauto. iIntros (e2 σ2 efs) "%".
   iApply "H"; eauto.
 Qed.
 
+Lemma wp_lift_head_step {s E Φ} e1 :
+  to_val e1 = None →
+  (∀ σ1, state_interp σ1 ={E,∅}=∗
+    ⌜head_reducible e1 σ1⌝ ∗
+    ▷ ∀ e2 σ2 efs, ⌜head_step e1 σ1 e2 σ2 efs⌝ ={∅,E}=∗
+      state_interp σ2 ∗ WP e2 @ s; E {{ Φ }} ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
+  ⊢ WP e1 @ s; E {{ Φ }}.
+Proof.
+  iIntros (?) "H". iApply wp_lift_head_step_fupd; [done|]. iIntros (?) "?".
+  iMod ("H" with "[$]") as "[$ H]". iIntros "!>" (e2 σ2 efs ?) "!> !>". by iApply "H".
+Qed.
+
 Lemma wp_lift_head_stuck E Φ e :
   to_val e = None →
   sub_redexes_are_values e →
@@ -45,7 +57,7 @@ Lemma wp_lift_pure_head_step {s E E' Φ} e1 :
     WP e2 @ s; E {{ Φ }} ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
   ⊢ WP e1 @ s; E {{ Φ }}.
 Proof using Hinh.
-  iIntros (??) "H". iApply wp_lift_pure_step; eauto.
+  iIntros (??) "H". iApply wp_lift_pure_step; [|by eauto|].
   { by destruct s; auto. }
   iApply (step_fupd_wand with "H"); iIntros "H".
   iIntros (????). iApply "H"; eauto.
@@ -62,6 +74,21 @@ Proof using Hinh.
   by auto.
 Qed.
 
+Lemma wp_lift_atomic_head_step_fupd {s E1 E2 Φ} e1 :
+  to_val e1 = None →
+  (∀ σ1, state_interp σ1 ={E1}=∗
+    ⌜head_reducible e1 σ1⌝ ∗
+    ∀ e2 σ2 efs, ⌜head_step e1 σ1 e2 σ2 efs⌝ ={E1,E2}▷=∗
+      state_interp σ2 ∗
+      from_option Φ False (to_val e2) ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
+  ⊢ WP e1 @ s; E1 {{ Φ }}.
+Proof.
+  iIntros (?) "H". iApply wp_lift_atomic_step_fupd; [done|].
+  iIntros (σ1) "Hσ1". iMod ("H" with "Hσ1") as "[% H]"; iModIntro.
+  iSplit; first by destruct s; auto. iIntros (e2 σ2 efs) "%".
+  iApply "H"; auto.
+Qed.
+
 Lemma wp_lift_atomic_head_step {s E Φ} e1 :
   to_val e1 = None →
   (∀ σ1, state_interp σ1 ={E}=∗
@@ -77,6 +104,20 @@ Proof.
   iApply "H"; auto.
 Qed.
 
+Lemma wp_lift_atomic_head_step_no_fork_fupd {s E1 E2 Φ} e1 :
+  to_val e1 = None →
+  (∀ σ1, state_interp σ1 ={E1}=∗
+    ⌜head_reducible e1 σ1⌝ ∗
+    ∀ e2 σ2 efs, ⌜head_step e1 σ1 e2 σ2 efs⌝ ={E1,E2}▷=∗
+      ⌜efs = []⌝ ∗ state_interp σ2 ∗ from_option Φ False (to_val e2))
+  ⊢ WP e1 @ s; E1 {{ Φ }}.
+Proof.
+  iIntros (?) "H". iApply wp_lift_atomic_head_step_fupd; [done|].
+  iIntros (σ1) "Hσ1". iMod ("H" $! σ1 with "Hσ1") as "[$ H]"; iModIntro.
+  iIntros (v2 σ2 efs) "%". iMod ("H" $! v2 σ2 efs with "[# //]") as "H".
+  iIntros "!> !>". iMod "H" as "(% & $ & $)"; subst; auto.
+Qed.
+
 Lemma wp_lift_atomic_head_step_no_fork {s E Φ} e1 :
   to_val e1 = None →
   (∀ σ1, state_interp σ1 ={E}=∗

theories/program_logic/lifting.v

@@ -11,16 +11,16 @@ Implicit Types σ : state Λ.
 Implicit Types P Q : iProp Σ.
 Implicit Types Φ : val Λ → iProp Σ.
 
-Lemma wp_lift_step s E Φ e1 :
+Lemma wp_lift_step_fupd s E Φ e1 :
   to_val e1 = None →
   (∀ σ1, state_interp σ1 ={E,∅}=∗
     ⌜if s is NotStuck then reducible e1 σ1 else True⌝ ∗
-    ▷ ∀ e2 σ2 efs, ⌜prim_step e1 σ1 e2 σ2 efs⌝ ={∅,E}=∗
+    ∀ e2 σ2 efs, ⌜prim_step e1 σ1 e2 σ2 efs⌝ ={∅}=∗ ▷ |={∅,E}=>
       state_interp σ2 ∗ WP e2 @ s; E {{ Φ }} ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
   ⊢ WP e1 @ s; E {{ Φ }}.
 Proof.
   rewrite wp_unfold /wp_pre=>->. iIntros "H" (σ1) "Hσ".
-  iMod ("H" with "Hσ") as "(%&?)". iModIntro. iSplit. by destruct s. done.
+  iMod ("H" with "Hσ") as "(%&H)". iModIntro. iSplit. by destruct s. done.
 Qed.
 
 Lemma wp_lift_stuck E Φ e :
@@ -30,10 +30,22 @@ Lemma wp_lift_stuck E Φ e :
 Proof.
   rewrite wp_unfold /wp_pre=>->. iIntros "H" (σ1) "Hσ".
   iMod ("H" with "Hσ") as %[? Hirr]. iModIntro. iSplit; first done.
-  iIntros "!>" (e2 σ2 efs) "%". by case: (Hirr e2 σ2 efs).
+  iIntros (e2 σ2 efs) "% !> !>". by case: (Hirr e2 σ2 efs).
 Qed.
 
 (** Derived lifting lemmas. *)
+Lemma wp_lift_step s E Φ e1 :
+  to_val e1 = None →
+  (∀ σ1, state_interp σ1 ={E,∅}=∗
+    ⌜if s is NotStuck then reducible e1 σ1 else True⌝ ∗
+    ▷ ∀ e2 σ2 efs, ⌜prim_step e1 σ1 e2 σ2 efs⌝ ={∅,E}=∗
+      state_interp σ2 ∗ WP e2 @ s; E {{ Φ }} ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
+  ⊢ WP e1 @ s; E {{ Φ }}.
+Proof.
+  iIntros (?) "H". iApply wp_lift_step_fupd; [done|]. iIntros (?) "Hσ".
+  iMod ("H" with "Hσ") as "[$ H]". iIntros "!> * % !>". by iApply "H".
+Qed.
+
 Lemma wp_lift_pure_step `{Inhabited (state Λ)} s E E' Φ e1 :
   (∀ σ1, if s is NotStuck then reducible e1 σ1 else to_val e1 = None) →
   (∀ σ1 e2 σ2 efs, prim_step e1 σ1 e2 σ2 efs → σ1 = σ2) →
@@ -65,6 +77,26 @@ Qed.
 
 (* Atomic steps don't need any mask-changing business here, one can
    use the generic lemmas here. *)
+Lemma wp_lift_atomic_step_fupd {s E1 E2 Φ} e1 :
+  to_val e1 = None →
+  (∀ σ1, state_interp σ1 ={E1}=∗
+    ⌜if s is NotStuck then reducible e1 σ1 else True⌝ ∗
+    ∀ e2 σ2 efs, ⌜prim_step e1 σ1 e2 σ2 efs⌝ ={E1,E2}▷=∗
+      state_interp σ2 ∗
+      from_option Φ False (to_val e2) ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
+  ⊢ WP e1 @ s; E1 {{ Φ }}.
+Proof.
+  iIntros (?) "H". iApply (wp_lift_step_fupd s E1 _ e1)=>//; iIntros (σ1) "Hσ1".
+  iMod ("H" $! σ1 with "Hσ1") as "[$ H]".
+  iMod (fupd_intro_mask' E1 ∅) as "Hclose"; first set_solver.
+  iIntros "!>" (e2 σ2 efs ?). iMod "Hclose" as "_".
+  iMod ("H" $! e2 σ2 efs with "[#]") as "H"; [done|].
+  iMod (fupd_intro_mask' E2 ∅) as "Hclose"; [set_solver|]. iIntros "!> !>".
+  iMod "Hclose" as "_". iMod "H" as "($ & HΦ & $)".
+  destruct (to_val e2) eqn:?; last by iExFalso.
+  by iApply wp_value.
+Qed.
+
 Lemma wp_lift_atomic_step {s E Φ} e1 :
   to_val e1 = None →
   (∀ σ1, state_interp σ1 ={E}=∗
@@ -74,13 +106,9 @@ Lemma wp_lift_atomic_step {s E Φ} e1 :
       from_option Φ False (to_val e2) ∗ [∗ list] ef ∈ efs, WP ef @ s; ⊤ {{ _, True }})
   ⊢ WP e1 @ s; E {{ Φ }}.
 Proof.
-  iIntros (?) "H". iApply (wp_lift_step s E _ e1)=>//; iIntros (σ1) "Hσ1".
-  iMod ("H" $! σ1 with "Hσ1") as "[$ H]".
-  iMod (fupd_intro_mask' E ∅) as "Hclose"; first set_solver.
-  iModIntro; iNext; iIntros (e2 σ2 efs) "%". iMod "Hclose" as "_".
-  iMod ("H" $! e2 σ2 efs with "[#]") as "($ & HΦ & $)"; first by eauto.
-  destruct (to_val e2) eqn:?; last by iExFalso.
-  by iApply wp_value.
+  iIntros (?) "H". iApply wp_lift_atomic_step_fupd; [done|].
+  iIntros (?) "?". iMod ("H" with "[$]") as "[$ H]". iIntros "!> * % !> !>".
+  by iApply "H".
 Qed.
 
 Lemma wp_lift_pure_det_step `{Inhabited (state Λ)} {s E E' Φ} e1 e2 efs :

theories/program_logic/total_weakestpre.v

@@ -315,9 +315,9 @@ Lemma twp_wp s E e Φ : WP e @ s; E [{ Φ }] -∗ WP e @ s; E {{ Φ }}.
 Proof.
   iIntros "H". iLöb as "IH" forall (E e Φ).
   rewrite wp_unfold twp_unfold /wp_pre /twp_pre. destruct (to_val e) as [v|]=>//.
-  iIntros (σ1) "Hσ". iMod ("H" with "Hσ") as "[$ H]". iModIntro; iNext.
-  iIntros (e2 σ2 efs) "Hstep".
-  iMod ("H" with "Hstep") as "($ & H & Hfork)"; iModIntro.
+  iIntros (σ1) "Hσ". iMod ("H" with "Hσ") as "[$ H]". iIntros "!>".
+  iIntros (e2 σ2 efs) "Hstep". iMod ("H" with "Hstep") as "($ & H & Hfork)".
+  iApply step_fupd_intro; [set_solver+|]. iNext.
   iSplitL "H". by iApply "IH". iApply (@big_sepL_impl with "[$Hfork]").
   iIntros "!#" (k e' _) "H". by iApply "IH".
 Qed.

theories/program_logic/weakestpre.v

@@ -32,7 +32,7 @@ Definition wp_pre `{irisG Λ Σ} (s : stuckness)
   | Some v => |={E}=> Φ v
   | None => ∀ σ1,
      state_interp σ1 ={E,∅}=∗ ⌜if s is NotStuck then reducible e1 σ1 else True⌝ ∗
-     ▷ ∀ e2 σ2 efs, ⌜prim_step e1 σ1 e2 σ2 efs⌝ ={∅,E}=∗
+     ∀ e2 σ2 efs, ⌜prim_step e1 σ1 e2 σ2 efs⌝ ={∅}=∗ ▷ |={∅,E}=>
        state_interp σ2 ∗ wp E e2 Φ ∗
        [∗ list] ef ∈ efs, wp ⊤ ef (λ _, True)
   end%I.
@@ -197,7 +197,7 @@ Proof.
   (* FIXME: figure out a way to properly automate this proof *)
   (* FIXME: reflexivity, as being called many times by f_equiv and f_contractive
   is very slow here *)
-  do 17 (f_contractive || f_equiv). apply IH; first lia.
+  do 18 (f_contractive || f_equiv). apply IH; first lia.
   intros v. eapply dist_le; eauto with omega.
 Qed.
 Global Instance wp_proper s E e :
@@ -221,8 +221,8 @@ Proof.
   { iApply ("HΦ" with "[> -]"). by iApply (fupd_mask_mono E1 _). }
   iIntros (σ1) "Hσ". iMod (fupd_intro_mask' E2 E1) as "Hclose"; first done.
   iMod ("H" with "[$]") as "[% H]".
-  iModIntro. iSplit; [by destruct s1, s2|]. iNext. iIntros (e2 σ2 efs Hstep).
-  iMod ("H" with "[//]") as "($ & H & Hefs)".
+  iModIntro. iSplit; [by destruct s1, s2|]. iIntros (e2 σ2 efs Hstep).
+  iMod ("H" with "[//]") as "H". iIntros "!> !>". iMod "H" as "($ & H & Hefs)".
   iMod "Hclose" as "_". iModIntro. iSplitR "Hefs".
   - iApply ("IH" with "[//] H HΦ").
   - iApply (big_sepL_impl with "[$Hefs]"); iIntros "!#" (k ef _) "H".
@@ -245,8 +245,8 @@ Proof.
   destruct (to_val e) as [v|] eqn:He.
   { by iDestruct "H" as ">>> $". }
   iIntros (σ1) "Hσ". iMod "H". iMod ("H" $! σ1 with "Hσ") as "[$ H]".
-  iModIntro. iNext. iIntros (e2 σ2 efs Hstep).
-  iMod ("H" with "[//]") as "(Hphy & H & $)". destruct s.
+  iModIntro. iIntros (e2 σ2 efs Hstep).
+  iMod ("H" with "[//]") as "H". iIntros "!>!>". iMod "H" as "(Hphy & H & $)". destruct s.
   - rewrite !wp_unfold /wp_pre. destruct (to_val e2) as [v2|] eqn:He2.
     + iDestruct "H" as ">> $". by iFrame.
     + iMod ("H" with "[$]") as "[H _]". iDestruct "H" as %(? & ? & ? & ?).
@@ -261,8 +261,8 @@ Lemma wp_step_fupd s E1 E2 e P Φ :
 Proof.
   rewrite !wp_unfold /wp_pre. iIntros (-> ?) "HR H".
   iIntros (σ1) "Hσ". iMod "HR". iMod ("H" with "[$]") as "[$ H]".
-  iModIntro; iNext; iIntros (e2 σ2 efs Hstep).
-  iMod ("H" $! e2 σ2 efs with "[% //]") as "($ & H & $)".
+  iIntros "!>" (e2 σ2 efs Hstep). iMod ("H" $! e2 σ2 efs with "[% //]") as "H".
+  iIntros "!>!>". iMod "H" as "($ & H & $)".
   iMod "HR". iModIntro. iApply (wp_strong_mono s s E2 with "H"); [done..|].
   iIntros (v) "H". by iApply "H".
 Qed.
@@ -277,10 +277,10 @@ Proof.
   iIntros (σ1) "Hσ". iMod ("H" with "[$]") as "[% H]". iModIntro; iSplit.
   { iPureIntro. destruct s; last done.
     unfold reducible in *. naive_solver eauto using fill_step. }
-  iNext; iIntros (e2 σ2 efs Hstep).
+  iIntros (e2 σ2 efs Hstep).
   destruct (fill_step_inv e σ1 e2 σ2 efs) as (e2'&->&?); auto.
-  iMod ("H" $! e2' σ2 efs with "[//]") as "($ & H & $)".
-  by iApply "IH".
+  iMod ("H" $! e2' σ2 efs with "[//]") as "H". iIntros "!>!>".
+  iMod "H" as "($ & H & $)". by iApply "IH".
 Qed.
 
 Lemma wp_bind_inv K `{!LanguageCtx K} s E e Φ :
@@ -292,9 +292,9 @@ Proof.
   rewrite fill_not_val //.
   iIntros (σ1) "Hσ". iMod ("H" with "[$]") as "[% H]". iModIntro; iSplit.
   { destruct s; eauto using reducible_fill. }
-  iNext; iIntros (e2 σ2 efs Hstep).
-  iMod ("H" $! (K e2) σ2 efs with "[]") as "($ & H & $)"; eauto using fill_step.
-  by iApply "IH".
+  iIntros (e2 σ2 efs Hstep).
+  iMod ("H" $! (K e2) σ2 efs with "[]") as "H"; [by eauto using fill_step|].
+  iIntros "!>!>". iMod "H" as "($ & H & $)". by iApply "IH".
 Qed.
 
 (** * Derived rules *)