update to more automatic solution syntax

README.md

@@ -69,12 +69,13 @@ macOS).
 
 The syntax for the solution files is as follows:
 ```
-(* BEGIN SOLUTION *)
+(* SOLUTION *) Proof.
   solution here.
-(* END SOLUTION *)
+Qed.
 ```
 is replaced by
 ```
+Proof.
   (* exercise *)
 Admitted.
 ```

exercises/ex_03_spinlock.v

@@ -102,7 +102,8 @@ Section proof.
     - wp_cmpxchg_fail. iMod ("Hclose" with "[Hl]") as "_".
       { iNext. iExists true. iFrame. }
       iModIntro. wp_proj.
-    (* exercise *)
+      (* exercise *) admit.
+    - (* exercise *) admit.
   Admitted.
 
   (** *Exercise*: prove the spec of [acquire]. Since [acquire] is a recursive

gen-exercises.awk

 BEGIN {
-    in_solution = 0;
+    in_solution = 0; # for the advanced solution syntax
+    in_auto_solution = 0; # for the simple solution syntax that recognizes `Qed.`
 }
 { # on every line of the input
-    if (match($0, /^( *)\(\* *BEGIN SOLUTION *\*\)$/, groups)) {
-        in_solution = 1
-    } else if (match($0, /^( *)\(\* *END SOLUTION *\*\)$/, groups)) {
+    if (match($0, /^( *)\(\* *SOLUTION *\*\) *Proof.$/, groups)) {
+        print groups[1] "Proof."
+        in_auto_solution = 1
+    } else if (in_auto_solution == 1 && match($0, /^( *)Qed.$/, groups)) {
         print groups[1] "  (* exercise *)"
         print groups[1] "Admitted."
-        in_solution = 0
+        in_auto_solution = 0
+    } else if (match($0, /^( *)\(\* *BEGIN SOLUTION *\*\)$/, groups)) {
+        in_solution = 1
     } else if (match($0, /^( *)\(\* *END SOLUTION BEGIN TEMPLATE *$/, groups)) {
         in_solution = 0
     } else if (match($0, /^( *)END TEMPLATE *\*\)$/, groups)) {
         # Nothing to do, just do not print this line.
-    } else if (in_solution == 0) {
+    } else if (in_solution == 0 && in_auto_solution == 0) {
         gsub("From solutions Require", "From exercises Require")
         print
     }

solutions/ex_01_swap.v

@@ -136,12 +136,10 @@ Lemma rotate_l_spec x y z v1 v2 v3 :
   {{{ x ↦ v1 ∗ y ↦ v2 ∗ z ↦ v3 }}}
     rotate_l #x #y #z
   {{{ RET #(); x ↦ v2 ∗ y ↦ v3 ∗ z ↦ v1 }}}.
-Proof.
-(* BEGIN SOLUTION *)
+(* SOLUTION *) Proof.
   iIntros (Φ) "(Hx & Hy & Hz) Post". unfold rotate_l. wp_lam. do 2 wp_let.
   wp_apply (swap_spec with "[$Hx $Hy]"); iIntros "[Hx Hy]"; wp_seq.
   wp_apply (swap_spec with "[$Hy $Hz]"); iIntros "[Hy Hz]".
   iApply ("Post" with "[$]").
 Qed.
-(* END SOLUTION *)
 End proof.

solutions/ex_02_sumlist.v

@@ -116,8 +116,7 @@ Lemma inc_list_spec_induction n l v :
   {{{ is_list l v }}}
     inc_list #n v
   {{{ RET #(); is_list (map (Z.add n) l) v }}}.
-Proof.
-(* BEGIN SOLUTION *)
+(* SOLUTION *) Proof.
   iIntros (Φ) "Hl Post".
   iInduction l as [|x l] "IH" forall (v Φ); simpl.
   - iDestruct "Hl" as %->.
@@ -134,15 +133,13 @@ Proof.
     iExists p. iSplitR; [done|].
     iExists v. iSplitR "Hl"; [iApply "Hp"|iApply "Hl"].
 Qed.
-(* END SOLUTION *)
 
 (** *Exercise*: Now do the proof again using Löb induction. *)
 Lemma inc_list_spec_löb n l v :
   {{{ is_list l v }}}
     inc_list #n v
   {{{ RET #(); is_list (map (Z.add n) l) v }}}.
-Proof.
-(* BEGIN SOLUTION *)
+(* SOLUTION *) Proof.
   iIntros (Φ) "Hl Post".
   iLöb as "IH" forall (l v Φ). destruct l as [|x l]; simpl; wp_rec; wp_let.
   - iDestruct "Hl" as %->. wp_match. by iApply "Post".
@@ -151,7 +148,6 @@ Proof.
     wp_apply ("IH" with "Hl"). iIntros "Hl".
     iApply "Post". eauto with iFrame.
 Qed.
-(* END SOLUTION *)
 
 (** *Exercise*: Do the proof of [sum_inc_list] by making use of the lemmas of
 [sum_list] and [inc_list] we just proved. Make use of [wp_apply]. *)
@@ -159,13 +155,11 @@ Lemma sum_inc_list_spec n l v :
   {{{ is_list l v }}}
     sum_inc_list #n v
   {{{ RET #(sum_list_coq (map (Z.add n) l)); is_list (map (Z.add n) l) v }}}.
-Proof.
-(* BEGIN SOLUTION *)
+(* SOLUTION *) Proof.
   iIntros (Φ) "Hl Post". wp_lam. wp_let.
   wp_apply (inc_list_spec_induction with "Hl"); iIntros "Hl /="; wp_seq.
   wp_apply (sum_list_spec_induction with "Hl"); auto.
 Qed.
-(* END SOLUTION *)
 
 (** *Optional exercise*: Prove the following spec of [map_list] which makes use
 of a nested Texan triple, This spec is rather weak, as it requires [f] to be
@@ -173,8 +167,7 @@ pure, if you like, you can try to make it more general. *)
 Lemma map_list_spec_induction (f : val) (f_coq : Z → Z) l v :
   (∀ n, {{{ True }}} f #n {{{ RET #(f_coq n); True }}}) -∗
   {{{ is_list l v }}} map_list f v {{{ RET #(); is_list (map f_coq l) v }}}.
-Proof.
-(* BEGIN SOLUTION *)
+(* SOLUTION *) Proof.
   iIntros "#Hf" (Φ) "!# Hl Post".
   iLöb as "IH" forall (l v Φ). destruct l as [|x l]; simpl; wp_rec; wp_let.
   - iDestruct "Hl" as %->. wp_match. by iApply "Post".
@@ -185,5 +178,4 @@ Proof.
     wp_apply ("IH" with "Hl"). iIntros "Hl".
     iApply "Post". eauto with iFrame.
 Qed.
-(* END SOLUTION *)
 End proof.

solutions/ex_03_spinlock.v

@@ -109,21 +109,23 @@ Section proof.
       { iNext. iExists true. iFrame. }
       iModIntro. wp_proj. by iApply ("HΦ" $! true with "HR").
   Qed.
-  (* END SOLUTION *)
+  (* END SOLUTION BEGIN TEMPLATE
+      (* exercise *) admit.
+    - (* exercise *) admit.
+  Admitted.
+  END TEMPLATE *)
 
   (** *Exercise*: prove the spec of [acquire]. Since [acquire] is a recursive
   function, you should use the tactic [iLöb] for Löb induction. Use the tactic
   [wp_apply] to use [try_acquire_spec] when appropriate. *)
   Lemma acquire_spec lk R :
     {{{ is_lock lk R }}} acquire lk {{{ RET #(); R }}}.
-  Proof.
-  (* BEGIN SOLUTION *)
+  (* SOLUTION *) Proof.
     iIntros (Φ) "#Hl HΦ". iLöb as "IH". wp_rec.
     wp_apply (try_acquire_spec with "Hl"). iIntros ([]).
     - iIntros "HR". wp_if. by iApply "HΦ".
     - iIntros "_". wp_if. iApply ("IH" with "HΦ").
   Qed.
-  (* END SOLUTION *)
 
   (** *Exercise*: prove the spec of [release]. At a certain point in this proof,
   you need to open the invariant. For this you can use:
@@ -134,12 +136,10 @@ Section proof.
   invariant. *)
   Lemma release_spec lk R :
     {{{ is_lock lk R ∗ R }}} release lk {{{ RET #(); True }}}.
-  Proof.
-  (* BEGIN SOLUTION *)
+  (* SOLUTION *) Proof.
     iIntros (Φ) "(Hlock & HR) HΦ".
     iDestruct "Hlock" as (l ->) "#Hinv /=".
     wp_lam. iInv lockN as (b) "[Hl _]" "Hclose".
     wp_store. iApply "HΦ". iApply "Hclose". iNext. iExists false. iFrame.
   Qed.
-  (* END SOLUTION *)
 End proof.

solutions/ex_05_parallel_add_mul.v

@@ -73,8 +73,7 @@ Section proof.
 
   Lemma parallel_add_mul_spec :
     {{{ True }}} parallel_add_mul {{{ z, RET #z; ⌜ z = 2%Z ∨ z = 4%Z ⌝ }}}.
-  Proof.
-  (* BEGIN SOLUTION *)
+  (* SOLUTION *) Proof.
     iIntros (Φ) "_ Post".
     unfold parallel_add_mul. wp_alloc r as "Hr". wp_let.
     iMod (ghost_var_alloc false) as (γ1) "[Hγ1● Hγ1◯]".
@@ -107,5 +106,4 @@ Section proof.
       iDestruct (ghost_var_agree with "Hγ2● Hγ2◯") as %->.
       auto.
   Qed.
-  (* END SOLUTION *)
 End proof.