Theorem: Batteries.HashMap.Imp.insert_WF
File: .lake/packages/batteries/Batteries/Data/HashMap/WF.lean

Proof steps:
state_before: α : Type u_1
β : Type u_2
inst✝¹ : BEq α
inst✝ : Hashable α
m : Imp α β
k : α
v : β
h : m.buckets.WF
⊢ (m.insert k v).buckets.WF
state_after: α : Type u_1
β : Type u_2
inst✝¹ : BEq α
inst✝ : Hashable α
m : Imp α β
k : α
v : β
h : m.buckets.WF
⊢ (match AssocList.contains k m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat] with
      | true =>
        { size := m.size,
          buckets :=
            m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
              (AssocList.replace k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯ }
      | false =>
        if numBucketsForCapacity (m.size + 1) ≤ m.buckets.val.size then
          { size := m.size + 1,
            buckets :=
              m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
                (AssocList.cons k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯ }
        else
          expand (m.size + 1)
            (m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
              (AssocList.cons k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯)).buckets.WF
tactic: dsimp [insert, cond]
state_before: α : Type u_1
β : Type u_2
inst✝¹ : BEq α
inst✝ : Hashable α
m : Imp α β
k : α
v : β
h : m.buckets.WF
⊢ (match AssocList.contains k m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat] with
      | true =>
        { size := m.size,
          buckets :=
            m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
              (AssocList.replace k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯ }
      | false =>
        if numBucketsForCapacity (m.size + 1) ≤ m.buckets.val.size then
          { size := m.size + 1,
            buckets :=
              m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
                (AssocList.cons k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯ }
        else
          expand (m.size + 1)
            (m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
              (AssocList.cons k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯)).buckets.WF
state_after: case h_1
α : Type u_1
β : Type u_2
inst✝¹ : BEq α
inst✝ : Hashable α
m : Imp α β
k : α
v : β
h : m.buckets.WF
c✝ : Bool
heq✝ : AssocList.contains k m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat] = true
⊢ { size := m.size,
        buckets :=
          m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
            (AssocList.replace k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯ }.buckets.WF

case h_2
α : Type u_1
β : Type u_2
inst✝¹ : BEq α
inst✝ : Hashable α
m : Imp α β
k : α
v : β
h : m.buckets.WF
c✝ : Bool
heq✝ : AssocList.contains k m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat] = false
⊢ (if numBucketsForCapacity (m.size + 1) ≤ m.buckets.val.size then
        { size := m.size + 1,
          buckets :=
            m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
              (AssocList.cons k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯ }
      else
        expand (m.size + 1)
          (m.buckets.update (mkIdx ⋯ (hash k).toUSize).val
            (AssocList.cons k v m.buckets.val[(mkIdx ⋯ (hash k).toUSize).val.toNat]) ⋯)).buckets.WF
tactic: split