You are an expert Lean4 and formal verification agent proving a Lean4 theorem. Your output **must** strictly adhere to the specified format.

### Input Information
You will receive the following components, relevant to the target theorem:
* <all_available_defs>: Definitions available from imported modules (either from the current Lean repository or from Mathlib)
* <all_available_lemmas>: Lemmas/theorems available that may assist the proof.
* <local_ctx>...</local_ctx>: The local file context (imports, namespaces, definitions, comments, etc.) from the top of the file up to—but not including—the target theorem or any previously defined local lemmas/theorems.
* <target_theorem>...</target_theorem>: The target theorem statement, ending with `:=`.

**Notes**
1. Definitions include their full bodies, but for definitions whose bodies contain proofs, the proof parts are replaced by `admit` (i.e., admit /- proof elided -/), while the rest of the definition is kept unchanged; lemmas include only their statements.
2. You may freely reference any definition or lemma contained in these tags without redefining them.
3. The tags for available definitions and lemmas (all_available_defs, all_available_lemmas) may be omitted if empty.

### Output Format & Requirements
Your output MUST contain a complete, syntactically correct Lean 4 proof for the target theorem.

**Strict Output Structure:**
<reasoning> 
...
</reasoning> 

<lean4_invented_lemmas>
-- each lemma is a full Lean 4 declaration with a complete proof
...
</lean4_invented_lemmas>

<lean4_proof>
-- Lean 4 proof body of the target theorem
...
</lean4_proof>

**Requirements:**
1. <reasoning> and <lean4_invented_lemmas> are OPTIONAL. Include them only if they aid proof construction.
2. <lean4_proof> MUST contain only the proof body (tactics/terms), starting by "by", NOT the theorem declaration.
3. <lean4_invented_lemmas> (if present) MUST contain syntactically correct lemma declarations that type checks AND complete proof bodies. Defining a lemma using `axiom` is NOT allowed.
4. <reasoning> contains high-level proof planning.
5. If you create a lemma under <lean4_invented_lemmas> whose name is namespaced (e.g., X.Y.Z), you MUST always refer to it using its fully qualified name. Do NOT rely on shortened names. For example, write rw [X.Y.Z], not rw [Z] for invented lemmas.
6. All Lean 4 code MUST be syntactically correct. No `sorry`, `admit`, or non-Lean text. Comments allowed using `--` or `/- ... -/`.
7. Follow the tags and structure EXACTLY. No extra text before, between, or after the sections.
8. Do NOT wrap invented lemmas in a `mutual` block unless they have genuine mutual recursion. Declare each lemma independently.

### Examples are provided here (example input are under "User Prompt", and example assistant response are under "Agent Response"):
Example 1 ------------------- 
User Prompt:
<all_available_defs>
structure BitVec (w : Nat) where
  /-- Construct a `BitVec w` from a number less than `2^w`.
  O(1), because we use `Fin` as the internal representation of a bitvector. -/
  ofFin ::

  /-- Interpret a bitvector as a number less than `2^w`.
  O(1), because we use `Fin` as the internal representation of a bitvector. -/
  toFin : Fin (hPow 2 w)
</all_available_defs>

<all_available_lemmas>
theorem List.getElem_append_left{α : Type u_1} {l₁ l₂ : List α} {i : Nat} (hn : i < l₁.length) : (l₁ ++ l₂)[i] = l₁[i]
theorem getElem_eq_testBit_toNat (x : BitVec w) (i : Nat) (h : i < w) :
  x[i] = x.toNat.testBit i := rfl
@[simp, grind =] theorem toNat_cons (b : Bool) (x : BitVec w) :
    (cons b x).toNat = (b.toNat <<< w) ||| x.toNat
@[simp, grind =] theorem getLsbD_of_ge (x : BitVec w) (i : Nat) (ge : w ≤ i) : getLsbD x i = false
theorem testBit_toNat (x : BitVec w) : x.toNat.testBit i = x.getLsbD i
</all_available_lemmas>

<local_ctx>
import Mathlib.Computability.NFA
import Mathlib.Data.FinEnum
import Mathlib.Data.Rel
import Mathlib.Data.Vector.Basic
import Blase.AutoStructs.ForLean

open Set
open Mathlib
open SetRel

-- this is better because card is defeq to n
instance (α : Type) : Inter (Language α) := ⟨Set.inter⟩
instance (α : Type) : Union (Language α) := ⟨Set.union⟩

/--
The set of `n`-tuples of bit vectors of an arbitrary width.
-/
structure BitVecs (n : Nat) where
  w : Nat
  bvs : List.Vector (BitVec w) n

def BitVecs.cast (bvs : BitVecs n) (h : n = n') : BitVecs n' :=
  { w := bvs.w, bvs := h ▸ bvs.bvs }

abbrev BitVecs.empty : BitVecs n := ⟨0, List.Vector.replicate n .nil⟩
abbrev BitVecs.singleton {w : Nat} (bv : BitVec w) : BitVecs 1 := ⟨w, bv ::ᵥ .nil⟩
abbrev BitVecs.pair {w : Nat} (bv1 bv2 : BitVec w) : BitVecs 2 := ⟨w, bv1 ::ᵥ bv2 ::ᵥ .nil⟩

/--
The set of `n`-tuples of bit vectors of an arbitrary width, encoded as a list of
bit vectors of width `n`. The width of the encoded bit vectors is the length of
the list.
-/
abbrev BitVecs' (n : Nat) := List (BitVec n)

@[simps]
def dec (bvs' : BitVecs' n) : BitVecs n where
  w := bvs'.length
  bvs := List.Vector.ofFn fun k => BitVec.ofFn fun i => bvs'[i].getLsbD k

@[simp]
</local_ctx>

<target_theorem>
lemma dec_snoc n (bvs' : BitVecs' n) (a : BitVec n) :
  dec (bvs' ++ [a]) =
    { w := bvs'.length + 1
      bvs := List.Vector.ofFn fun k =>
        BitVec.cons (a.getLsbD k) ((dec bvs').bvs.get k) } :=
</target_theorem>

Agent Response:
<reasoning> 
The goal is to understand what `dec` does after appending one more bitvector `a` to `bvs'`. By definition, `dec` builds a width `= length` and a vector of bitvectors whose `i`-th bit at position `k` is `bvs'[i].getLsbD k`. So for `bvs' ++ [a]`, we expect the width to increase by 1 and each resulting bitvector to be `BitVec.cons` of the new bit coming from `a`.

First, I use `ext` twice: once on the record to focus on the `bvs` field, and once on the resulting bitvector. This reduces everything to a pointwise statement:
for fixed `k` and `i` with `i < bvs'.length + 1`,
the bit `(bvs' ++ [a])[i].getLsbD k` should match the bit at index `i` of `BitVec.cons (a.getLsbD k) ((dec bvs').bvs.get k)`.

At this point I need a clean description of indexing into `BitVec.cons`: if we have `x : BitVec n`, then `(cons b x)[i]` should give `b` at the new “last” index `n` and `x[i]` otherwise. That motivates an auxiliary lemma `getElem_cons` expressing exactly this behavior, proved via the `testBit`/`toNat` characterization and a case split on `i < n`, `i = n`, `i > n`.

Using `getElem_cons`, the RHS becomes an `if` on whether `i = bvs'.length`. So I split into cases:
- If `i = bvs'.length`, then `(bvs' ++ [a])[i]` is the appended `a`, so both sides reduce to `a.getLsbD k`.
- If `i ≠ bvs'.length`, the bound `i < bvs'.length + 1` forces `i < bvs'.length`. Then `(bvs' ++ [a])[i] = bvs'[i]` by `List.getElem_append_left`, and the RHS takes the “else” branch and likewise gives the bit from `bvs'[i]`. In both subcases, `simp` (plus the definition of `dec`) finishes.

So the whole proof is: `ext` to bit level, unfold `dec` with `simp_all`, rewrite with `getElem_cons`, split on the boundary index `i = length bvs'`, and in the “< length” branch use `List.getElem_append_left` and bounds to line up both sides.
</reasoning> 

<lean4_invented_lemmas>
@[grind =]
theorem getElem_cons {b : Bool} {n} {x : BitVec n} {i : Nat} (h : i < n + 1) :
    (cons b x)[i] = if h : i = n then b else x[i] := by
  simp only [BitVec.getElem_eq_testBit_toNat, BitVec.toNat_cons, Nat.testBit_or]
  rw [Nat.testBit_shiftLeft]
  rcases Nat.lt_trichotomy i n with i_lt_n | i_eq_n | n_lt_i
  · have p1 : ¬(n ≤ i) := by omega
    have p2 : i ≠ n := by omega
    simp [p1, p2]
  · simp only [i_eq_n, ge_iff_le, Nat.le_refl, decide_true, Nat.sub_self, Nat.testBit_zero,
    Bool.true_and, BitVec.testBit_toNat, BitVec.getLsbD_of_ge, Bool.or_false]
    cases b <;> trivial
  · have p1 : i ≠ n := by omega
    have p2 : i - n ≠ 0 := by omega
    simp [p1, p2, Nat.testBit_bool_toNat]
</lean4_invented_lemmas>

<lean4_proof>
by
  ext k i hi <;> simp_all
  rw [getElem_cons]
  split
  next heq => simp_all
  next h =>
    have hlt : i < List.length bvs' := by simp at hi; omega
    rw [List.getElem_append_left hlt]
    simp
</lean4_proof>

### Your task:
<all_available_defs>
class AddCommMonoidWRT (α : Type) (add' : semiOutParam $ α -> α -> α) extends AddCommMonoid α where
  addE : (· + ·) = add'

@[simp]
abbrev add : val -> val -> val
  | .val_int i, .val_int j => val.val_int (i + j)
  | _, _ => val.val_unit

@[simp]
abbrev valid : val -> Prop
  | .val_int _ => True
  | _ => False

scoped instance : PartialCommMonoid val where
  add := add
  add_assoc := by admit /- proof elided -/

scoped instance inst : PartialCommMonoidWRT val add valid where
  validE := by admit /- proof elided -/

@[simp]
abbrev add : val -> val -> val
  | .val_bool i, .val_bool j => val.val_bool (i || j)
  | _, _ => val.val_unit

@[simp]
abbrev valid : val -> Prop
  | .val_bool _ => True
  | _ => False

scoped instance : PartialCommMonoid val where
  add := add
  add_assoc := by admit /- proof elided -/

scoped instance inst : PartialCommMonoidWRT val add valid where
  validE := by admit /- proof elided -/

@[simp]
abbrev add : val -> val -> val
  | .val_real i, .val_real j => val.val_real (i + j)
  | _, _ => val.val_unit

@[simp]
abbrev valid : val -> Prop
  | .val_real _ => True
  | _ => False

scoped instance : PartialCommMonoid val where
  add := add
  add_assoc := by admit /- proof elided -/

scoped instance inst : PartialCommMonoidWRT val add valid where
  validE := by admit /- proof elided -/

class PartialCommMonoid (α : Type) extends AddCommSemigroup α where
  valid : α -> Prop
  valid_add : ∀ x, valid (x + y) -> valid x
  add_valid : ∀ x y, valid x -> valid y -> valid (x + y)

inductive prim where
  
  | val_get : prim
  | val_set : prim
  
  | val_neg : prim
  | val_opp : prim
  | val_eq : prim
  | val_add : prim
  | val_neq : prim
  | val_sub : prim
  | val_mul : prim
  | val_div : prim
  | val_mod : prim
  
  | val_le : prim
  | val_lt : prim
  | val_ge : prim
  | val_gt : prim
  | val_ptr_add : prim

inductive val : Type where
    | val_unit   : val
    | val_bool   : Bool → val
    | val_int    : Int → val
    | val_real   : ℝ → val
    | val_loc    : loc → val
    | val_prim   : prim → val
    | val_fun    : var -> trm -> val
    | val_fix    : var -> var -> trm -> val
    | val_uninit : val
    | val_error : val

inductive trm : Type where
    | trm_val   : val -> trm
    | trm_var   : var -> trm
    | trm_fun   : var -> trm -> trm
    | trm_fix   : var -> var -> trm -> trm
    | trm_app   : trm -> trm -> trm
    | trm_seq   : trm -> trm -> trm
    | trm_let   : var -> trm -> trm -> trm
    | trm_if    : trm -> trm -> trm -> trm
    | trm_for   : var -> trm -> trm -> trm -> trm
    | trm_while : trm -> trm -> trm
    | trm_ref   : var → trm → trm → trm
    | trm_alloc : var → trm → trm → trm

abbrev heap := Heap.heap val

inductive evalExact : state → trm → (val → state → Prop) -> Prop where
  | val : forall s v,
      evalExact s (trm_val v) (fun v' s' ↦ v' = v ∧ s' = s)
  | fun : forall s x t1,
      evalExact s (trm_fun x t1) (fun v' s' ↦ v' = val_fun x t1 ∧ s' = s)
  | fix : forall s f x t1,
      evalExact s (trm_fix f x t1) (fun v' s' ↦ v' = val_fix f x t1 ∧ s' = s)
  | app_arg1 : forall s1 t1 t2 Q1 Q,
      ¬ trm_is_val t1 ->
      evalExact s1 t1 Q1 ->
      (forall v1 s2, Q1 v1 s2 -> evalExact s2 (trm_app v1 t2) Q) ->
      evalExact s1 (trm_app t1 t2) Q
  | app_arg2 : forall s1 (v1 : val) t2 Q1 Q,
      ¬ trm_is_val t2 ->
      evalExact s1 t2 Q1 ->
      (forall v2 s2, Q1 v2 s2 -> evalExact s2 (trm_app v1 v2) Q) ->
      evalExact s1 (trm_app v1 t2) Q
  | app_fun : forall s1 v1 (v2 :val) x t1 Q,
      v1 = val_fun x t1 ->
      evalExact s1 (subst x v2 t1) Q ->
      evalExact s1 (trm_app v1 v2) Q
  | app_fix : forall s (v1 v2 : val) f x t1 Q,
      v1 = val_fix f x t1 ->
      evalExact s (subst x v2 (subst f v1 t1)) Q ->
      evalExact s (trm_app v1 v2) Q
  | seq : forall Q1 s t1 t2 Q,
      evalExact s t1 Q1 ->
      (forall v1 s2, Q1 v1 s2 -> evalExact s2 t2 Q) ->
      evalExact s (trm_seq t1 t2) Q
  | let : forall Q1 s x t1 t2 Q,
      evalExact s t1 Q1 ->
      (forall v1 s2, Q1 v1 s2 -> evalExact s2 (subst x v1 t2) Q) ->
      evalExact s (trm_let x t1 t2) Q
  | if : forall s (b : Bool) t1 t2 Q,
      evalExact s (if b then t1 else t2) Q ->
      evalExact s (trm_if (val_bool b) t1 t2) Q
  | unop : forall op s v1 P,
      evalunop op v1 P ->
      evalExact s (trm_app op v1) (purepost s P)
  | binop : forall op s (v1 v2 : val) P,
      evalbinop op v1 v2 P ->
      evalExact s (trm_app (trm_app op v1) v2) (purepost s P)
  | ref : forall s x t1 t2 Q Q₁,
    evalExact s t1 Q₁ →
    (∀ v1 s1, Q₁ v1 s1 → ∀ p ∉ s1,
     evalExact (s1.insert p v1) (subst x p t2) fun v s ↦ Q v (s.erase p)) →
      evalExact s (trm_ref x t1 t2) Q
  | get : forall s p,
      p ∈ s ->
      evalExact s (trm_app val_get (val_loc p))
        (fun v' s' ↦ v' = read_state p s ∧ s' = s)
  | set : forall s p v,
      v = trm_val v' ->
      p ∈ s ->
      evalExact s (trm_app (trm_app val_set (val_loc p)) v)
        (fun v'' s' ↦ v'' = val_unit ∧ s' = s.insert p v')
  | alloc_arg : forall s Q₁ Q,
    ¬ trm_is_val t1 →
    evalExact s t1 Q₁ →
    (∀ v' s', Q₁ v' s' → evalExact s' (trm_alloc x v' t2) Q) →
    evalExact s (trm_alloc x t1 t2) Q
  | alloc : forall (sa : state) (n : ℤ) Q,
    n ≥ 0 →
    (∀ (p : loc) (sb : state),
      sb = conseq (make_list n.natAbs val_uninit) p →
      p ≠ null →
      Finmap.Disjoint sa sb →
      evalExact (sb ∪ sa) (subst x p t2) fun v s ↦ Q v (s \ sb)) →
    evalExact sa (trm_alloc x n t2) Q
  
  
  
  
  
  
  | for (n₁ n₂ : Int) (Q : val -> state -> Prop) :
    evalExact s (if (n₁ < n₂) then
               (trm_seq (subst x n₁ t₁) (trm_for x (val_int (n₁ + 1)) n₂ t₁))
            else val_unit) Q ->
    evalExact s (trm_for x n₁ n₂ t₁) Q
  | while (t₁ t₂ : trm) (Q Q₁ : val -> state -> Prop) :
    evalExact s t₁ Q₁ ->
    (∀ s v, Q₁ v s -> evalExact s (trm_if v (trm_seq t₂ (trm_while t₁ t₂)) val_unit) Q) ->
    evalExact s (trm_while t₁ t₂) Q

partial def repeat'' (tac : TacticM Unit) : TacticM Unit := do
  try
    withMainContext tac
  catch _ => return ()
  repeat'' tac

Add in Init.Prelude

Inhabited in Init.Prelude

HAdd.hAdd in Init.Prelude

ident in Ssreflect.IntroPats

instance (α : Type) : HWand (α → hProp) (α → hProp) hProp where
  hWand := qwand

@[default_instance]
instance : HStar hProp hProp hProp where
  hStar := hstar

Finmap.Disjoint in Mathlib.Data.Finmap

def formula_sound (t : trm) (F : formula) : Prop :=
  forall Q, F Q ==> wp t Q

tryGoal in Ssreflect.Utils

def getPrim (t :Expr) : Expr :=
  let_expr val_prim v := t | t
  v

Bool in Init.Prelude

abbrev state := Finmap (λ _ : loc ↦ val)

instance : Inhabited trm where
  default := trm.trm_val (val.val_unit)

scase_if in Ssreflect.Elim

def wp (t : trm) (Q : val → hProp) : hProp :=
  fun s ↦ eval s t Q

def val_array_get : val := [lang|
  fun p i =>
    let p1 := p ++ 1 in
    let q := p1 ++ i in
    !q ]

abbrev himpl (H1 H2 : hProp) : Prop :=
  forall h, H1 h -> H2 h

instOfNat in Init.Data.Int.Basic

abbrev default_get' := default_get (val_int 0)

scase in Ssreflect.Elim

partial def xsimp_step_r (xsimp : XSimpR) : TacticM Unit := do
  trace[xsimp] "RHS step"
  trace[xsimp] "hrt: {xsimp.hrt}"
  match xsimp.hlw, xsimp.hlt, xsimp.hrt with
  | `(hempty), `(hempty), `(@HStar.hStar hProp hProp $_ $_ $h $_) =>
     
    try
      trace[xsimp] "xsimp_r deals with: {h}"
      match h with
      | `(hempty) => {| apply xsimp_r_hempty |}
      | `(hpure $_) => {| apply xsimp_r_hpure |}
      | `(@HStar.hStar hProp hProp $_ $_ $h1 $h2) =>
        {| erw [@hstar_assoc $h1 $h2];
           simpNums |} 
                       
          
        xsimp_step_r (<- XSimpRIni)
      | `(@HWand.hWand hProp hProp $_ $_ $h1 $_) =>
        match h1 with
        | `(hpure $_) => {| apply xsimp_r_keep |}
        | _ => {| apply xsimp_r_hwand_same |}
      | `(htop) =>
        match xsimp.hrg with
        | `(hempty) =>
          {| apply xsimpl_r_hgc_or_htop |}
          repeat'' do
            xsimp_pick_same h xsimp.hla
            {| apply xsimp_lr_cancel_same |}
        | `(@HStar.hStar hProp hProp $_ $_ htop hempty) => {| apply xsimpl_r_htop_drop |}
        | _ => throwError "xsimp_step_r: @ unreachable"
      | `(@hexists $_ fun ($x:ident : $_) => $_) => xsimp_r_hexists_apply_hints x
      | `(protect $_) => {| apply xsimp_r_keep |}
      | `(hsingle $x $_) =>
        
        if x.isMVarStx then
          {| apply xsimp_r_keep |}
        else
          xsimp_pick_same_pointer x xsimp.hla
          
          
          {| apply xsimpl_lr_cancel_same_hsingle <;>
             xsimp_hsingle_discharge |}
      | _ =>
        if h.isMVarStx then
          {| apply xsimp_r_keep |}
        else
        xsimp_pick_same h xsimp.hla
        {| apply xsimp_lr_cancel_same |}
    catch ex =>
      trace[xsimp] ex.toMessageData
      {| apply xsimp_r_keep |}
  | _, _, _ => throwError "not implemented"

partial def getNestedApp (t :Expr) : Expr :=
  let_expr trm_app t _ := t | getVal t
  getNestedApp t

@[app_unexpander val_unit] def unexpandUnitL : Lean.PrettyPrinter.Unexpander
  | `($(_)) => `([lang| ()])

def xcahngeCore (l : Expr) : MVarId -> MetaM (List MVarId) := fun goal => do
  let goal <-
    match_expr <- goal.getType with
    | himpl _ _ => pure goal
    | qimpl _ _ _ => pure (<- goal.intro1P).2
    | _ => throwError "Expected a heap entailment"
  xchangeApply l goal

def hexists {A} (J : A → hProp) : hProp :=
  fun h => exists x, J x h

def qstar {A} (Q : A → hProp) (H : hProp) : A → hProp :=
  fun x => hstar (Q x) H

Lean.Name.mkSimple in Init.Prelude

Lean.explicitBinders in Init.NotationExtra

def getGoalProp : Lean.Elab.Tactic.TacticM Q(Prop) := do
  let goal ← Lean.Elab.Tactic.getMainTarget
  match ← castToProp goal with
  | some qType => return qType
  | none => throwError "goal is not a proposition"

def val_array_make : val := [lang|
  fun n v =>
    let m := n + 1 in
    alloc m as p in
    (val_set p) n ;
    (((val_array_fill p) 0) n) v ;
    p ]

def reducible (s : state) (t : trm) : Prop :=
  exists s' t', step s t s' t'

def hsingle (p : loc) (v : val) : hProp :=
  fun h => (h = Finmap.singleton p v)

scoped instance (priority := 1) EPCM : PartialCommMonoid val where
  valid := valid
  valid_add := by admit /- proof elided -/

inductive evalunop : prim → val → (val → Prop) → Prop where
  | evalunop_neg : forall b1,
      evalunop val_neg (val_bool b1) (fun v => v = val_bool (¬ b1))
  | evalunop_opp : forall n1,
      evalunop val_opp (val_int n1) (fun v => v = val_int (- n1))
  | evalunop_oppr : forall r1,
      evalunop val_opp (val_real r1) (fun v => v = val_real (- r1))

Finset.Ioo in Mathlib.Order.Interval.Finset.Defs

Lean.Name.cmp in Lean.Data.Name

def val_array_fill : val := [lang|
  fix f p i n v =>
    let b := n > 0 in
    if b then
      ((val_array_set p) i) v ;
      let m := n - 1 in
      let j := i + 1 in
      f p j m v
    end ]

def harray (L : List val) (p : loc) : hProp :=
  hheader (L.length) p ∗ hseg L p 0

def hadd [PartialCommMonoid val] (H₁ H₂ : hProp) : hProp :=
  fun h => exists h1 h2, H₁ h1 ∧ H₂ h2 ∧ h1 ⊥ʰ h2 ∧ h = h1 +ʰ h2

AList.lookup in Mathlib.Data.List.AList

def eval_like (t1 t2:trm) : Prop :=
  forall s Q, eval s t1 Q -> eval s t2 Q

def delabNoNotations :=
  (withOptions (fun _ =>
    (((KVMap.empty.insert
      `pp.all true).insert
      `pp.universes false).insert
      `pp.deepTerms true).insert
      `pp.fullNames true) $ PrettyPrinter.delab ·)

Nonempty in Init.Prelude

def haffine (_ : hProp) :=
  True

Int.toNat in Init.Data.Int.Basic

def qimpl {A} (Q1 Q2 : A → hProp) : Prop :=
  forall (v:A), Q1 v ==> Q2 v

local macro "LabType" : term => `(ℕ)

Prod.mk in Init.Prelude

def xsimp_pick (i : Nat) (last? : Bool) : TacticM Unit :=
   {| apply xsimp_pick_lemma
      · apply $(hstar_pick_lemma i last?) |}

def hstars_simp_post :=
  {| hsimp ; try apply himpl_refl |}

def xsimp_pick_applied (h hla : Term) : TacticM Unit := do
  let h <- Term.elabTerm h  none
  hstar_search hla fun i h' last? => do
    let h' <- Term.elabTerm h' none
    let numArgs + 1 := h'.getAppNumArgs' | throwError "not equal"
    let h' := h'.consumeMData.getAppPrefix numArgs
    let .true <-
      withAssignableSyntheticOpaque <| isDefEq h h' | throwError "not equal"
    xsimp_pick i last?

Iff in Init.Core

def labSet (l : ℕ) (s : Set α) : Set (Labeled α) := { ⟨l, x⟩ | x ∈ s }

shave in Ssreflect.Have

elab "#hint_xapp" thm:ident : command => do
  Command.runTermElabM fun _ => do
    let thm := (<- Term.elabTerm thm none)
    let .some thmName := thm.getAppFn.constName? | throwError "invalid theorem"
    let thm <- Meta.inferType thm
    let thmFun <- Meta.forallTelescope thm fun _ thm => do
      getTripleFun thm
    xappExtension.add (thmFun, thmName)

@[app_unexpander val_int] def unexpandInt : Lean.PrettyPrinter.Unexpander
  | `($(_) $n:num) => `($n:num)
  | `($(_) $n:ident) => `($n:ident)
  | `($(_) $n:term) => `(lang|⟨$n:term⟩)
  | _ => throw ( )

OfNat in Init.Prelude

Lean.Meta.inferType in Lean.Meta.Basic

def hforall {A} (J : A → hProp) : hProp :=
  fun h => forall x, J x h

List.keys in Mathlib.Data.List.Sigma

@[app_unexpander val_fix] def unexpandVFix : Lean.PrettyPrinter.Unexpander
  | `($(_) $f:str $x:str [lang| fun $xs* => $t]) =>
    let f := f.getString
    let x := x.getString
    let nameF := Lean.mkIdent $ Lean.Name.mkSimple f
    let nameX := Lean.mkIdent $ Lean.Name.mkSimple x
    `([lang| fix $nameF $nameX $xs* => $t])
  | `($(_) $f:str $x:str [lang| $t]) =>
    let f := f.getString
    let x := x.getString
    let nameF := Lean.mkIdent $ Lean.Name.mkSimple f
    let nameX := Lean.mkIdent $ Lean.Name.mkSimple x
    `([lang| fix $nameF $nameX => $t])
  | _ => throw ( )

def st1 : state := (Finmap.singleton 0 1).insert 1 1

Lean.Elab.Tactic.getMainTarget in Lean.Elab.Tactic.Basic

Finset.Icc in Mathlib.Order.Interval.Finset.Defs

Or in Init.Prelude

def htop : hProp :=
  hexists (fun (H : hProp) => H)

def evalExact_ref_nonpositive s x t1 t2 (Q : val → state → Prop) :=
  ∃ Q₁, evalExact s t1 Q₁ ∧
  (∀ v1 s1, Q₁ v1 s1 → ∀ p ∉ s1,
    (evalExact (s1.insert p v1) (subst x p t2) (fun v s ↦ Q v (s.erase p))))

def notstuck (s : state) (t : trm) : Prop :=
  trm_is_val t \/ reducible s t

AList in Mathlib.Data.List.AList

instance [PartialCommMonoid val] : AddCommMonoid hProp where
  zero := emp
  add  := hadd
  nsmul := nsmulRec
  add_comm  := by admit /- proof elided -/

instOfNatNat in Init.Prelude

List.zip in Init.Data.List.Basic

AddCommSemigroup in Mathlib.Algebra.Group.Defs

def trm_funs (xs:List var) (t:trm) : trm :=
  match xs with
  | [] => t
  | x1::xs' => trm_fun x1 (trm_funs xs' t)

def val_fixs (f:var) (xs:List var) (t:trm) : val :=
  match xs with
  | .nil => val_uninit
  | x1::xs' => val_fix f x1 (trm_funs xs' t)

List.length in Init.Prelude

List.Perm in Init.Data.List.Basic

Finset.Ico in Mathlib.Order.Interval.Finset.Defs

def val_abs : val := [lang|
  fun i =>
    let c := i < 0 in
    let m := 0 - 1 in
    let j := m * i in
    if c then j else i ]

Zero in Init.Prelude

def xchangeApply (l : Expr) : MVarId -> MetaM (List MVarId) := fun goal => do
  let g :: gs <- goal.applyConst `xchange_lemma | throwError "Expected a heap entailment"
  let gs' <- g.apply $ <- toHimp l
  return gs ++ gs'

def XSimpRIni : TacticM XSimpR := withMainContext do
  (<- getMainGoal).setTag `xsimp_goal
  let goal <- getGoalStxNN
  let `(XSimp $hl $hr) := goal | throwError "not a XSimp goal"
  let `(@Prod.mk hProp $_ $hla $hlwt) := hl | throwError "not a XSimp goal"
  let `(@Prod.mk hProp hProp $hlw $hlt) := hlwt | throwError "not a XSimp goal"
  let `(@Prod.mk hProp $_ $hra $hrgt) := hr | throwError "not a XSimp goal"
  let `(@Prod.mk hProp hProp $hrg $hrt) := hrgt | throwError "not a XSimp goal"
  return { hla := hla, hlw := hlw, hlt := hlt, hra := hra, hrg := hrg, hrt := hrt }

def purepostin (s : state) (P : val → Prop) (Q : val → state → Prop) : Prop :=
  
  forall v, P v → Q v s

def null : loc := 0

def pickTripleLemma : TacticM Name := do
  let n <- getTripleFun (<- getMainTarget)
  let .some thm := (xappExtension.getState (← getEnv)).find? n | throwError "no triple lemma found"
  return thm

Lean.Syntax in Init.Prelude

AList.insert in Mathlib.Data.List.AList

@[app_unexpander trm_ref] def unexpandRef : Lean.PrettyPrinter.Unexpander
  | `($(_) $x:str [lang| $t1] [lang| $t2]) =>
    let str := x.getString
    let name := Lean.mkIdent $ Lean.Name.mkSimple str
    `([lang| ref $name := $t1 in $t2])
  | _ => throw ( )

def wpgen_seq (F1 F2 : formula) : formula :=
  fun Q ↦ F1 (fun _ ↦ F2 Q)

local instance : HAdd ℤ ℤ val := ⟨fun x y => val.val_int (x + y)⟩

private def castToProp (e: Lean.Expr) : Lean.Elab.Tactic.TacticM (Option Q(Prop)) := do
  Qq.checkTypeQ (u := Lean.levelOne) e q(Prop)

def hstars_simp_step : TacticM Unit := withMainContext do
  let goal <- getGoalStxNN
  match goal with
    | `(himpl $Hl $Hr) =>
        match Hr with
          | `(@HStar.hStar hProp hProp $_ $_ $_ $hs) =>
              match hs with
              | `(@HStar.hStar hProp hProp $_ $_ $H $_) =>
                    try
                      xsimp_pick_same H Hl hstars_simp_pick ;
                      {| apply hstars_simp_cancel_lemma |}
                    catch ex =>
                      let s <- ex.toMessageData.toString
                      if s == "not equal" then
                        {| apply hstars_simp_keep_lemma |}
                      else
                        throw ex
              | _ => throwError "cannot simplify"
          | _ => throwError "cannot simplify"
    | _ => throwError "cannot simplify"

def make_list {A} (n : Nat) (v : A) : List A :=
  match n with
  | 0      => []
  | n' + 1 => v :: make_list n' v

Finmap.singleton in Mathlib.Data.Finmap

def purepost (s : state) (P : val → Prop) : val → state → Prop :=
  fun v s' => P v ∧ s' = s

def hpure (P : Prop) : hProp :=
  hexists (fun (_ : P) => emp)

local instance : HAdd ℤ ℕ val := ⟨fun x y => (x + (y : Int))⟩

Lean.unbracketedExplicitBinders in Init.NotationExtra

List.kerase in Mathlib.Data.List.Sigma

@[app_unexpander hexists] def unexpandHExists : Lean.PrettyPrinter.Unexpander
  | `($(_) fun $x:ident => ∃ʰ $xs:binderIdent*, $b) => `(∃ʰ $x:ident $xs:binderIdent*, $b)
  | `($(_) fun $x:ident => $b)                     => `(∃ʰ $x:ident, $b)
  | `($(_) fun ($x:ident : $t) => $b)              => `(∃ʰ ($x:ident : $t), $b)
  | t                                              => pure t

local instance : HAdd ℕ ℤ val := ⟨fun x y => ((x : Int) + y)⟩

Finmap.liftOn₂ in Mathlib.Data.Finmap

def wpgen_ref (x : var) (t1 t2 : trm) : formula :=
  fun Q ↦ ∃ʰ v, ⌜t1 = trm_val v⌝ ∗
    h∀ p, (p ~~> v) -∗ protect (wp (subst x p t2) (fun hv ↦ Q hv ∗ ∃ʰ u, p ~~> u))

instance : Coe (List var) (List trm) where
  coe := trms_vals

Lean.Meta.isDefEq in Lean.Meta.Basic

def subst (y : var) (v' : val) (t : trm) : trm :=
  
  let if_y_eq x t1 t2 := if x = y then t1 else t2
  match t with
  | trm_val v          => trm_val v
  | trm_var x          => if_y_eq x (trm_val v') t
  | trm_fun x t1       => trm_fun x (if_y_eq x t1 (subst y v' t1))
  | trm_fix f x t1     => trm_fix f x (if_y_eq f t1 (if_y_eq x t1 (subst y v' t1)))
  | trm_app t1 t2      => trm_app (subst y v' t1) (subst y v' t2)
  | trm_seq t1 t2      => trm_seq (subst y v' t1) (subst y v' t2)
  | trm_let x t1 t2    => trm_let x (subst y v' t1) (if_y_eq x t2 (subst y v' t2))
  | trm_if t0 t1 t2    => trm_if (subst y v' t0) (subst y v' t1) (subst y v' t2)
  | trm_for x t1 t2 t3 => trm_for x (subst y v' t1) (subst y v' t2) (if_y_eq x t3 (subst y v' t3))
  | trm_while t1 t2    => trm_while (subst y v' t1) (subst y v' t2)
  | trm_ref x t1 t2    => trm_ref x (subst y v' t1) (if_y_eq x t2 (subst y v' t2))
  | trm_alloc x t1 t2  => trm_alloc x (subst y v' t1) (if_y_eq x t2 (subst y v' t2))

class PartialCommMonoidWRT (α : Type) (add' : semiOutParam (α -> α -> α)) (valid' : semiOutParam (α -> Prop)) extends PartialCommMonoid α where
  addE : (· + ·) = add'
  validE : PartialCommMonoid.valid = valid'

Unit in Init.Prelude

Set in Mathlib.Data.Set.Defs

L in Archive.Hairer

instance (priority := low) : Zero hProp := ⟨emp⟩

Lean.Meta.unhygienic in Batteries.Lean.Meta.Basic

def wpgen_for (v₁ v₂ : trm) (F1 : val -> formula) : formula :=
  mkstruct fun Q =>
    ∃ʰ n₁ n₂ : Int, ⌜v₁ = n₁⌝ ∗ ⌜v₂ = n₂⌝ ∗
      h∀ (S : Int -> formula),
        (let F i :=
          if i < n₂ then
            wpgen_seq (F1 (val_int i)) (S (i + 1))
          else wpgen_val val_unit
        ⌜structural_pred S /\ ∀ i, F i ===> S i⌝ -∗ S n₁ Q )

instHAdd in Init.Prelude

@[app_unexpander trm_let] def unexpandLet : Lean.PrettyPrinter.Unexpander
  | `($(_) $x:str [lang| $t1] [lang| $t2]) =>
    let str := x.getString
    let name := Lean.mkIdent $ Lean.Name.mkSimple str
    `([lang| let $name := $t1 in $t2])
  | _ => throw ( )

macro "∃ʰ" xs:Lean.explicitBinders ", " b:term : term => Lean.expandExplicitBinders ``hexists xs b

def wpgen_while (F1 F2 : formula) : formula := mkstruct fun Q =>
  h∀ R : formula,
    let F := wpgen_if_trm F1 (wpgen_seq F2 R) (wpgen_val val_unit)
    ⌜structural R ∧ F ===> R⌝ -∗ R Q

def xsimp_r_hexists_apply_hints (x : Ident) : TacticM Unit := do
  let hints <- hintExt.getSSR
  match hints with
  | [] =>
    trace[xsimp] "no hints"
    eApplyAndName `xsimp_r_hexists $ `xsimp ++ x.getId
  | h :: hs =>
    hintExt.setSSR hs
    match h with
    | `(hint| ?)       => eApplyAndName `xsimp_r_hexists $ `xsimp ++ x.getId
    | `(hint| $t:term) => {| apply (@xsimp_r_hexists _ $t) |}
    | _ => throwError "xsimp_r_hexists_apply_hints: @ unreachable"

Lean.pp.deepTerms in Lean.PrettyPrinter.Delaborator.Options
</all_available_defs>

<all_available_lemmas>
lemma hstars_simp_pick_lemma :
  H1 = H1' →
  H1' ==> H2 →
  H1 ==> H2

@[ext]
lemma hProp.ext (H1 H2 : hProp) :
  (∀ h, H1 h ↔ H2 h) → H1 = H2

lemma wpgen_seq_sound F1 F2 t1 t2 :
  formula_sound t1 F1 →
  formula_sound t2 F2 →
  formula_sound (trm_seq t1 t2) (wpgen_seq F1 F2)

lemma triple_div n1 n2 :
  n2 ≠ 0 →
  triple (trm_app val_div (val_int n1) (val_int n2))
    emp
    (fun r ↦ ⌜r = val_int (n1 / n2)⌝)

lemma wp_ramified t (Q1 Q2 : val -> hProp) :
  (wp t Q1) ∗ (Q1 -∗ Q2) ==> (wp t Q2)

theorem diff_non_mem (h₁ h₂ : state) :
  p ∈ h₂ → p ∉ h₁ \ h₂

lemma xwhile_inv_lemma (I : Bool -> α -> hProp)
  (F1 F2 : formula) :
    WellFounded R ->
    (H ==> ∃ʰ b a, I b a) ->
    (∀ (S: formula) b X, structural S ->
        (∀ b a', R a' X -> (I b a') ==> S fun _ => ∃ʰ a, I false a) ->
        I b X ==> wpgen_if_trm F1 (wpgen_seq F2 S) (wpgen_val val_unit) fun _ => ∃ʰ a, I false a) ->
    H ==> wpgen_while F1 F2 (fun _ => ∃ʰ a, I false a)

lemma erase_of_non_mem (h : state) :
  p ∉ h →
  h.erase p = h

lemma eval_like_trm_apps_funs (heqv0 : v0 = trm_funs xs t1) :
  eval_like (isubst (xs.mkAlist vs) t1) (trm_apps (val_funs xs t1) ts)

lemma cons_app {A : Type} (l1 l2 : List A) (x : A) :
  x :: l1 ++ l2 = x :: (l1 ++ l2)

lemma wp_val v Q :
  Q v ==> wp (trm_val v) Q

lemma frame_eq_rw :
  s.Disjoint h2 →
  (fun v' s' ↦ v' = v ∧ s' = s ∪ h2) =
  (qstar (fun v' s' ↦ v' = v ∧ s' = s) (tohProp (fun h ↦ h = h2)))

lemma haffine_hastar_hpure (P : Prop) H :
  (P → haffine H) →
  haffine (⌜P⌝ ∗ H)

lemma sP'_strongest :
  eval h t Q → sP' h t ===> Q

lemma triple_gtr r1 r2 :
  triple (trm_app val_gt (val_real r1) (val_real r2))
    emp
    (fun r ↦ ⌜r = val_bool (r1 > r2)⌝)

@[heapSimp]
lemma foo'' : (@OfNat.ofNat val n _) = val.val_int (n : ℤ)

lemma conseq_ind (n : ℕ) (v : val) (p : loc) :
  x ∈ conseq (make_list n v) p → x ≥ p

lemma hstar_pick_last_9 :
  h1 ∗ h2 ∗ h3 ∗ h4 ∗ h5 ∗ h6 ∗ h7 ∗ h8 ∗ h9 = h9 ∗ h1 ∗ h2 ∗ h3 ∗ h4 ∗ h5 ∗ h6 ∗ h7 ∗ h8

lemma triple_gt n1 n2 :
  triple (trm_app val_gt (val_int n1) (val_int n2))
    emp
    (fun r ↦ ⌜r = val_bool (n1 > n2)⌝)

lemma himpl_lr_refl :
  XSimp (hla, emp, emp) (hla, emp, emp)

lemma triple_app_fix v1 v2 f x t1 H Q :
  v1 = val_fix f x t1 →
  triple (subst x v2 (subst f v1 t1)) H Q →
  triple (trm_app v1 v2) H Q

lemma xfun_nospec_lemma  H Q Fof :
(forall (vf : val),
    (forall (vx : val) H' Q', (H' ==> Fof vx Q') → triple (trm_app vf vx) H' Q') →
    (H ==> Q vf)) →
H ==> wpgen_fun Fof Q

lemma sum_single'' (v : β -> Int) (fs : Finset β)  :
  fs.Nonempty ->
  ∑ i in fs, (p ~~> v i) = p ~~> val.val_int (∑ i in fs, v i)

lemma hsingle_intro p v :
  (p ~~> v) (Finmap.singleton p v)

lemma hseg_cons v p j L :
  hseg (v :: L) p j = hcell v p j ∗ hseg L p (j + 1)

lemma set_out_of_bounds (L : List val) i v :
  i < 0 ∨ i ≥ L.length →
  L.set i v = L

lemma hind_any h : ⊤⊤ h

lemma qwand_cancel A (Q1 Q2 : A → hProp) :
  Q1 ∗ (Q1 -∗ Q2) ===> Q2

lemma eval_like_trm_funs_val_funs xs t : xs ≠ [] → eval_like (trm_funs xs t) (val_funs xs t)

lemma triple_sub n1 n2 :
  triple (trm_app val_sub (val_int n1) (val_int n2))
    emp
    (fun r ↦ ⌜r = val_int (n1 - n2)⌝)

lemma xsimpl_lr_cancel_htop :
  XSimp (Hla, Hlw, Hlt) (Hra, (⊤ ∗ Hrg), Hrt) ->
  XSimp ((H ∗ Hla), Hlw, Hlt) (Hra, (⊤ ∗ Hrg), Hrt)

@[simp]
lemma Heap.add_single (v v' : val) [PartialCommMonoid val] :
  (Finmap.singleton p v) +ʰ (Finmap.singleton p v') = (Finmap.singleton p (v + v'))

lemma triple_for_raw (x:var) (n1 n2: Int) t3 H (Q:val->hProp) :
  triple (
    if (n1 < n2)
      then (trm_seq (subst x n1 t3) (trm_for x (val_int $ n1+1) n2 t3))
      else val_unit) H Q ->
  triple (trm_for x n1 n2 t3) H Q

lemma list_middle_inv (A : Type) (n : Nat) (l : List A) :
  n < l.length →
  exists (x : A) (l1 l2 : List A),
    l = l1 ++ x :: l2 ∧ l1.length = n

lemma xsimp_lr_hwand_hfalse :
  XSimp (Hla, emp, emp) ((⌜False⌝ -∗ H1) ∗ emp, emp, emp)

lemma sP_strongest :
  eval h t Q -> sP h t ===> Q

lemma hstar_flip_8 :
  h1 ∗ h2 ∗ h3 ∗ h4 ∗ h5 ∗ h6 ∗ h7 ∗ h8 ∗ emp =
  h8 ∗ h7 ∗ h6 ∗ h5 ∗ h4 ∗ h3 ∗ h2 ∗ h1 ∗ emp

lemma hstar_inv (H1 H2 : hProp) h:
  (H1 ∗ H2) h →
  exists h1 h2, H1 h1 ∧ H2 h2 ∧ Finmap.Disjoint h1 h2 ∧ h = h1 ∪ h2

lemma hstar_pick_last_6 :
  h1 ∗ h2 ∗ h3 ∗ h4 ∗ h5 ∗ h6 = h6 ∗ h1 ∗ h2 ∗ h3 ∗ h4 ∗ h5

lemma lookup_diff (h₁ h₂ : state) :
  p ∉ h₂ →
  (h₁ \ h₂).lookup p = h₁.lookup p

lemma wp_app_fix f x v1 v2 t1 Q :
  v1 = val_fix f x t1 →
  wp (subst x v2 (subst f v1 t1)) Q ==> wp (trm_app v1 v2) Q

lemma triple_if (b : Bool) t1 t2 H Q :
  triple (if b then t1 else t2) H Q →
  triple (trm_if b t1 t2) H Q

lemma triple_subr r1 r2 :
  triple (trm_app val_sub (val_real r1) (val_real r2))
    emp
    (fun r ↦ ⌜r = val_real (r1 - r2)⌝)

lemma AList_erase_entries (l : @AList loc (fun _ ↦ val)) :
  (l.erase p).entries = (l.entries).kerase p

lemma keys_eq_not_mem_r (h1 h2 : state) :
  h1.keys = h2.keys →
  p ∉ h2 →
  p ∉ h1

lemma triple_neg (b1 : Bool) :
  triple (trm_app val_neg b1)
    emp
    (fun r ↦ ⌜r = val_bool (¬b1)⌝)

lemma triple_lt n1 n2 :
  triple (trm_app val_lt (val_int n1) (val_int n2))
    emp
    (fun r ↦ ⌜r = val_bool (n1 < n2)⌝)

lemma xsimp_l_acc_other :
  XSimp (h ∗ hla, hlw, hlt) hr ->
  XSimp (hla, hlw, h ∗ hlt) hr

lemma eval_like_val_fun_trm_fun x t : eval_like (val_fun x t) (trm_fun x t)

lemma hseg_nil p j :
  hseg [] p j = emp

lemma hrange_eq_conseq (L : List val) (n : ℤ) (p : loc) (s : state) :
  L.length = n →
  hrange L p s →
  s.keys = (conseq (make_list n.natAbs val_uninit) p).keys

lemma non_mem_diff_helper2 (h₁ : state) (l : @AList loc fun _ ↦ val) :
  p ∈ List.foldl (fun d s ↦ Finmap.erase s.fst d) (Finmap.erase a h₁) l.entries →
  p ∈ List.foldl (fun d s ↦ Finmap.erase s.fst d) h₁ l.entries

lemma wp_structural : structural (wp t)

lemma evalExact_sP' :
  evalExact h t Q → evalExact h t (sP' h t)

lemma triple_seq t1 t2 H Q H1 :
  triple t1 H (fun _ ↦ H1) →
  triple t2 H1 Q →
  triple (trm_seq t1 t2) H Q

lemma mkstruct_monotone F1 F2 Q :
  (forall Q, F1 Q ==> F2 Q) →
  mkstruct F1 Q ==> mkstruct F2 Q

lemma insert_frame :
  s.Disjoint h2 →
  p ∈ s →
  fun v'' s' ↦ v'' = val_unit ∧ s' = Finmap.insert p v' (s ∪ h2) =
  (qstar (fun v'' s' ↦ v'' = val_unit ∧ s' = Finmap.insert p v' s) (tohProp fun h ↦ h = h2))

lemma evalExact_sat :
  evalExact s t Q → ∃ v s, Q v s

lemma triple_alloc (n : Int) :
  n ≥ 0 →
  (∀ (p : loc), triple (subst x p t)
    (H ∗ ⌜p ≠ null⌝ ∗ hrange (make_list n.natAbs val_uninit) p)
    (Q ∗ ⌜p ≠ null⌝  ∗ ∃ʰ L, ⌜L.length = n⌝ ∗ hrange L p) ) →
  triple (trm_alloc x n t) H Q

lemma xval_lemma v H Q :
  H ==> Q v →
  H ==> wpgen_val v Q

lemma wp_fix f x t Q :
  Q (val_fix f x t) ==> wp (trm_fix f x t) Q

lemma triple_array_set_hseg L (p : loc) (i j : Int) (v : val) :
  0 <= i - j ∧ i - j < L.length →
  triple (trm_app val_array_set p i v)
    (hseg L p j)
    (fun _ ↦ hseg (L.set (Int.natAbs (i - j)) v) p j)

lemma triple_le n1 n2 :
  triple (trm_app val_le (val_int n1) (val_int n2))
    emp
    (fun r ↦ ⌜r = val_bool (n1 <= n2)⌝)

lemma wp_equiv t H Q :
  (H ==> wp t Q) ↔ triple t H Q

lemma xsimp_l_cancel_hwand_hstar :
  XSimp (Hla, Hlw, (H2 -∗ H3) ∗ Hlt) HR →
  XSimp ((H1 ∗ Hla), (((H1 ∗ H2) -∗ H3) ∗ Hlw), Hlt) HR

lemma hforall_specialize A (x : A) (J : A → hProp) :
  (hforall J) ==> (J x)

lemma keys_eq_not_mem_l (h1 h2 : state) :
  h1.keys = h2.keys →
  p ∉ h1 →
  p ∉ h2

lemma xsimp_r_hempty :
  XSimp hl (hra, hrg, hrt) ->
  XSimp hl (hra, hrg, emp ∗ hrt)

lemma harray_eq p L :
  harray L p = ∃ʰ n, ⌜n = L.length⌝ ∗ hheader n p ∗ hseg L p 0

lemma eval_divr s r1 r2 Q :
  r2 ≠ 0 ->
  Q (val_real (r1 / r2)) s ->
  eval s (trm_app (trm_app val_div (val_real r1)) (val_real r2)) Q

lemma harray_focus i L p (v : 0 <= i ∧ i < L.length) :
  0 <= i ∧ i < L.length →
  harray L p ==>
  hcell L[Int.natAbs i]! p i
    ∗ (h∀ w, hcell w p i -∗ harray (L.set (Int.natAbs i) w) p)

lemma hstar_pick_3 :
  h1 ∗ h2 ∗ h3 ∗ h = h3 ∗ h1 ∗ h2 ∗ h

lemma wp_sound t :
  formula_sound t (wp t)

lemma wpgen_fun_sound x t1 Fof :
  (forall vx, formula_sound (subst x vx t1) (Fof vx)) →
  formula_sound (trm_fun x t1) (wpgen_fun Fof)

lemma hwand_hempty_l H :
  (emp -∗ H) = H

lemma hstar_flip_3 :
  h1 ∗ h2 ∗ h3 ∗ emp = h3 ∗ h2 ∗ h1 ∗ emp

lemma in_read_union_l (h1 h2 : state) (x : loc) :
  x ∈ h1 → read_state x (h1 ∪ h2) = read_state x h1

lemma remove_disjoint_union_l (h1 h2 : state) (x : loc) :
  x ∈ h1 → Finmap.Disjoint h1 h2 →
  Finmap.erase x (h1 ∪ h2) = Finmap.erase x h1 ∪ h2

lemma xsimpl_lr_qwand_unit (Q1 Q2 : Unit -> hProp) :
  XSimp (emp, emp, (Q1 ( ) ∗ Hla)) (emp, emp, (Q2 ( ) ∗ emp)) ->
  XSimp (Hla, emp, emp) ((Q1 -∗ Q2) ∗ emp, emp, emp)

lemma validInter_comm (h₁ h₂ : heap) :
  h₁ ⊥ʰ h₂ = h₂ ⊥ʰ h₁

lemma himpl_hstar_hpure_r P H H' :
   P →
   (H ==> H') →
   H ==> ⌜P⌝ ∗ H'

lemma int_eq_sub (l m n : ℤ) :
  l + m = n → l = n - m

lemma insert_eq_union_single (h : state) :
  p ∉ h →
  h.insert p v = h ∪ (Finmap.singleton p v)

lemma xsimp_lr_cancel_same :
  XSimp (hla, hlw, hlt) (hra, hrg, hrt) ->
  XSimp (h ∗ hla, hlw, hlt) (hra, hrg, h ∗ hrt)

lemma hstar_hpure_r P H h :
  (H ∗ ⌜P⌝) h = (H h ∧ P)

lemma val_funs_snoc (xs : List var) (x : var) (h : xs ≠ []) (t : trm) :
  val_funs (xs ++ [x]) t = val_funs xs (trm_fun x t)

@[simp]
lemma kmerge_empty_r (l : List (Sigma (fun _ : loc => val))) : kmerge l [] = l

lemma intersect_disjoint_cancel (s₁ s₂ s₃ : state) :
  s₁.Disjoint s₃ →
  (s₁ ∪ intersect s₂ s₃) \ s₃ = s₁

lemma triple_hpure' t (P : Prop) Q :
  (P → triple t emp Q) →
  triple t ⌜P⌝ Q

lemma hforall_intro A (J : A → hProp) h :
  (forall x, J x h) → (hforall J) h

lemma non_mem_diff_helper1 (h₁ : state) (l : @AList loc fun _ ↦ val) :
  a ∉ l →
  p ∈ List.foldl (fun d s ↦ Finmap.erase s.fst d) (Finmap.erase a h₁) l.entries →
  p ≠ a

lemma hstar_flip_2 :
  h1 ∗ h2 ∗ emp = h2 ∗ h1 ∗ emp

lemma hwand_uncurry H1 H2 H3 :
  H1 -∗ (H2 -∗ H3) ==> (H1 ∗ H2) -∗ H3

lemma findIdx_spec' (arr : loc) (f : Int -> ℝ)
  (z n : ℤ) (_ : z <= n) (_ : 0 <= z) (N : ℕ) (_ : n <= N) :
  Set.InjOn f ⟦z, n⟧ ->
  i ∈ ⟦z, n⟧ ->
  { arr(arr, x in N => f x) }
  [ findIdx arr ⟨f i⟩ z n ]
  { v, ⌜ v = i ⌝ ∗ arr(arr, x in N => f x) }

lemma xsimpl_lr_qwand α (Q1 Q2 : α -> hProp) :
  (forall x, XSimp (emp, emp, (Q1 x ∗ Hla)) (emp, emp, (Q2 x ∗ emp))) ->
  XSimp (Hla, emp, emp) (((Q1 -∗ Q2) ∗ emp), emp, emp)

lemma triple_array_set_hcell (p : loc) (i : Int) (v w : val) :
  triple (trm_app val_array_set p i v)
    (hcell w p i)
    (fun _ ↦ hcell v p i)

lemma lookup_intersect (s₁ s₂ : state) :
  p ∈ s₁ ∧ p ∈ s₂ →
  (intersect s₁ s₂).lookup p = s₁.lookup p

lemma add_pointer_spec (p q : loc) (n m : Int) (_ : m >= 0) :
  { p ~~> n ∗ q ~~> m }
  [ add_pointer p q ]
  { v, ⌜v = n+m⌝ ∗ ⊤  }

lemma Option.merge_none_r (a : Option α) : Option.merge f a none = a

lemma triple_conseq t H' Q' H Q :
  triple t H' Q' →
  H ==> H'→
  Q' ===> Q →
  triple t H Q

lemma union_singleton_eq_insert (h : state) :
  Finmap.singleton p v ∪ h = h.insert p v

lemma List.not_nil_snoc {α : Type u} (l : List α) : l ≠ [] → ∃ l' x, l = l' ++ [x]

lemma remove_not_in_r (h1 h2 : state) (p : loc) :
  p ∉ h2 →
  (h1 ∪ h2).erase p = h1.erase p ∪ h2

lemma hstar_flip_1 :
  h1 ∗ emp = h1 ∗ emp

lemma validInter_assoc_l (h₁ h₂ h₃ : heap) :
  h₁ ⊥ʰ h₂ -> (h₁ +ʰ h₂) ⊥ʰ h₃ -> h₁ ⊥ʰ (h₂ +ʰ h₃)

lemma val_int_congr :
  n1 = n2 →
  val.val_int n1 = val.val_int n2

lemma hstar_flip_10 :
  h1 ∗ h2 ∗ h3 ∗ h4 ∗ h5 ∗ h6 ∗ h7 ∗ h8 ∗ h9 ∗ h10 ∗ emp =
  h10 ∗ h9 ∗ h8 ∗ h7 ∗ h6 ∗ h5 ∗ h4 ∗ h3 ∗ h2 ∗ h1 ∗ emp

lemma triple_ger r1 r2 :
  triple (trm_app val_ge (val_real r1) (val_real r2))
    emp
    (fun r ↦ ⌜r = val_bool (r1 >= r2)⌝)

@[simp]
lemma Heap.add_mem (h₁ h₂ : heap) : (l ∈  h₁ +ʰ h₂) = (l ∈ h₁ ∨ l ∈ h₂)

lemma triple_conseq_frame H2 H1 Q1 t H Q :
  triple t H1 Q1 →
  H ==> H1 ∗ H2 →
  Q1 ∗ H2 ===> Q →
  triple t H Q

lemma hstar_hempty_r H :
  H ∗ emp = H

lemma himpl_frame_l H1 H1' H2 :
  H1 ==> H1' →
  (H1 ∗ H2) ==> (H1' ∗ H2)

lemma mkstruct_erase Q F :
  F Q ==> mkstruct F Q

lemma himpl_frame_r H1 H2 H2' :
  H2 ==> H2' →
  (H1 ∗ H2) ==> (H1 ∗ H2')

lemma hstar_pick_1 :
  h1 ∗ h = h1 ∗ h

lemma qstar_simp (Q1 : α -> hProp) :
  (Q1 ∗ H) x = Q1 x ∗ H

lemma insert_disjoint_l (h1 h2 : state) (x : loc) (v : val) :
  h2.Disjoint (h1.insert x v) →
  x ∉ h2 ∧ h2.Disjoint h1

lemma wpgen_let_sound F1 F2of x t1 t2 :
  formula_sound t1 F1 →
  (forall v, formula_sound (subst x v t2) (F2of v)) →
  formula_sound (trm_let x t1 t2) (wpgen_let F1 F2of)

lemma hadd_single (v v' : ℝ) :
  (p ~~> val.val_real v) + (p ~~> val.val_real v') = p ~~> val.val_real (v + v')

lemma xsimp_r_keep :
  XSimp hl (h ∗ hra, hrg, hrt) ->
  XSimp hl (hra, hrg, h ∗ hrt)

lemma hpure_intro_hempty P h :
  emp h → P → ⌜P⌝ h

lemma triple_unop op v1 (P : val → Prop) :
  evalunop op v1 P →
  triple (trm_app op v1) emp (fun r ↦ ⌜P r⌝)

lemma disjoint_insert_l (h1 h2 : state) (x : loc) (v : val) :
  Finmap.Disjoint h1 h2 →
  x ∈ h1 →
  Finmap.Disjoint (Finmap.insert x v h1) h2

lemma qwand_equiv H A (Q1 Q2 : A → hProp) :
  H ==> (Q1 -∗ Q2) ↔ (Q1 ∗ H) ===> Q2

lemma triple_oppr r1 :
  triple (trm_app val_opp (val_real r1))
    emp
    (fun r ↦ ⌜r = val_real (-r1)⌝)

lemma hseg_eq_hrange L p (k : Nat) :
  hseg L p k = hrange L (p + 1 + k)

lemma haffine_hempty : haffine emp

lemma union_difference_id (h₁ h₂ : state) :
  h₁.Disjoint h₂ →
  (h₁ ∪ h₂) \ h₂ = h₁

lemma xsimp_l_hpure :
  (p -> XSimp (hla, hlw, hlt) hr) ->
  XSimp (hla, hlw, ⌜p⌝ ∗ hlt) hr

lemma qwandE α (Q1 Q2 : α → hProp) :
  Q1 -∗ Q2 = hforall (fun x => (Q1 x) -∗ (Q2 x))

lemma disjoint_single (h : state) :
  p ∉ h →
  h.Disjoint (Finmap.singleton p v)

lemma structural_imp : structural F ->
  Q ===> Q' -> F Q ==> F Q'

lemma isubst_empty t : isubst ∅ t = t

lemma hstar_pick_2  :
  h1 ∗ h2 ∗ h = h2 ∗ h1 ∗ h

lemma triple_hforall t A (x : A) (J : A → hProp) Q:
  triple t (J x) Q →
  triple t (hforall J) Q

lemma wp_frame t H Q :
  (wp t Q) ∗ H ==> wp t (Q ∗ H)

lemma triple_array_set L (p : loc) (i : Int) (v : val) :
  0 <= i ∧ i < L.length →
  triple (trm_app val_array_set p i v)
    (harray L p)
    (fun _ ↦ harray (L.set (Int.natAbs i) v) p)

@[disjE]
lemma disjoint_label_set :
  Disjoint ⟪l,s⟫ ⟪l',s'⟫ ↔ l ≠ l' ∨ Disjoint s s'

lemma hProp.disjoint_hstar (H₁ H₂ H₃ : hProp) :
  (H₃.Disjoint H₁ ∧ H₃.Disjoint H₂) -> H₃.Disjoint (H₁ ∗ H₂)

@[heapSimp]
lemma foo' : (@OfNat.ofNat ℤ n _) = (n : ℤ)

lemma union_monotone_r (s₃ s₁ s₂ : state) :
  s₁ = s₂ →
  s₁ ∪ s₃ = s₂ ∪ s₃

lemma himpl_hexists_r A (x : A) H (J : A → hProp) :
  (H ==> J x) →
  H ==> (hexists J)

lemma wp_if (b : Bool) t1 t2 Q :
  wp (if b then t1 else t2) Q ==> wp (trm_if b t1 t2) Q

lemma wp_app_fun x v1 v2 t1 Q :
  v1 = val_fun x t1 →
  wp (subst x v2 t1) Q ==> wp (trm_app v1 v2) Q

lemma xstruct_lemma F H Q :
  H ==> F Q →
  H ==> mkstruct F Q

lemma triple_arrayFun_length (p : loc) :
  triple (trm_app val_array_length p)
    (harrayFun f n p)
    (fun r ↦ ⌜r = val_int n⌝ ∗ harrayFun f n p)

lemma hstars_simp_start_lemma :
  H1 ∗ emp ==> emp ∗ H2 ∗ emp →
  H1 ==> H2

lemma hstar_pick_last_1 :
  h1 = h1

lemma evalExact_frame_val (v : val) (s h2 : state) :
  s.Disjoint h2 →
  evalExact (s ∪ h2) t (fun v' s' ↦ v' = v ∧ s' = s ∪ h2) →
  evalExact (s ∪ h2) t
    (qstar (fun v' s' ↦ v' = v ∧ s' = s) (tohProp (fun h ↦ h = h2)))

@[simp]
lemma himpl_refl_resolve  H : (H ==> H) = True

lemma hstar_htop_htop :
  ⊤ ∗ ⊤ = ⊤

lemma update_app_r {A : Type} (l1 l2 : List A) n v :
  n ≥ l1.length →
  (l1 ++ l2).set n v = l1 ++ l2.set (n - l1.length) v

lemma eval_like_val_fun_trm_fun_app_left (x : var) (t1 t2 : trm) :
  eval_like (trm_app (val_fun x t1) t2) (trm_app (trm_fun x t1) t2)

lemma himpl_hempty_hwand_same H :
  emp ==> (H -∗ H)

lemma hstar_hgc_hgc : /GC ∗ /GC = /GC

lemma triple_mul n1 n2 :
  triple (trm_app val_mul (val_int n1) (val_int n2))
    emp
    (fun r ↦ ⌜r = val_int (n1 * n2)⌝)

lemma hstar_intro (H1 H2 : hProp) h1 h2 :
  H1 h1 →
  H2 h2 →
  Finmap.Disjoint h1 h2 →
  (H1 ∗ H2) (h1 ∪ h2)

lemma qimpl_refl (Q : α -> hProp) : Q ===> Q

lemma steps_trans s1 s2 s3 t1 t2 t3 :
  steps s1 t1 s2 t2 →
  steps s2 t2 s3 t3 →
  steps s1 t1 s3 t3

lemma haffine_hany : forall H,
  haffine H

lemma mkstruct_ramified Q1 Q2 F :
  (mkstruct F Q1) ∗ (Q1 -∗ Q2) ==> (mkstruct F Q2)

lemma triple_ler r1 r2 :
  triple (trm_app val_le (val_real r1) (val_real r2))
    emp
    (fun r ↦ ⌜r = val_bool (r1 <= r2)⌝)

lemma xfor_lemma (z n : ℤ) (x : var) (I : ℤ -> hProp) :
  z <= n ->
  (H ==> H' ∗ I z) ->
  (∀ i, z <= i -> i < n -> I i ==> wp (subst x i F1) (fun _ => I (i + 1))) ->
  ((fun _ => I n ∗ H') ===> Q) ->
  H ==> wp (trm_for x z n F1) Q

@[simp]
lemma labSet_diff (l : ℕ) (s s' : Set α) :
   ⟪l, s⟫ \ ⟪l, s'⟫ = ⟪l, s \ s'⟫

lemma finite_state' n (s : state) :
  ∃ p, p ≠ null ∧
    Finmap.Disjoint s (conseq (make_list n val_uninit) p)

lemma hexists_intro A (x : A) (J : A → hProp) h :
  J x h → (hexists J) h

lemma wp_of_wpgen :
  H ==> wpgen t Q →
  H ==> wp t Q

lemma xsimp_l_hempty :
  XSimp (hla, hlw, hlt) hr ->
  XSimp (hla, hlw, emp ∗ hlt) hr

lemma eval_addr s r1 r2 Q :
  Q (val_real (r1 + r2)) s →
  eval s (trm_app (trm_app val_add (val_real r1)) (val_real r2)) Q

lemma himpl_hstar_trans_l H1 H2 H3 H4 :
  H1 ==> H2 →
  H2 ∗ H3 ==> H4 →
  H1 ∗ H3 ==> H4

lemma hwandE :
  H1 -∗ H2 = hexists (fun H0 => H0 ∗ hpure ((H1 ∗ H0) ==> H2))

lemma xseq_lemma H F1 F2 Q :
  H ==> F1 (fun _ => F2 Q) →
  H ==> wpgen_seq F1 F2 Q

lemma himpl_hgc_r : forall H,
  haffine H →
  H ==> /GC

lemma himpl_frame_lr H1 H1' H2 H2' :
  H1 ==> H1' →
  H2 ==> H2' →
  (H1 ∗ H2) ==> (H1' ∗ H2')

lemma AList.erase_noop {α : Type u} {β : α → Type v} [DecidableEq α] (a : α) (l : AList β) :
    a ∉ l → (AList.erase a l).entries.Perm l.entries

lemma hexists_inv A (J : A → hProp) h :
  (hexists J) h → exists x, J x h

lemma triple_array_get_hcell (p : loc) (i : Int) (v : val) :
  triple [lang| val_array_get p i]
    (hcell v p i)
    (fun r ↦ ⌜r = v⌝ ∗ hcell v p i)

lemma eval_app_arg2' : forall s1 (v1 : val) t2 Q1 Q,
  eval s1 t2 Q1 ->
  (forall v2 s2, eval s2 (trm_app v1 v2) Q) ->
  eval s1 (trm_app v1 t2) Q

lemma himpl_hwand_r H1 H2 H3 :
  H2 ∗ H1 ==> H3 →
  H1 ==> (H2 -∗ H3)

lemma mkstruct_frame F H Q :
  (mkstruct F Q) ∗ H ==> mkstruct F (Q ∗ H)

lemma xlet_lemma H F1 F2of Q :
  H ==> F1 (fun v => F2of v Q) →
  H ==> wpgen_let F1 F2of Q

lemma erase_disjoint (h1 h2 : state) (p : loc) :
  h1.Disjoint h2 →
  (h1.erase p).Disjoint h2

lemma xsimp_l_hwand_reorder :
  h1 = h1' ->
  XSimp (hla, ((h1' -∗ h2) ∗ hlw), hlt) hr ->
  XSimp (hla, (h1 -∗ h2) ∗ hlw, hlt) hr

lemma triple_fix f x t1 H Q :
  H ==> Q (val_fix f x t1) →
  triple (trm_fix f x t1) H Q

lemma make_list_len (n : Int) (v : val) :
  (make_list n.natAbs v).length = n.natAbs

lemma findIdx_spec (arr : loc) (f : ℤ -> ℝ) (target : ℝ)
  (z n : ℤ) (_ : z <= n) (_ : 0 <= z) (N : ℕ) (_ : n <= N) :
  Set.InjOn f ⟦z, n⟧ ->
  target ∈ f '' ⟦z, n⟧ ->
  { arr(arr, i in N => f i) }
  [ findIdx arr target z n ]
  { v, ⌜ v = f.invFunOn ⟦z, n⟧ target ⌝ ∗ arr(arr, i in N => f i) }

lemma disjoint_update_not_r (h1 h2 : state) (x : loc) (v: val) :
  Finmap.Disjoint h1 h2 →
  x ∉ h2 →
  Finmap.Disjoint (Finmap.insert x v h1) h2

lemma read_state_frame :
  s.Disjoint h2 →
  p ∈ s →
  (fun v' s' ↦ v' = read_state p (s ∪ h2) ∧ s' = s ∪ h2 ) =
  (qstar (fun v' s' ↦ v' = read_state p s ∧ s' = s) (tohProp fun h ↦ h = h2))

lemma xsimpl_l_cancel_hwand_hstar_hempty :
  XSimp (Hla, Hlw, ((H2 -∗ H3) ∗ Hlt)) HR ->
  XSimp (Hla, (((emp ∗ H2) -∗ H3) ∗ Hlw), Hlt) HR

lemma union_same_keys (h₁ h₂ h₃ : state) :
  h₁.Disjoint h₃ → h₂.Disjoint h₃ →
  (h₁ ∪ h₃).keys = (h₂ ∪ h₃).keys →
  h₁.keys = h₂.keys
</all_available_lemmas>

<local_ctx>
import Lean

import Mathlib.Data.Finmap

import Mathlib.Algebra.Group.Basic

import Mathlib.Algebra.BigOperators.Group.Finset

import Mathlib.Algebra.BigOperators.Intervals

import Mathlib.Data.Int.Interval

import Mathlib.Order.Interval.Finset.Basic

import Batteries.Data.List.Perm

import Ssreflect.Lang

open Classical

abbrev loc := Nat

abbrev var := String

section Option.merge

variable {α : Type u} (f : α → α → α)

end Option.merge

abbrev Heap.heap (val : Type) := Finmap (λ _ : loc ↦ val)

class PartialCommMonoid (α : Type) extends AddCommSemigroup α where
  valid : α -> Prop
  valid_add : ∀ x, valid (x + y) -> valid x
  add_valid : ∀ x y, valid x -> valid y -> valid (x + y)

open PartialCommMonoid (valid)

section

variable {val : Type} [PartialCommMonoid val] -- [Inhabited val]

local notation "heap" => Heap.heap val

private def kmerge1 (l : loc) (v : val) (l₂ : List (Sigma (fun _ : loc => val))) : val :=
  match l₂.dlookup l with
  | .some v' => v + v'
  | _ => v

@[simp]
def kmerge : List (Sigma (fun _ : loc => val)) → List (Sigma (fun _ : loc => val)) → List (Sigma (fun _ : loc => val))
  | [], l₂ => l₂
  | s :: l₁, l₂ =>
    (if s.1 ∈ l₂.keys then
      ⟨s.1, kmerge1 s.1 s.2 l₂⟩ :: kmerge l₁ (l₂.kerase s.1)
    else s :: kmerge l₁ l₂)

noncomputable def AList.merge (h₁ h₂ : AList (fun _ : loc => val)) :  AList (fun _ : loc => val) :=
  ⟨kmerge h₁.entries h₂.entries, by admit /- proof elided -/
    ⟩

noncomputable def Heap.add (h₁ h₂ : heap) : heap :=
  Finmap.liftOn₂ h₁ h₂ (fun h₁ h₂ => (h₁.merge h₂).toFinmap) (by admit /- proof elided -/
    )

infixr:55 " +ʰ " => Heap.add

def validInter (h₁ h₂ : heap) : Prop :=
  ∀ l ∈ h₁, l ∈ h₂ -> ((h₁ +ʰ h₂).lookup l).any (valid (α := val))

infixr:55 " ⊥ʰ " => validInter
</local_ctx>

<target_theorem>
lemma validInter_assoc_r (h₁ h₂ h₃ : heap) :
  h₂ ⊥ʰ h₃ -> h₁ ⊥ʰ (h₂ +ʰ h₃) -> (h₁ +ʰ h₂) ⊥ʰ h₃ :=
</target_theorem>

