Allow introduction patterns for result of `iCombine`.

This fixes issue #187.

ProofMode.md

@@ -108,8 +108,8 @@ Separating logic specific tactics
 
   This tactic finishes the goal in case everything in the conclusion has been
   framed.
-- `iCombine "H1" "H2" as "H"` : turns `H1 : P1` and `H2 : P2` into
-  `H : P1 ∗ P2`.
+- `iCombine "H1" "H2" as "pat"` : turns `H1 : P1` and `H2 : P2` into
+  `P1 ∗ P2`, on which `iDetruct ... as pat` is called.
 
 Modalities
 ----------

theories/proofmode/class_instances_bi.v

@@ -395,9 +395,14 @@ Proof. by rewrite /IntoWand /= intuitionistically_persistently_elim. Qed.
 Global Instance into_wand_persistently_false q R P Q :
   Absorbing R → IntoWand false q R P Q → IntoWand false q (<pers> R) P Q.
 Proof. intros ?. 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. by rewrite /IntoWand !embed_intuitionistically_if_2 -embed_wand=> ->. Qed.
+Global Instance into_wand_embed `{BiEmbed PROP PROP'} p q (PP QQ RR : PROP) (P : PROP') :
+  IntoEmbed P PP →
+  IntoWand p q RR PP QQ → IntoWand p q ⎡RR⎤ P ⎡QQ⎤.
+Proof.
+  rewrite /IntoEmbed /IntoWand !embed_intuitionistically_if_2=> -> ->.
+  apply bi.wand_intro_l.
+  by rewrite embed_intuitionistically_if_2 -embed_sep bi.wand_elim_r.
+Qed.
 
 (* FromWand *)
 Global Instance from_wand_wand P1 P2 : FromWand (P1 -∗ P2) P1 P2.
@@ -880,4 +885,7 @@ Qed.
 Global Instance into_embed_embed {PROP' : bi} `{BiEmbed PROP PROP'} P :
   IntoEmbed ⎡P⎤ P.
 Proof. by rewrite /IntoEmbed. Qed.
+Global Instance into_embed_affinely `{BiEmbedBUpd PROP PROP'} (P : PROP') (Q : PROP) :
+  IntoEmbed P Q → IntoEmbed (<affine> P) (<affine> Q).
+Proof. rewrite /IntoEmbed=> ->. by rewrite embed_affinely_2. Qed.
 End bi_instances.

theories/proofmode/ltac_tactics.v

@@ -927,20 +927,6 @@ Local Tactic Notation "iAndDestructChoice" constr(H) "as" constr(d) constr(H') :
      fail "iAndDestructChoice: cannot destruct" P
     |env_reflexivity || fail "iAndDestructChoice:" H' " not fresh"|].
 
-(** * Combinining hypotheses *)
-Tactic Notation "iCombine" constr(Hs) "as" constr(H) :=
-  let Hs := words Hs in
-  let Hs := eval vm_compute in (INamed <$> Hs) in
-  eapply tac_combine with _ _ Hs _ _ H _;
-    [env_reflexivity ||
-     let Hs := iMissingHyps Hs in
-     fail "iCombine: hypotheses" Hs "not found"
-    |iSolveTC
-    |env_reflexivity || fail "iCombine:" H "not fresh"|].
-
-Tactic Notation "iCombine" constr(H1) constr(H2) "as" constr(H) :=
-  iCombine [H1;H2] as H.
-
 (** * Existential *)
 Tactic Notation "iExists" uconstr(x1) :=
   iStartProof;
@@ -1098,6 +1084,22 @@ Tactic Notation "iDestructHyp" constr(H) "as" "(" simple_intropattern(x1)
     simple_intropattern(x8) ")" constr(pat) :=
   iExistDestruct H as x1 H; iDestructHyp H as ( x2 x3 x4 x5 x6 x7 x8 ) pat.
 
+(** * Combinining hypotheses *)
+Tactic Notation "iCombine" constr(Hs) "as" constr(pat) :=
+  let Hs := words Hs in
+  let Hs := eval vm_compute in (INamed <$> Hs) in
+  let H := iFresh in
+  eapply tac_combine with _ _ Hs _ _ H _;
+    [env_reflexivity ||
+     let Hs := iMissingHyps Hs in
+     fail "iCombine: hypotheses" Hs "not found"
+    |iSolveTC
+    |env_reflexivity || fail "iCombine:" H "not fresh"
+    |iDestructHyp H as pat].
+
+Tactic Notation "iCombine" constr(H1) constr(H2) "as" constr(pat) :=
+  iCombine [H1;H2] as pat.
+
 (** * Introduction tactic *)
 Tactic Notation "iIntros" constr(pat) :=
   let rec go pats startproof :=

theories/tests/proofmode.v

@@ -197,6 +197,10 @@ Lemma test_iCombine_persistent P Q R `{!Persistent R} :
   P -∗ Q -∗ R → R ∗ Q ∗ P ∗ R ∨ False.
 Proof. iIntros "HP HQ #HR". iCombine "HR HQ HP HR" as "H". auto. Qed.
 
+Lemma test_iCombine_frame P Q R `{!Persistent R} :
+  P -∗ Q -∗ R → R ∗ Q ∗ P ∗ R.
+Proof. iIntros "HP HQ #HR". iCombine "HQ HP HR" as "$". by iFrame. Qed.
+
 Lemma test_iNext_evar P : P -∗ True.
 Proof.
   iIntros "HP". iAssert (▷ _ -∗ ▷ P)%I as "?"; last done.