diff options
author | Son Ho | 2023-12-23 00:16:53 +0100 |
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committer | Son Ho | 2023-12-23 00:16:53 +0100 |
commit | 091f9f0f49db3c581a33d29470323ab417744845 (patch) | |
tree | d8ddc513dc5c4ca3d94640bdb765fd437836f60f /tests | |
parent | a0c58326c43a7a8026b3d4c158017bf126180e90 (diff) |
Update the proof of the hashmap in Lean
Diffstat (limited to '')
-rw-r--r-- | tests/lean/Hashmap/Properties.lean | 144 |
1 files changed, 44 insertions, 100 deletions
diff --git a/tests/lean/Hashmap/Properties.lean b/tests/lean/Hashmap/Properties.lean index e79c422d..7215e286 100644 --- a/tests/lean/Hashmap/Properties.lean +++ b/tests/lean/Hashmap/Properties.lean @@ -55,71 +55,6 @@ theorem match_lawful_beq [BEq α] [LawfulBEq α] [DecidableEq α] (x y : α) : (x == y) = (if x = y then true else false) := by split <;> simp_all -@[pspec] -theorem insert_in_list_spec0 {α : Type} (key: Usize) (value: α) (ls: List α) : - ∃ b, - insert_in_list α key value ls = ret b ∧ - (b ↔ ls.lookup key = none) - := match ls with - | .Nil => by simp [insert_in_list, insert_in_list_loop] - | .Cons k v tl => - if h: k = key then -- TODO: The order of k/key matters - by - simp [insert_in_list] - rw [insert_in_list_loop] - simp [h] - else - have ⟨ b, hi ⟩ := insert_in_list_spec0 key value tl - by - exists b - simp [insert_in_list] - rw [insert_in_list_loop] -- TODO: Using simp leads to infinite recursion - simp only [insert_in_list] at hi - simp [*] - --- Variation: use progress -theorem insert_in_list_spec1 {α : Type} (key: Usize) (value: α) (ls: List α) : - ∃ b, - insert_in_list α key value ls = ret b ∧ - (b ↔ ls.lookup key = none) - := match ls with - | .Nil => by simp [insert_in_list, insert_in_list_loop] - | .Cons k v tl => - if h: k = key then -- TODO: The order of k/key matters - by - simp [insert_in_list] - rw [insert_in_list_loop] - simp [h] - else - by - simp only [insert_in_list] - rw [insert_in_list_loop] - conv => rhs; ext; simp [*] - progress keep heq as ⟨ b, hi ⟩ - simp only [insert_in_list] at heq - exists b - --- Variation: use tactics from the beginning -theorem insert_in_list_spec2 {α : Type} (key: Usize) (value: α) (ls: List α) : - ∃ b, - insert_in_list α key value ls = ret b ∧ - (b ↔ (ls.lookup key = none)) - := by - induction ls - case Nil => simp [insert_in_list, insert_in_list_loop] - case Cons k v tl ih => - simp only [insert_in_list] - rw [insert_in_list_loop] - simp only - if h: k = key then - simp [h] - else - conv => rhs; ext; left; simp [h] -- TODO: Simplify - simp only [insert_in_list] at ih; - -- TODO: give the possibility of using underscores - progress as ⟨ b, h ⟩ - simp [*] - def distinct_keys (ls : Core.List (Usize × α)) := ls.pairwise_rel (λ x y => x.fst ≠ y.fst) def hash_mod_key (k : Usize) (l : Int) : Int := @@ -175,11 +110,16 @@ def inv (hm : HashMap α) : Prop := base_inv hm -- TODO: either the hashmap is not overloaded, or we can't resize it -theorem insert_in_list_back_spec_aux {α : Type} (l : Int) (key: Usize) (value: α) (l0: List α) +-- This rewriting lemma is problematic below +attribute [-simp] Bool.exists_bool + +theorem insert_in_list_spec_aux {α : Type} (l : Int) (key: Usize) (value: α) (l0: List α) (hinv : slot_s_inv_hash l (hash_mod_key key l) l0.v) (hdk : distinct_keys l0.v) : - ∃ l1, - insert_in_list_back α key value l0 = ret l1 ∧ + ∃ b l1, + insert_in_list α key value l0 = ret (b, l1) ∧ + -- The boolean is true ↔ we inserted a new binding + (b ↔ (l0.lookup key = none)) ∧ -- We update the binding l1.lookup key = value ∧ (∀ k, k ≠ key → l1.lookup k = l0.lookup k) ∧ @@ -193,16 +133,19 @@ theorem insert_in_list_back_spec_aux {α : Type} (l : Int) (key: Usize) (value: distinct_keys l1.v ∧ -- We need this auxiliary property to prove that the keys distinct properties is preserved (∀ k, k ≠ key → l0.v.allP (λ (k1, _) => k ≠ k1) → l1.v.allP (λ (k1, _) => k ≠ k1)) - := match l0 with - | .Nil => by checkpoint + := + match l0 with + | .Nil => by + exists true -- TODO: why do we need to do this? simp (config := {contextual := true}) - [insert_in_list_back, insert_in_list_loop_back, + [insert_in_list, insert_in_list_loop, List.v, slot_s_inv_hash, distinct_keys, List.pairwise_rel] | .Cons k v tl0 => - if h: k = key then by checkpoint - simp [insert_in_list_back] - rw [insert_in_list_loop_back] + if h: k = key then by + rw [insert_in_list] + rw [insert_in_list_loop] simp [h] + exists false; simp -- TODO: why do we need to do this? split_conjs . intros; simp [*] . simp [List.v, slot_s_inv_hash] at * @@ -210,17 +153,17 @@ theorem insert_in_list_back_spec_aux {α : Type} (l : Int) (key: Usize) (value: . simp [*, distinct_keys] at * apply hdk . tauto - else by checkpoint - simp [insert_in_list_back] - rw [insert_in_list_loop_back] + else by + rw [insert_in_list] + rw [insert_in_list_loop] simp [h] have : slot_s_inv_hash l (hash_mod_key key l) (List.v tl0) := by checkpoint simp_all [List.v, slot_s_inv_hash] have : distinct_keys (List.v tl0) := by checkpoint simp [distinct_keys] at hdk simp [hdk, distinct_keys] - progress keep heq as ⟨ tl1 .. ⟩ - simp only [insert_in_list_back] at heq + progress keep heq as ⟨ b, tl1 .. ⟩ + simp only [insert_in_list] at heq have : slot_s_inv_hash l (hash_mod_key key l) (List.v (List.Cons k v tl1)) := by checkpoint simp [List.v, slot_s_inv_hash] at * simp [*] @@ -228,14 +171,16 @@ theorem insert_in_list_back_spec_aux {α : Type} (l : Int) (key: Usize) (value: simp [distinct_keys] at * simp [*] -- TODO: canonize addition by default? + exists b simp_all [Int.add_assoc, Int.add_comm, Int.add_left_comm] @[pspec] -theorem insert_in_list_back_spec {α : Type} (l : Int) (key: Usize) (value: α) (l0: List α) +theorem insert_in_list_spec {α : Type} (l : Int) (key: Usize) (value: α) (l0: List α) (hinv : slot_s_inv_hash l (hash_mod_key key l) l0.v) (hdk : distinct_keys l0.v) : - ∃ l1, - insert_in_list_back α key value l0 = ret l1 ∧ + ∃ b l1, + insert_in_list α key value l0 = ret (b, l1) ∧ + (b ↔ (l0.lookup key = none)) ∧ -- We update the binding l1.lookup key = value ∧ (∀ k, k ≠ key → l1.lookup k = l0.lookup k) ∧ @@ -248,7 +193,8 @@ theorem insert_in_list_back_spec {α : Type} (l : Int) (key: Usize) (value: α) -- The keys are distinct distinct_keys l1.v := by - progress with insert_in_list_back_spec_aux as ⟨ l1 .. ⟩ + progress with insert_in_list_spec_aux as ⟨ b, l1 .. ⟩ + exists b exists l1 @[simp] @@ -286,7 +232,7 @@ set_option pp.coercions false -- do not print coercions with ↑ (this doesn't p -- The proof below is a bit expensive, so we need to increase the maximum number -- of heart beats -set_option maxHeartbeats 400000 +set_option maxHeartbeats 1000000 theorem insert_no_resize_spec {α : Type} (hm : HashMap α) (key : Usize) (value : α) (hinv : hm.inv) (hnsat : hm.lookup key = none → hm.len_s < Usize.max) : @@ -315,9 +261,19 @@ theorem insert_no_resize_spec {α : Type} (hm : HashMap α) (key : Usize) (value simp [hinv] -- TODO: we want to automate that simp [*, Int.emod_lt_of_pos] - progress as ⟨ l, h_leq ⟩ - -- TODO: make progress use the names written in the goal - progress as ⟨ inserted ⟩ + progress as ⟨ l, index_mut_back, h_leq, h_index_mut_back ⟩ + simp [h_index_mut_back] at *; clear h_index_mut_back index_mut_back + have h_slot : + slot_s_inv_hash hm.slots.length (hash_mod_key key hm.slots.length) l.v := by + simp [inv] at hinv + have h := (hinv.right.left hash_mod.val (by assumption) (by assumption)).right + simp [slot_t_inv, hhm] at h + simp [h, hhm, h_leq] + have hd : distinct_keys l.v := by + simp [inv, slots_t_inv, slot_t_inv] at hinv + have h := hinv.right.left hash_mod.val (by assumption) (by assumption) + simp [h, h_leq] + progress as ⟨ inserted, l0, _, _, _, _, hlen .. ⟩ rw [if_update_eq] -- TODO: necessary because we don't have a join -- TODO: progress to ... have hipost : @@ -336,20 +292,9 @@ theorem insert_no_resize_spec {α : Type} (hm : HashMap α) (key : Usize) (value else simp [*, Pure.pure] progress as ⟨ i0 ⟩ - have h_slot : slot_s_inv_hash hm.slots.length (hash_mod_key key hm.slots.length) l.v - := by - simp [inv] at hinv - have h := (hinv.right.left hash_mod.val (by assumption) (by assumption)).right - simp [slot_t_inv, hhm] at h - simp [h, hhm, h_leq] - have hd : distinct_keys l.v := by checkpoint - simp [inv, slots_t_inv, slot_t_inv] at hinv - have h := hinv.right.left hash_mod.val (by assumption) (by assumption) - simp [h, h_leq] -- TODO: hide the variables and only keep the props -- TODO: allow providing terms to progress to instantiate the meta variables -- which are not propositions - progress as ⟨ l0, _, _, _, hlen .. ⟩ progress keep hv as ⟨ v, h_veq ⟩ -- TODO: update progress to automate that -- TODO: later I don't want to inline nhm - we need to control simp: deactivate @@ -428,8 +373,7 @@ theorem insert_no_resize_spec {α : Type} (hm : HashMap α) (key : Usize) (value simp [*] else simp [*] - . -- TODO: simp[*] fails: "(deterministic) timeout at 'whnf'" - simp [hinv, h_veq, nhm_eq] + . simp [hinv, h_veq, nhm_eq] simp_all end HashMap |