[Merged by Bors] - chore: bump toolchain to v4.16.0-rc1, and merge bump/v4.16.0

Archive/Imo/Imo2024Q5.lean

@@ -302,7 +302,7 @@ lemma Path.tail_induction {motive : Path N → Prop} (ind : ∀ p, motive p.tail
   case cons head tail hi =>
     by_cases h : (p'.cells[1]'p'.one_lt_length_cells).1 = 0
     · refine ind p' ?_
-      simp_rw [Path.tail, if_pos h, List.tail_cons]
+      simp_rw [Path.tail, if_pos h, p', List.tail_cons]
       exact hi _ _ _ _
     · exact base p' h
 

Mathlib.lean

@@ -4841,7 +4841,6 @@ import Mathlib.Tactic.DefEqTransformations
 import Mathlib.Tactic.DeprecateTo
 import Mathlib.Tactic.DeriveCountable
 import Mathlib.Tactic.DeriveFintype
-import Mathlib.Tactic.DeriveToExpr
 import Mathlib.Tactic.DeriveTraversable
 import Mathlib.Tactic.Eqns
 import Mathlib.Tactic.Eval

Mathlib/Algebra/BigOperators/Fin.lean

@@ -162,7 +162,7 @@ theorem prod_Ioi_succ {M : Type*} [CommMonoid M] {n : ℕ} (i : Fin n) (v : Fin
 
 @[to_additive]
 theorem prod_congr' {M : Type*} [CommMonoid M] {a b : ℕ} (f : Fin b → M) (h : a = b) :
-    (∏ i : Fin a, f (cast h i)) = ∏ i : Fin b, f i := by
+    (∏ i : Fin a, f (i.cast h)) = ∏ i : Fin b, f i := by
   subst h
   congr
 

Mathlib/Algebra/BigOperators/Group/List.lean

@@ -5,7 +5,6 @@ Authors: Johannes Hölzl, Floris van Doorn, Sébastien Gouëzel, Alex J. Best
 -/
 import Mathlib.Algebra.Divisibility.Basic
 import Mathlib.Algebra.Group.Int
-import Mathlib.Data.List.Lemmas
 import Mathlib.Data.List.Dedup
 import Mathlib.Data.List.Flatten
 import Mathlib.Data.List.Pairwise
@@ -637,10 +636,6 @@ end MonoidHom
 
 end MonoidHom
 
-set_option linter.deprecated false in
-@[simp, deprecated "No deprecation message was provided." (since := "2024-10-17")]
-lemma Nat.sum_eq_listSum (l : List ℕ) : Nat.sum l = l.sum := rfl
-
 namespace List
 
 lemma length_sigma {σ : α → Type*} (l₁ : List α) (l₂ : ∀ a, List (σ a)) :

Mathlib/Algebra/MvPolynomial/SchwartzZippel.lean

@@ -146,7 +146,7 @@ lemma schwartz_zippel_sup_sum :
         calc
           #{x₀ ∈ S 0 | eval (cons x₀ xₜ) p = 0} ≤ #pₓ.roots.toFinset := by
             gcongr
-            simp (config := { contextual := true }) [subset_iff, eval_eq_eval_mv_eval', pₓ, hpₓ₀]
+            simp +contextual [subset_iff, eval_eq_eval_mv_eval', pₓ, hpₓ₀, p']
           _ ≤ Multiset.card pₓ.roots := pₓ.roots.toFinset_card_le
           _ ≤ pₓ.natDegree := pₓ.card_roots'
           _ = k := hpₓdeg

Mathlib/AlgebraicGeometry/EllipticCurve/NormalForms.lean

@@ -425,7 +425,8 @@ theorem toCharThreeNF_spec_of_b₂_ne_zero (hb₂ : W.b₂ ≠ 0) :
   constructor
   · simp
   · simp
-  · field_simp [W.toShortNFOfCharThree_a₂ ▸ hb₂]
+  · have ha₂ : W'.a₂ ≠ 0 := W.toShortNFOfCharThree_a₂ ▸ hb₂
+    field_simp [ha₂]
     linear_combination (W'.a₄ * W'.a₂ ^ 2 + W'.a₄ ^ 2) * CharP.cast_eq_zero F 3
 
 theorem toCharThreeNF_spec_of_b₂_eq_zero (hb₂ : W.b₂ = 0) :

Mathlib/Analysis/Calculus/ContDiff/FaaDiBruno.lean

@@ -401,10 +401,10 @@ def extendMiddle (c : OrderedFinpartition n) (k : Fin c.length) : OrderedFinpart
       rcases eq_or_ne (c.index i) k with rfl | hi
       · have A : update c.partSize (c.index i) (c.partSize (c.index i) + 1) (c.index i) =
           c.partSize (c.index i) + 1 := by simp
-        exact ⟨c.index i, cast A.symm (succ (c.invEmbedding i)), by simp⟩
+        exact ⟨c.index i, (succ (c.invEmbedding i)).cast A.symm , by simp⟩
       · have A : update c.partSize k (c.partSize k + 1) (c.index i) = c.partSize (c.index i) := by
           simp [hi]
-        exact ⟨c.index i, cast A.symm (c.invEmbedding i), by simp [hi]⟩
+        exact ⟨c.index i, (c.invEmbedding i).cast A.symm, by simp [hi]⟩
 
 lemma index_extendMiddle_zero (c : OrderedFinpartition n) (i : Fin c.length) :
     (c.extendMiddle i).index 0 = i := by
@@ -678,8 +678,8 @@ def extendEquiv (n : ℕ) :
           · simp only [↓reduceDIte, comp_apply]
             rcases eq_or_ne j 0 with rfl | hj
             · simpa using c.emb_zero
-            · let j' := Fin.pred (cast B.symm j) (by simpa using hj)
-              have : j = cast B (succ j') := by simp [j']
+            · let j' := Fin.pred (j.cast B.symm) (by simpa using hj)
+              have : j = (succ j').cast B := by simp [j']
               simp only [this, coe_cast, val_succ, cast_mk, cases_succ', comp_apply, succ_mk,
                 Nat.succ_eq_add_one, succ_pred]
               rfl

Mathlib/Analysis/Convex/Continuous.lean

@@ -51,7 +51,8 @@ lemma ConvexOn.lipschitzOnWith_of_abs_le (hf : ConvexOn ℝ (ball x₀ r) f) (h
       ε * (f x - f y) ≤ ‖x - y‖ * (f z - f x) := by
         rw [mul_sub, mul_sub, sub_le_sub_iff, ← add_mul]
         have h := hf.2 hy' hz (by positivity) (by positivity) hab
-        field_simp [← hxyz, a, b, ← mul_div_right_comm] at h
+        rw [← hxyz] at h
+        field_simp [a, b, ← mul_div_right_comm] at h
         rwa [← le_div_iff₀' (by positivity), add_comm (_ * _)]
       _ ≤ _ := by
         rw [sub_eq_add_neg (f _), two_mul]

Mathlib/CategoryTheory/Galois/Decomposition.lean

@@ -154,12 +154,14 @@ lemma connected_component_unique {X A B : C} [IsConnected A] [IsConnected B] (a
   have : IsIso v := IsConnected.noTrivialComponent Y v hn
   use (asIso u).symm ≪≫ asIso v
   have hu : G.map u y = a := by
-    simp only [y, e, ← PreservesPullback.iso_hom_fst G, fiberPullbackEquiv, Iso.toEquiv_comp,
-      Equiv.symm_trans_apply, Iso.toEquiv_symm_fun, types_comp_apply, inv_hom_id_apply]
+    simp only [u, G, y, e, ← PreservesPullback.iso_hom_fst G, fiberPullbackEquiv,
+      Iso.toEquiv_comp, Equiv.symm_trans_apply, Iso.toEquiv_symm_fun, types_comp_apply,
+      inv_hom_id_apply]
     erw [Types.pullbackIsoPullback_inv_fst_apply (F.map i) (F.map j)]
   have hv : G.map v y = b := by
-    simp only [y, e, ← PreservesPullback.iso_hom_snd G, fiberPullbackEquiv, Iso.toEquiv_comp,
-      Equiv.symm_trans_apply, Iso.toEquiv_symm_fun, types_comp_apply, inv_hom_id_apply]
+    simp only [v, G, y, e, ← PreservesPullback.iso_hom_snd G, fiberPullbackEquiv,
+      Iso.toEquiv_comp, Equiv.symm_trans_apply, Iso.toEquiv_symm_fun, types_comp_apply,
+      inv_hom_id_apply]
     erw [Types.pullbackIsoPullback_inv_snd_apply (F.map i) (F.map j)]
   rw [← hu, ← hv]
   show (F.toPrefunctor.map u ≫ F.toPrefunctor.map _) y = F.toPrefunctor.map v y

Mathlib/Computability/TMToPartrec.lean

@@ -1238,7 +1238,7 @@ theorem move_ok {p k₁ k₂ q s L₁ o L₂} {S : K' → List Γ'} (h₁ : k₁
     swap
     · rw [Function.update_of_ne h₁.symm, List.reverseAux_nil]
     refine TransGen.head' rfl ?_
-    simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim, ne_eq]
+    rw [tr]; simp only [pop', TM2.stepAux]
     revert e; cases' S k₁ with a Sk <;> intro e
     · cases e
       rfl
@@ -1248,7 +1248,7 @@ theorem move_ok {p k₁ k₂ q s L₁ o L₂} {S : K' → List Γ'} (h₁ : k₁
     simp only [e]
     rfl
   · refine TransGen.head rfl ?_
-    simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim, ne_eq, List.reverseAux_cons]
+    rw [tr]; simp only [pop', Option.elim, TM2.stepAux, push']
     cases' e₁ : S k₁ with a' Sk <;> rw [e₁, splitAtPred] at e
     · cases e
     cases e₂ : p a' <;> simp only [e₂, cond] at e
@@ -1273,16 +1273,15 @@ theorem move₂_ok {p k₁ k₂ q s L₁ o L₂} {S : K' → List Γ'} (h₁ : k
       ⟨some q, none, update (update S k₁ (o.elim id List.cons L₂)) k₂ (L₁ ++ S k₂)⟩ := by
   refine (move_ok h₁.1 e).trans (TransGen.head rfl ?_)
   simp only [TM2.step, Option.mem_def, TM2.stepAux, id_eq, ne_eq, Option.elim]
-  cases o <;> simp only [Option.elim, id]
-  · simp only [TM2.stepAux, Option.isSome, cond_false]
-    convert move_ok h₁.2.1.symm (splitAtPred_false _) using 2
+  cases o <;> simp only [Option.elim] <;> rw [tr]
+    <;> simp only [id, TM2.stepAux, Option.isSome, cond_true, cond_false]
+  · convert move_ok h₁.2.1.symm (splitAtPred_false _) using 2
     simp only [Function.update_comm h₁.1, Function.update_idem]
     rw [show update S rev [] = S by rw [← h₂, Function.update_eq_self]]
     simp only [Function.update_of_ne h₁.2.2.symm, Function.update_of_ne h₁.2.1,
       Function.update_of_ne h₁.1.symm, List.reverseAux_eq, h₂, Function.update_self,
       List.append_nil, List.reverse_reverse]
-  · simp only [TM2.stepAux, Option.isSome, cond_true]
-    convert move_ok h₁.2.1.symm (splitAtPred_false _) using 2
+  · convert move_ok h₁.2.1.symm (splitAtPred_false _) using 2
     simp only [h₂, Function.update_comm h₁.1, List.reverseAux_eq, Function.update_self,
       List.append_nil, Function.update_idem]
     rw [show update S rev [] = S by rw [← h₂, Function.update_eq_self]]
@@ -1293,7 +1292,7 @@ theorem clear_ok {p k q s L₁ o L₂} {S : K' → List Γ'} (e : splitAtPred p
     Reaches₁ (TM2.step tr) ⟨some (Λ'.clear p k q), s, S⟩ ⟨some q, o, update S k L₂⟩ := by
   induction' L₁ with a L₁ IH generalizing S s
   · refine TransGen.head' rfl ?_
-    simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim]
+    rw [tr]; simp only [pop', TM2.step, Option.mem_def, TM2.stepAux, Option.elim]
     revert e; cases' S k with a Sk <;> intro e
     · cases e
       rfl
@@ -1303,7 +1302,7 @@ theorem clear_ok {p k q s L₁ o L₂} {S : K' → List Γ'} (e : splitAtPred p
     rcases e with ⟨e₁, e₂⟩
     rw [e₁, e₂]
   · refine TransGen.head rfl ?_
-    simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim]
+    rw [tr]; simp only [pop', TM2.step, Option.mem_def, TM2.stepAux, Option.elim]
     cases' e₁ : S k with a' Sk <;> rw [e₁, splitAtPred] at e
     · cases e
     cases e₂ : p a' <;> simp only [e₂, cond] at e
@@ -1322,9 +1321,10 @@ theorem copy_ok (q s a b c d) :
   · refine TransGen.single ?_
     simp
   refine TransGen.head rfl ?_
+  rw [tr]
   simp only [TM2.step, Option.mem_def, TM2.stepAux, elim_rev, List.head?_cons, Option.isSome_some,
     List.tail_cons, elim_update_rev, ne_eq, Function.update_of_ne, elim_main, elim_update_main,
-    elim_stack, elim_update_stack, cond_true, List.reverseAux_cons]
+    elim_stack, elim_update_stack, cond_true, List.reverseAux_cons, pop', push']
   exact IH _ _ _
 
 theorem trPosNum_natEnd : ∀ (n), ∀ x ∈ trPosNum n, natEnd x = false
@@ -1358,6 +1358,7 @@ theorem head_main_ok {q s L} {c d : List Γ'} :
           (splitAtPred_eq _ _ (trNat L.headI) o (trList L.tail) (trNat_natEnd _) ?_)).trans
       (TransGen.head rfl (TransGen.head rfl ?_))
   · cases L <;> simp [o]
+  rw [tr]
   simp only [TM2.step, Option.mem_def, TM2.stepAux, elim_update_main, elim_rev, elim_update_rev,
     Function.update_self, trList]
   rw [if_neg (show o ≠ some Γ'.consₗ by cases L <;> simp [o])]
@@ -1375,6 +1376,7 @@ theorem head_stack_ok {q s L₁ L₂ L₃} :
         (move_ok (by decide)
           (splitAtPred_eq _ _ [] (some Γ'.consₗ) L₃ (by rintro _ ⟨⟩) ⟨rfl, rfl⟩))
         (TransGen.head rfl (TransGen.head rfl ?_))
+    rw [tr]
     simp only [TM2.step, Option.mem_def, TM2.stepAux, ite_true, id_eq, trList, List.nil_append,
       elim_update_stack, elim_rev, List.reverseAux_nil, elim_update_rev, Function.update_self,
       List.headI_nil, trNat_default]
@@ -1428,7 +1430,8 @@ theorem succ_ok {q s n} {c d : List Γ'} :
     simp [PosNum.succ, trPosNum]
     rfl
   · refine ⟨l₁, _, some Γ'.bit0, rfl, TransGen.single ?_⟩
-    simp only [TM2.step, TM2.stepAux, elim_main, elim_update_main, ne_eq, Function.update_of_ne,
+    simp only [TM2.step]; rw [tr]
+    simp only [TM2.stepAux, pop', elim_main, elim_update_main, ne_eq, Function.update_of_ne,
       elim_rev, elim_update_rev, Function.update_self, Option.mem_def, Option.some.injEq]
     rfl
 
@@ -1445,11 +1448,9 @@ theorem pred_ok (q₁ q₂ s v) (c d : List Γ') : ∃ s',
   simp only [TM2.step, trList, trNat.eq_1, trNum, Nat.cast_succ, Num.add_one, Num.succ,
     List.tail_cons, List.headI_cons]
   cases' (n : Num) with a
-  · simp only [trPosNum, List.singleton_append, List.nil_append]
+  · simp only [trPosNum, Num.succ', List.singleton_append, List.nil_append]
     refine TransGen.head rfl ?_
-    simp only [Option.mem_def, TM2.stepAux, elim_main, List.head?_cons, Option.some.injEq,
-      decide_false, List.tail_cons, elim_update_main, ne_eq, Function.update_of_ne, elim_rev,
-      elim_update_rev, natEnd, Function.update_self,  cond_true, cond_false]
+    rw [tr]; simp only [pop', TM2.stepAux, cond_false]
     convert unrev_ok using 2
     simp
   simp only [Num.succ']
@@ -1555,13 +1556,11 @@ theorem tr_ret_respects (k v s) : ∃ b₂,
     by_cases h : v.headI = 0 <;> simp only [h, ite_true, ite_false] at this ⊢
     · obtain ⟨c, h₁, h₂⟩ := IH v.tail (trList v).head?
       refine ⟨c, h₁, TransGen.head rfl ?_⟩
-      simp only [Option.mem_def, TM2.stepAux, trContStack, contStack, elim_main, this, cond_true,
-        elim_update_main]
+      rw [trCont, tr]; simp only [pop', TM2.stepAux, elim_main, this, elim_update_main]
       exact h₂
     · obtain ⟨s', h₁, h₂⟩ := trNormal_respects f (Cont.fix f k) v.tail (some Γ'.cons)
       refine ⟨_, h₁, TransGen.head rfl <| TransGen.trans ?_ h₂⟩
-      simp only [Option.mem_def, TM2.stepAux, elim_main, this.1, cond_false, elim_update_main,
-        trCont]
+      rw [trCont, tr]; simp only [pop', TM2.stepAux, elim_main, this.1]
       convert clear_ok (splitAtPred_eq _ _ (trNat v.headI).tail (some Γ'.cons) _ _ _) using 2
       · simp
         convert rfl

Mathlib/Computability/TuringMachine.lean

@@ -1828,12 +1828,12 @@ theorem tr_respects : Respects (TM0.step M) (TM1.step (tr M)) fun a b ↦ trCfg
       cases' s with d a <;> rfl
     intro e
     refine TransGen.head ?_ (TransGen.head' this ?_)
-    · simp only [TM1.step, TM1.stepAux]
+    · simp only [TM1.step, TM1.stepAux, tr]
       rw [e]
       rfl
     cases e' : M q' _
     · apply ReflTransGen.single
-      simp only [TM1.step, TM1.stepAux]
+      simp only [TM1.step, TM1.stepAux, tr]
       rw [e']
       rfl
     · rfl
@@ -1926,7 +1926,6 @@ section
 variable [DecidableEq K]
 
 /-- The step function for the TM2 model. -/
-@[simp]
 def stepAux : Stmt₂ → σ → (∀ k, List (Γ k)) → Cfg₂
   | push k f q, v, S => stepAux q v (update S k (f v :: S k))
   | peek k f q, v, S => stepAux q (f v (S k).head?) S
@@ -1937,11 +1936,13 @@ def stepAux : Stmt₂ → σ → (∀ k, List (Γ k)) → Cfg₂
   | halt, v, S => ⟨none, v, S⟩
 
 /-- The step function for the TM2 model. -/
-@[simp]
 def step (M : Λ → Stmt₂) : Cfg₂ → Option Cfg₂
   | ⟨none, _, _⟩ => none
   | ⟨some l, v, S⟩ => some (stepAux (M l) v S)
 
+attribute [simp] stepAux.eq_1 stepAux.eq_2 stepAux.eq_3
+  stepAux.eq_4 stepAux.eq_5 stepAux.eq_6 stepAux.eq_7 step.eq_1 step.eq_2
+
 /-- The (reflexive) reachability relation for the TM2 model. -/
 def Reaches (M : Λ → Stmt₂) : Cfg₂ → Cfg₂ → Prop :=
   ReflTransGen fun a b ↦ b ∈ step M a
@@ -2292,7 +2293,7 @@ noncomputable def trStmts₁ : Stmt₂ → Finset Λ'₂₁
 
 theorem trStmts₁_run {k : K} {s : StAct₂ k} {q : Stmt₂} :
     trStmts₁ (stRun s q) = {go k s q, ret q} ∪ trStmts₁ q := by
-  cases s <;> simp only [trStmts₁]
+  cases s <;> simp only [trStmts₁, stRun]
 
 theorem tr_respects_aux₂ [DecidableEq K] {k : K} {q : Stmt₂₁} {v : σ} {S : ∀ k, List (Γ k)}
     {L : ListBlank (∀ k, Option (Γ k))}

Mathlib/Data/Fin/Basic.lean

@@ -269,7 +269,7 @@ This one instead uses a `NeZero n` typeclass hypothesis.
 theorem pos_iff_ne_zero' [NeZero n] (a : Fin n) : 0 < a ↔ a ≠ 0 := by
   rw [← val_fin_lt, val_zero', Nat.pos_iff_ne_zero, Ne, Ne, Fin.ext_iff, val_zero']
 
-@[simp] lemma cast_eq_self (a : Fin n) : cast rfl a = a := rfl
+@[simp] lemma cast_eq_self (a : Fin n) : a.cast rfl = a := rfl
 
 @[simp] theorem cast_eq_zero {k l : ℕ} [NeZero k] [NeZero l]
     (h : k = l) (x : Fin k) : Fin.cast h x = 0 ↔ x = 0 := by simp [← val_eq_val]
@@ -299,7 +299,7 @@ theorem revPerm_symm : (@revPerm n).symm = revPerm :=
   rfl
 
 theorem cast_rev (i : Fin n) (h : n = m) :
-    cast h i.rev = (i.cast h).rev := by
+    i.rev.cast h = (i.cast h).rev := by
   subst h; simp
 
 theorem rev_eq_iff {i j : Fin n} : rev i = j ↔ i = rev j := by
@@ -619,23 +619,23 @@ theorem coe_of_injective_castLE_symm {n k : ℕ} (h : n ≤ k) (i : Fin k) (hi)
   rw [← coe_castLE h]
   exact congr_arg Fin.val (Equiv.apply_ofInjective_symm _ _)
 
-theorem leftInverse_cast (eq : n = m) : LeftInverse (cast eq.symm) (cast eq) :=
+theorem leftInverse_cast (eq : n = m) : LeftInverse (Fin.cast eq.symm) (Fin.cast eq) :=
   fun _ => rfl
 
-theorem rightInverse_cast (eq : n = m) : RightInverse (cast eq.symm) (cast eq) :=
+theorem rightInverse_cast (eq : n = m) : RightInverse (Fin.cast eq.symm) (Fin.cast eq) :=
   fun _ => rfl
 
-theorem cast_lt_cast (eq : n = m) {a b : Fin n} : cast eq a < cast eq b ↔ a < b :=
+theorem cast_lt_cast (eq : n = m) {a b : Fin n} : a.cast eq < b.cast eq ↔ a < b :=
   Iff.rfl
 
-theorem cast_le_cast (eq : n = m) {a b : Fin n} : cast eq a ≤ cast eq b ↔ a ≤ b :=
+theorem cast_le_cast (eq : n = m) {a b : Fin n} : a.cast eq ≤ b.cast eq ↔ a ≤ b :=
   Iff.rfl
 
 /-- The 'identity' equivalence between `Fin m` and `Fin n` when `m = n`. -/
 @[simps]
 def _root_.finCongr (eq : n = m) : Fin n ≃ Fin m where
-  toFun := cast eq
-  invFun := cast eq.symm
+  toFun := Fin.cast eq
+  invFun := Fin.cast eq.symm
   left_inv := leftInverse_cast eq
   right_inv := rightInverse_cast eq
 
@@ -656,12 +656,12 @@ a generic theorem about `cast`. -/
 lemma _root_.finCongr_eq_equivCast (h : n = m) : finCongr h = .cast (h ▸ rfl) := by subst h; simp
 
 @[simp]
-theorem cast_zero {n' : ℕ} [NeZero n] {h : n = n'} : cast h (0 : Fin n) =
+theorem cast_zero {n' : ℕ} [NeZero n] {h : n = n'} : (0 : Fin n).cast h =
     by { haveI : NeZero n' := by {rw [← h]; infer_instance}; exact 0} := rfl
 
 /-- While in many cases `Fin.cast` is better than `Equiv.cast`/`cast`, sometimes we want to apply
 a generic theorem about `cast`. -/
-theorem cast_eq_cast (h : n = m) : (cast h : Fin n → Fin m) = _root_.cast (h ▸ rfl) := by
+theorem cast_eq_cast (h : n = m) : (Fin.cast h : Fin n → Fin m) = _root_.cast (h ▸ rfl) := by
   subst h
   ext
   rfl