chore: adapt stdlib to new variable behavior

src/Init/Data/List/Erase.lean

@@ -354,7 +354,7 @@ theorem erase_eq_iff [LawfulBEq α] {a : α} {l : List α} :
   rw [erase_of_not_mem]
   simp_all
 
-theorem Nodup.erase_eq_filter [BEq α] [LawfulBEq α] {l} (d : Nodup l) (a : α) : l.erase a = l.filter (· != a) := by
+theorem Nodup.erase_eq_filter [LawfulBEq α] {l} (d : Nodup l) (a : α) : l.erase a = l.filter (· != a) := by
   induction d with
   | nil => rfl
   | cons m _n ih =>
@@ -367,13 +367,13 @@ theorem Nodup.erase_eq_filter [BEq α] [LawfulBEq α] {l} (d : Nodup l) (a : α)
       simpa [@eq_comm α] using m
     · simp [beq_false_of_ne h, ih, h]
 
-theorem Nodup.mem_erase_iff [BEq α] [LawfulBEq α] {a : α} (d : Nodup l) : a ∈ l.erase b ↔ a ≠ b ∧ a ∈ l := by
+theorem Nodup.mem_erase_iff [LawfulBEq α] {a : α} (d : Nodup l) : a ∈ l.erase b ↔ a ≠ b ∧ a ∈ l := by
   rw [Nodup.erase_eq_filter d, mem_filter, and_comm, bne_iff_ne]
 
-theorem Nodup.not_mem_erase [BEq α] [LawfulBEq α] {a : α} (h : Nodup l) : a ∉ l.erase a := fun H => by
+theorem Nodup.not_mem_erase [LawfulBEq α] {a : α} (h : Nodup l) : a ∉ l.erase a := fun H => by
   simpa using ((Nodup.mem_erase_iff h).mp H).left
 
-theorem Nodup.erase [BEq α] [LawfulBEq α] (a : α) : Nodup l → Nodup (l.erase a) :=
+theorem Nodup.erase [LawfulBEq α] (a : α) : Nodup l → Nodup (l.erase a) :=
   Nodup.sublist <| erase_sublist _ _
 
 end erase

src/Init/WF.lean

@@ -68,6 +68,7 @@ noncomputable def recursion {C : α → Sort v} (a : α) (h : ∀ x, (∀ y, r y
   induction (apply hwf a) with
   | intro x₁ _ ih => exact h x₁ ih
 
+include hwf in
 theorem induction {C : α → Prop} (a : α) (h : ∀ x, (∀ y, r y x → C y) → C x) : C a :=
   recursion hwf a h
 

src/Std/Data/DHashMap/Internal/RawLemmas.lean

@@ -20,7 +20,7 @@ open Std.DHashMap.Internal.List
 
 universe u v
 
-variable {α : Type u} {β : α → Type v} [BEq α] [Hashable α]
+variable {α : Type u} {β : α → Type v}
 
 namespace Std.DHashMap.Internal
 
@@ -41,6 +41,8 @@ theorem Raw.buckets_emptyc {i : Nat} {h} :
     (∅ : Raw α β).buckets[i]'h = AssocList.nil :=
   buckets_empty
 
+variable [BEq α] [Hashable α]
+
 @[simp]
 theorem buckets_empty {c} {i : Nat} {h} :
     (empty c : DHashMap α β).1.buckets[i]'h = AssocList.nil := by
@@ -55,7 +57,9 @@ end empty
 
 namespace Raw₀
 
+variable [BEq α] [Hashable α]
 variable (m : Raw₀ α β) (h : m.1.WF)
+set_option deprecated.oldSectionVars true
 
 /-- Internal implementation detail of the hash map -/
 scoped macro "wf_trivial" : tactic => `(tactic|

src/Std/Data/DHashMap/RawLemmas.lean

@@ -75,6 +75,7 @@ namespace Raw
 open Internal.Raw₀ Internal.Raw
 
 variable {m : Raw α β} (h : m.WF)
+set_option deprecated.oldSectionVars true
 
 @[simp]
 theorem isEmpty_empty {c} : (empty c : Raw α β).isEmpty := by

src/Std/Data/HashMap/RawLemmas.lean

@@ -27,6 +27,7 @@ namespace Std.HashMap
 namespace Raw
 
 variable {m : Raw α β} (h : m.WF)
+set_option deprecated.oldSectionVars true
 
 private theorem ext {m m' : Raw α β} : m.inner = m'.inner → m = m' := by
   cases m; cases m'; rintro rfl; rfl

src/Std/Data/HashSet/Lemmas.lean

@@ -20,7 +20,7 @@ set_option autoImplicit false
 
 universe u v
 
-variable {α : Type u} {_ : BEq α} {_ : Hashable α} [EquivBEq α] [LawfulHashable α]
+variable {α : Type u} {_ : BEq α} {_ : Hashable α}
 
 namespace Std.HashSet
 

src/Std/Data/HashSet/RawLemmas.lean

@@ -27,6 +27,7 @@ namespace Std.HashSet
 namespace Raw
 
 variable {m : Raw α} (h : m.WF)
+set_option deprecated.oldSectionVars true
 
 private theorem ext {m m' : Raw α} : m.inner = m'.inner → m = m' := by
   cases m; cases m'; rintro rfl; rfl