[Merged by Bors] - perf(FunLike.Basic): beta reduce CoeFun.coe

Archive/Sensitivity.lean

@@ -455,7 +455,6 @@ theorem huang_degree_theorem (H : Set (Q m.succ)) (hH : Card H ≥ 2 ^ m + 1) :
         |(coeffs y).sum fun (i : Q m.succ) (a : ℝ) =>
             a • (ε q ∘ f m.succ ∘ fun i : Q m.succ => e i) i| := by
       erw [(f m.succ).map_finsupp_total, (ε q).map_finsupp_total, Finsupp.total_apply]
-      rfl
     _ ≤ ∑ p in (coeffs y).support, |coeffs y p * (ε q <| f m.succ <| e p)| :=
       (norm_sum_le _ fun p => coeffs y p * _)
     _ = ∑ p in (coeffs y).support, |coeffs y p| * ite (p ∈ q.adjacent) 1 0 := by

Mathlib/Algebra/Algebra/RestrictScalars.lean

@@ -217,8 +217,8 @@ theorem RestrictScalars.ringEquiv_map_smul (r : R) (x : RestrictScalars R S A) :
 instance RestrictScalars.algebra : Algebra R (RestrictScalars R S A) :=
   { (algebraMap S A).comp (algebraMap R S) with
     smul := (· • ·)
-    commutes' := fun _ _ ↦ Algebra.commutes' _ _
-    smul_def' := fun _ _ ↦ Algebra.smul_def' _ _ }
+    commutes' := fun _ _ ↦ Algebra.commutes' (A := A) _ _
+    smul_def' := fun _ _ ↦ Algebra.smul_def' (A := A) _ _ }
 
 @[simp]
 theorem RestrictScalars.ringEquiv_algebraMap (r : R) :

Mathlib/Algebra/Category/ModuleCat/ChangeOfRings.lean

@@ -333,8 +333,8 @@ instance mulAction : MulAction S <| (restrictScalars f).obj ⟨S⟩ →ₗ[R] M
 
 instance distribMulAction : DistribMulAction S <| (restrictScalars f).obj ⟨S⟩ →ₗ[R] M :=
   { CoextendScalars.mulAction f _ with
-    smul_add := fun s g h => LinearMap.ext fun t : S => by simp
-    smul_zero := fun s => LinearMap.ext fun t : S => by simp }
+    smul_add := fun s g h => LinearMap.ext fun _ : S => by simp
+    smul_zero := fun s => LinearMap.ext fun _ : S => by simp }
 #align category_theory.Module.coextend_scalars.distrib_mul_action ModuleCat.CoextendScalars.distribMulAction
 
 /-- `S` acts on Hom(S, M) by `s • g = x ↦ g (x • s)`, this action defines an `S`-module structure on
@@ -586,8 +586,7 @@ def HomEquiv.toRestrictScalars {X Y} (g : (extendScalars f).obj X ⟶ Y) :
     letI : Module R S := Module.compHom S f
     letI : Module R Y := Module.compHom Y f
     dsimp
-    rw [RestrictScalars.smul_def, ← LinearMap.map_smul]
-    erw [tmul_smul]
+    erw [RestrictScalars.smul_def, ← LinearMap.map_smul, tmul_smul]
     congr
 #align category_theory.Module.extend_restrict_scalars_adj.hom_equiv.to_restrict_scalars ModuleCat.ExtendRestrictScalarsAdj.HomEquiv.toRestrictScalars
 
@@ -658,6 +657,7 @@ def homEquiv {X Y} :
       change S at x
       dsimp
       erw [← LinearMap.map_smul, ExtendScalars.smul_tmul, mul_one x]
+      rfl
     · rw [map_add, map_add, ih1, ih2]
   right_inv g := by
     letI m1 : Module R S := Module.compHom S f; letI m2 : Module R Y := Module.compHom Y f

Mathlib/Algebra/DirectLimit.lean

@@ -501,7 +501,6 @@ theorem of.zero_exact_aux2 {x : FreeCommRing (Σi, G i)} {s t} (hxs : IsSupporte
     dsimp only
     -- porting note: Lean 3 could get away with far fewer hints for inputs in the line below
     have := DirectedSystem.map_map (fun i j h => f' i j h) (hj p hps) hjk
-    dsimp only at this
     rw [this]
   · rintro x y ihx ihy
     rw [(restriction _).map_add, (FreeCommRing.lift _).map_add, (f' j k hjk).map_add, ihx, ihy,
@@ -529,7 +528,6 @@ theorem of.zero_exact_aux [Nonempty ι] [IsDirected ι (· ≤ ·)] {x : FreeCom
           restriction_of, dif_pos, lift_of, lift_of]
         dsimp only
         have := DirectedSystem.map_map (fun i j h => f' i j h) hij (le_refl j : j ≤ j)
-        dsimp only at this
         rw [this]
         exact sub_self _
         exacts [Or.inr rfl, Or.inl rfl]
@@ -539,8 +537,7 @@ theorem of.zero_exact_aux [Nonempty ι] [IsDirected ι (· ≤ ·)] {x : FreeCom
         -- porting note: the Lean3 proof contained `rw [restriction_of]`, but this
         -- lemma does not seem to work here
       · rw [RingHom.map_sub, RingHom.map_sub]
-        erw [lift_of, dif_pos rfl, RingHom.map_one, RingHom.map_one, lift_of,
-          RingHom.map_one, sub_self]
+        erw [lift_of, dif_pos rfl, RingHom.map_one, lift_of, RingHom.map_one, sub_self]
     · refine'
         ⟨i, {⟨i, x + y⟩, ⟨i, x⟩, ⟨i, y⟩}, _,
           isSupported_sub (isSupported_of.2 <| Or.inl rfl)

Mathlib/Algebra/Group/Hom/Defs.lean

@@ -443,7 +443,7 @@ theorem map_pow [Monoid G] [Monoid H] [MonoidHomClass F G H] (f : F) (a : G) :
 theorem map_zpow' [DivInvMonoid G] [DivInvMonoid H] [MonoidHomClass F G H]
     (f : F) (hf : ∀ x : G, f x⁻¹ = (f x)⁻¹) (a : G) : ∀ n : ℤ, f (a ^ n) = f a ^ n
   | (n : ℕ) => by rw [zpow_ofNat, map_pow, zpow_ofNat]
-  | Int.negSucc n => by rw [zpow_negSucc, hf, map_pow, ← zpow_negSucc, ← zpow_negSucc]
+  | Int.negSucc n => by rw [zpow_negSucc, hf, map_pow, ← zpow_negSucc]
 #align map_zpow' map_zpow'
 #align map_zsmul' map_zsmul'
 

Mathlib/Algebra/Homology/ModuleCat.lean

@@ -120,9 +120,8 @@ example (f g : C ⟶ D) (h : Homotopy f g) (i : ι) :
   erw [LinearMap.add_apply]
   rw [LinearMap.add_apply, prevD_eq_toPrev_dTo, dNext_eq_dFrom_fromNext]
   -- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
-  erw [comp_apply, comp_apply, comp_apply]
+  erw [comp_apply, comp_apply]
   erw [x.2, map_zero]
-  dsimp
   abel
 
 end ModuleCat

Mathlib/Algebra/Module/Torsion.lean

@@ -375,7 +375,7 @@ variable (R M)
 
 theorem torsion_gc :
     @GaloisConnection (Submodule R M) (Ideal R)ᵒᵈ _ _ annihilator fun I =>
-      torsionBySet R M <| OrderDual.ofDual I :=
+      torsionBySet R M ↑(OrderDual.ofDual I) :=
   fun _ _ =>
   ⟨fun h x hx => (mem_torsionBySet_iff _ _).mpr fun ⟨_, ha⟩ => mem_annihilator.mp (h ha) x hx,
     fun h a ha => mem_annihilator.mpr fun _ hx => (mem_torsionBySet_iff _ _).mp (h hx) ⟨a, ha⟩⟩

Mathlib/Algebra/Order/Monoid/ToMulBot.lean

@@ -36,7 +36,7 @@ theorem toMulBot_zero : toMulBot (0 : WithZero (Multiplicative α)) = Multiplica
 
 @[simp]
 theorem toMulBot_coe (x : Multiplicative α) :
-    toMulBot ↑x = Multiplicative.ofAdd (Multiplicative.toAdd x : WithBot α) :=
+    toMulBot ↑x = Multiplicative.ofAdd (↑(Multiplicative.toAdd x) : WithBot α) :=
   rfl
 #align with_zero.to_mul_bot_coe WithZero.toMulBot_coe
 

Mathlib/Algebra/Polynomial/BigOperators.lean

@@ -267,9 +267,10 @@ theorem multiset_prod_X_sub_C_coeff_card_pred (t : Multiset R) (ht : 0 < Multise
   nontriviality R
   convert multiset_prod_X_sub_C_nextCoeff (by assumption)
   rw [nextCoeff]; split_ifs with h
-  · rw [natDegree_multiset_prod_of_monic] at h <;> simp only [Multiset.mem_map] at *
+  · rw [natDegree_multiset_prod_of_monic] at h
     swap
-    · rintro _ ⟨_, _, rfl⟩
+    · simp only [Multiset.mem_map]
+      rintro _ ⟨_, _, rfl⟩
       apply monic_X_sub_C
     simp_rw [Multiset.sum_eq_zero_iff, Multiset.mem_map] at h
     contrapose! h

Mathlib/Algebra/Quaternion.lean

@@ -1267,7 +1267,7 @@ theorem im_sq : a.im ^ 2 = -normSq a.im := by
   simp_rw [sq, ← star_mul_self, im_star, neg_mul, neg_neg]
 #align quaternion.im_sq Quaternion.im_sq
 
-theorem coe_normSq_add : (normSq (a + b) : ℍ[R]) = normSq a + a * star b + b * star a + normSq b :=
+theorem coe_normSq_add : normSq (a + b) = normSq a + a * star b + b * star a + normSq b :=
   by simp only [star_add, ← self_mul_star, mul_add, add_mul, add_assoc, add_left_comm]
 #align quaternion.coe_norm_sq_add Quaternion.coe_normSq_add
 

Mathlib/Algebra/Ring/BooleanRing.lean

@@ -342,7 +342,7 @@ theorem toBoolAlg_add_add_mul (a b : α) : toBoolAlg (a + b + a * b) = toBoolAlg
 
 @[simp]
 theorem toBoolAlg_add (a b : α) : toBoolAlg (a + b) = toBoolAlg a ∆ toBoolAlg b :=
-  (ofBoolAlg_symmDiff _ _).symm
+  (ofBoolAlg_symmDiff a b).symm
 #align to_boolalg_add toBoolAlg_add
 
 /-- Turn a ring homomorphism from Boolean rings `α` to `β` into a bounded lattice homomorphism

Mathlib/AlgebraicGeometry/GammaSpecAdjunction.lean

@@ -304,10 +304,10 @@ def identityToΓSpec : 𝟭 LocallyRingedSpace.{u} ⟶ Γ.rightOp ⋙ Spec.toLoc
       -- The next six lines were `rw [ContinuousMap.coe_mk, ContinuousMap.coe_mk]` before
       -- leanprover/lean4#2644
       have : (ContinuousMap.mk (toΓSpecFun Y) (toΓSpec_continuous _)) (f.val.base x)
-        = toΓSpecFun Y (f.val.base x) := by erw [ContinuousMap.coe_mk]; rfl
+        = toΓSpecFun Y (f.val.base x) := by rw [ContinuousMap.coe_mk]
       erw [this]
       have : (ContinuousMap.mk (toΓSpecFun X) (toΓSpec_continuous _)) x
-        = toΓSpecFun X x := by erw [ContinuousMap.coe_mk]
+        = toΓSpecFun X x := by rw [ContinuousMap.coe_mk]
       erw [this]
       dsimp [toΓSpecFun]
       -- This used to be `rw`, but we need `erw` after leanprover/lean4#2644

Mathlib/AlgebraicGeometry/PrimeSpectrum/Basic.lean

@@ -485,7 +485,7 @@ theorem vanishingIdeal_strict_anti_mono_iff {s t : Set (PrimeSpectrum R)} (hs :
 /-- The antitone order embedding of closed subsets of `Spec R` into ideals of `R`. -/
 def closedsEmbedding (R : Type*) [CommRing R] :
     (TopologicalSpace.Closeds <| PrimeSpectrum R)ᵒᵈ ↪o Ideal R :=
-  OrderEmbedding.ofMapLEIff (fun s => vanishingIdeal <| OrderDual.ofDual s) fun s _ =>
+  OrderEmbedding.ofMapLEIff (fun s => vanishingIdeal ↑(OrderDual.ofDual s)) fun s _ =>
     (vanishingIdeal_anti_mono_iff s.2).symm
 #align prime_spectrum.closeds_embedding PrimeSpectrum.closedsEmbedding
 

Mathlib/AlgebraicGeometry/Scheme.lean

@@ -342,7 +342,7 @@ lemma basicOpen_restrict (i : V ⟶ U) (f : X.presheaf.obj (op U)) :
 theorem preimage_basicOpen {X Y : Scheme} (f : X ⟶ Y) {U : Opens Y.carrier}
     (r : Y.presheaf.obj <| op U) :
     (Opens.map f.1.base).obj (Y.basicOpen r) =
-      @Scheme.basicOpen X ((Opens.map f.1.base).obj U) (f.1.c.app _ r) :=
+      @Scheme.basicOpen X ((Opens.map f.1.base).obj U) (f.1.c.app (op U) r) :=
   LocallyRingedSpace.preimage_basicOpen f r
 #align algebraic_geometry.Scheme.preimage_basic_open AlgebraicGeometry.Scheme.preimage_basicOpen
 

Mathlib/AlgebraicGeometry/Spec.lean

@@ -262,9 +262,9 @@ def Spec.locallyRingedSpaceMap {R S : CommRingCat} (f : R ⟶ S) :
       replace ha := (stalkIso S p).hom.isUnit_map ha
       rw [← comp_apply, show localizationToStalk S p = (stalkIso S p).inv from rfl,
         Iso.inv_hom_id, id_apply] at ha
-      -- Porting note : `R` had to be made explicit
+      -- Porting note : `f` had to be made explicit
       replace ha := IsLocalRingHom.map_nonunit
-        (R := Localization.AtPrime (PrimeSpectrum.comap f p).asIdeal) _ ha
+        (f := (Localization.localRingHom (PrimeSpectrum.comap f p).asIdeal p.asIdeal f _)) _ ha
       convert RingHom.isUnit_map (stalkIso R (PrimeSpectrum.comap f p)).inv ha
       erw [← comp_apply, show stalkToFiberRingHom R _ = (stalkIso _ _).hom from rfl,
         Iso.hom_inv_id, id_apply]

Mathlib/AlgebraicGeometry/StructureSheaf.lean

@@ -483,7 +483,7 @@ def localizationToStalk (x : PrimeSpectrum.Top R) :
 @[simp]
 theorem localizationToStalk_of (x : PrimeSpectrum.Top R) (f : R) :
     localizationToStalk R x (algebraMap _ (Localization _) f) = toStalk R x f :=
-  IsLocalization.lift_eq _ f
+  IsLocalization.lift_eq (S := Localization x.asIdeal.primeCompl) _ f
 #align algebraic_geometry.structure_sheaf.localization_to_stalk_of AlgebraicGeometry.StructureSheaf.localizationToStalk_of
 
 @[simp]

Mathlib/Analysis/Calculus/AffineMap.lean

@@ -32,7 +32,6 @@ variable [NormedAddCommGroup W] [NormedSpace 𝕜 W]
 theorem contDiff {n : ℕ∞} (f : V →A[𝕜] W) : ContDiff 𝕜 n f := by
   rw [f.decomp]
   apply f.contLinear.contDiff.add
-  simp only
   exact contDiff_const
 #align continuous_affine_map.cont_diff ContinuousAffineMap.contDiff
 

Mathlib/Analysis/Convex/Between.lean

@@ -538,7 +538,6 @@ theorem Sbtw.affineCombination_of_mem_affineSpan_pair [NoZeroDivisors R] [NoZero
   rw [hr i his, sbtw_mul_sub_add_iff] at hs
   change ∀ i ∈ s, w i = (r • (w₂ - w₁) + w₁) i at hr
   rw [s.affineCombination_congr hr fun _ _ => rfl]
-  dsimp only
   rw [← s.weightedVSub_vadd_affineCombination, s.weightedVSub_const_smul,
     ← s.affineCombination_vsub, ← lineMap_apply, sbtw_lineMap_iff, and_iff_left hs.2,
     ← @vsub_ne_zero V, s.affineCombination_vsub]

Mathlib/Analysis/Fourier/AddCircle.lean

@@ -570,7 +570,6 @@ theorem fourierCoeffOn_of_hasDerivAt {a b : ℝ} (hab : a < b) {f f' : ℝ → 
   conv => pattern (occs := 1 2 3) fourier _ _ * _ <;> (rw [mul_comm])
   rw [integral_mul_deriv_eq_deriv_mul hf (fun x _ => has_antideriv_at_fourier_neg hT hn x) hf'
     (((map_continuous (fourier (-n))).comp (AddCircle.continuous_mk' _)).intervalIntegrable _ _)]
-  dsimp only
   have : ∀ u v w : ℂ, u * ((b - a : ℝ) / v * w) = (b - a : ℝ) / v * (u * w) := by intros; ring
   conv in intervalIntegral _ _ _ _ => congr; ext; rw [this]
   rw [(by ring : ((b - a : ℝ) : ℂ) / (-2 * π * I * n) = ((b - a : ℝ) : ℂ) * (1 / (-2 * π * I * n)))]

Mathlib/Analysis/Fourier/FourierTransform.lean

@@ -104,9 +104,7 @@ theorem fourierIntegral_comp_add_right [MeasurableAdd V] (e : Multiplicative 
   ext1 w
   dsimp only [fourierIntegral, Function.comp_apply]
   conv in L _ => rw [← add_sub_cancel v v₀]
-  rw [integral_add_right_eq_self fun v : V => e[-L (v - v₀) w] • f v]
-  dsimp only
-  rw [← integral_smul]
+  rw [integral_add_right_eq_self fun v : V => e[-L (v - v₀) w] • f v, ← integral_smul]
   congr 1 with v
   rw [← smul_assoc, smul_eq_mul, ← Submonoid.coe_mul, ← e.map_mul, ← ofAdd_add, ←
     LinearMap.neg_apply, ← sub_eq_add_neg, ← LinearMap.sub_apply, LinearMap.map_sub, neg_sub]

Mathlib/Analysis/SpecialFunctions/Complex/Arg.lean

@@ -141,7 +141,6 @@ theorem arg_mem_Ioc (z : ℂ) : arg z ∈ Set.Ioc (-π) π := by
   rcases existsUnique_add_zsmul_mem_Ioc Real.two_pi_pos (arg z) (-π) with ⟨N, hN, -⟩
   rw [two_mul, neg_add_cancel_left, ← two_mul, zsmul_eq_mul] at hN
   rw [← abs_mul_cos_add_sin_mul_I z, ← cos_add_int_mul_two_pi _ N, ← sin_add_int_mul_two_pi _ N]
-  simp only [← ofReal_one, ← ofReal_bit0, ← ofReal_mul, ← ofReal_add, ofReal_int_cast]
   have := arg_mul_cos_add_sin_mul_I (abs.pos hz) hN
   push_cast at this
   rwa [this]

Mathlib/CategoryTheory/Limits/Opposites.lean

@@ -790,14 +790,14 @@ noncomputable def pullbackIsoUnopPushout {X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z)
 theorem pullbackIsoUnopPushout_inv_fst {X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z) [HasPullback f g]
     [HasPushout f.op g.op] :
     (pullbackIsoUnopPushout f g).inv ≫ pullback.fst = (pushout.inl : _ ⟶ pushout f.op g.op).unop :=
-  (IsLimit.conePointUniqueUpToIso_inv_comp _ _ _).trans (by simp)
+  (IsLimit.conePointUniqueUpToIso_inv_comp _ _ _).trans (by simp [unop_id (X := { unop := X })])
 #align category_theory.limits.pullback_iso_unop_pushout_inv_fst CategoryTheory.Limits.pullbackIsoUnopPushout_inv_fst
 
 @[reassoc (attr := simp)]
 theorem pullbackIsoUnopPushout_inv_snd {X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z) [HasPullback f g]
     [HasPushout f.op g.op] :
     (pullbackIsoUnopPushout f g).inv ≫ pullback.snd = (pushout.inr : _ ⟶ pushout f.op g.op).unop :=
-  (IsLimit.conePointUniqueUpToIso_inv_comp _ _ _).trans (by simp)
+  (IsLimit.conePointUniqueUpToIso_inv_comp _ _ _).trans (by simp [unop_id (X := { unop := Y })])
 #align category_theory.limits.pullback_iso_unop_pushout_inv_snd CategoryTheory.Limits.pullbackIsoUnopPushout_inv_snd
 
 @[reassoc (attr := simp)]

Mathlib/CategoryTheory/SingleObj.lean

@@ -231,7 +231,7 @@ set_option linter.uppercaseLean3 false in
 #align Mon.to_Cat_full MonCat.toCatFull
 
 instance toCat_faithful : Faithful toCat where
-  map_injective h := by simpa [toCat] using h
+  map_injective h := by rwa [toCat, (SingleObj.mapHom _ _).apply_eq_iff_eq] at h
 set_option linter.uppercaseLean3 false in
 #align Mon.to_Cat_faithful MonCat.toCat_faithful
 

Mathlib/Data/Finset/Image.lean

@@ -66,7 +66,7 @@ variable {f : α ↪ β} {s : Finset α}
 
 @[simp]
 theorem mem_map {b : β} : b ∈ s.map f ↔ ∃ a ∈ s, f a = b :=
-  mem_map.trans <| by simp only [exists_prop]; rfl
+  Multiset.mem_map
 #align finset.mem_map Finset.mem_map
 
 --Porting note: Higher priority to apply before `mem_map`.

Mathlib/Data/Finsupp/Basic.lean

@@ -1401,7 +1401,7 @@ section
 
 variable [Zero M] [MonoidWithZero R] [MulActionWithZero R M]
 
-@[simp]
+@[simp, nolint simpNF] -- `simpNF` incorrectly complains the LHS doesn't simplify.
 theorem single_smul (a b : α) (f : α → M) (r : R) : single a r b • f a = single a (r • f b) b := by
   by_cases h : a = b <;> simp [h]
 #align finsupp.single_smul Finsupp.single_smul

Mathlib/Data/Finsupp/Defs.lean

@@ -774,7 +774,7 @@ theorem mapRange_apply {f : M → N} {hf : f 0 = 0} {g : α →₀ M} {a : α} :
 
 @[simp]
 theorem mapRange_zero {f : M → N} {hf : f 0 = 0} : mapRange f hf (0 : α →₀ M) = 0 :=
-  ext fun a => by simp only [hf, zero_apply, mapRange_apply]
+  ext fun _ => by simp only [hf, zero_apply, mapRange_apply]
 #align finsupp.map_range_zero Finsupp.mapRange_zero
 
 @[simp]

Mathlib/Data/Finsupp/Pointwise.lean

@@ -108,7 +108,7 @@ instance pointwiseScalar [Semiring β] : SMul (α → β) (α →₀ β) where
 #align finsupp.pointwise_scalar Finsupp.pointwiseScalar
 
 @[simp]
-theorem coe_pointwise_smul [Semiring β] (f : α → β) (g : α →₀ β) : FunLike.coe (f • g) = f • g :=
+theorem coe_pointwise_smul [Semiring β] (f : α → β) (g : α →₀ β) : ⇑(f • g) = f • ⇑g :=
   rfl
 #align finsupp.coe_pointwise_smul Finsupp.coe_pointwise_smul
 

Mathlib/Data/FunLike/Basic.lean

@@ -146,7 +146,8 @@ namespace FunLike
 
 variable {F α β} [i : FunLike F α β]
 
-instance (priority := 100) hasCoeToFun : CoeFun F fun _ ↦ ∀ a : α, β a where coe := FunLike.coe
+instance (priority := 100) hasCoeToFun : CoeFun F (fun _ ↦ ∀ a : α, β a) where
+  coe := @FunLike.coe _ _ β _ -- need to make explicit to beta reduce for non-dependent functions
 
 #eval Lean.Elab.Command.liftTermElabM do
   Std.Tactic.Coe.registerCoercion ``FunLike.coe

Mathlib/Data/IsROrC/Basic.lean

@@ -830,11 +830,11 @@ noncomputable instance Real.isROrC : IsROrC ℝ where
   mul_re_ax z w := by simp only [sub_zero, mul_zero, AddMonoidHom.zero_apply, AddMonoidHom.id_apply]
   mul_im_ax z w := by simp only [add_zero, zero_mul, mul_zero, AddMonoidHom.zero_apply]
   conj_re_ax z := by simp only [starRingEnd_apply, star_id_of_comm]
-  conj_im_ax z := by simp only [neg_zero, AddMonoidHom.zero_apply]
+  conj_im_ax _ := by simp only [neg_zero, AddMonoidHom.zero_apply]
   conj_I_ax := by simp only [RingHom.map_zero, neg_zero]
   norm_sq_eq_def_ax z := by simp only [sq, Real.norm_eq_abs, ← abs_mul, abs_mul_self z, add_zero,
     mul_zero, AddMonoidHom.zero_apply, AddMonoidHom.id_apply]
-  mul_im_I_ax z := by simp only [mul_zero, AddMonoidHom.zero_apply]
+  mul_im_I_ax _ := by simp only [mul_zero, AddMonoidHom.zero_apply]
   le_iff_re_im := (and_iff_left rfl).symm
 #align real.is_R_or_C Real.isROrC
 

Mathlib/Data/MvPolynomial/Basic.lean

@@ -1702,7 +1702,7 @@ theorem eval₂_mem {f : R →+* S} {p : MvPolynomial σ R} {s : subS}
     · subst h
       rw [MvPolynomial.not_mem_support_iff.1 ha, map_zero]
       exact zero_mem _
-    · rwa [if_neg h, zero_add] at this
+    · rwa [zero_add] at this
 #align mv_polynomial.eval₂_mem MvPolynomial.eval₂_mem
 
 theorem eval_mem {p : MvPolynomial σ S} {s : subS} (hs : ∀ i ∈ p.support, p.coeff i ∈ s) {v : σ → S}

Mathlib/Data/Nat/Factorization/Basic.lean

@@ -429,7 +429,7 @@ theorem factorization_prime_le_iff_dvd {d n : ℕ} (hd : d ≠ 0) (hn : n ≠ 0)
     (∀ p : ℕ, p.Prime → d.factorization p ≤ n.factorization p) ↔ d ∣ n := by
   rw [← factorization_le_iff_dvd hd hn]
   refine' ⟨fun h p => (em p.Prime).elim (h p) fun hp => _, fun h p _ => h p⟩
-  simp_rw [factorization_eq_zero_of_non_prime _ hp, le_refl]
+  simp_rw [factorization_eq_zero_of_non_prime _ hp]
 #align nat.factorization_prime_le_iff_dvd Nat.factorization_prime_le_iff_dvd
 
 theorem pow_succ_factorization_not_dvd {n p : ℕ} (hn : n ≠ 0) (hp : p.Prime) :

Mathlib/Data/Polynomial/RingDivision.lean

@@ -1328,7 +1328,7 @@ theorem card_roots_le_map [IsDomain A] [IsDomain B] {p : A[X]} {f : A →+* B} (
 theorem card_roots_le_map_of_injective [IsDomain A] [IsDomain B] {p : A[X]} {f : A →+* B}
     (hf : Function.Injective f) : Multiset.card p.roots ≤ Multiset.card (p.map f).roots := by
   by_cases hp0 : p = 0
-  · simp only [hp0, roots_zero, Polynomial.map_zero, Multiset.card_zero]; rfl
+  · simp only [hp0, roots_zero, Polynomial.map_zero, Multiset.card_zero]
   exact card_roots_le_map ((Polynomial.map_ne_zero_iff hf).mpr hp0)
 #align polynomial.card_roots_le_map_of_injective Polynomial.card_roots_le_map_of_injective
 

Mathlib/Data/ZMod/Basic.lean

@@ -794,7 +794,7 @@ def chineseRemainder {m n : ℕ} (h : m.Coprime n) : ZMod (m * n) ≃+* ZMod m 
   let to_fun : ZMod (m * n) → ZMod m × ZMod n :=
     ZMod.castHom (show m.lcm n ∣ m * n by simp [Nat.lcm_dvd_iff]) (ZMod m × ZMod n)
   let inv_fun : ZMod m × ZMod n → ZMod (m * n) := fun x =>
-    if m * n = 0 then if m = 1 then RingHom.snd _ _ x else RingHom.fst _ _ x
+    if m * n = 0 then if m = 1 then RingHom.snd _ (ZMod n) x else RingHom.fst (ZMod m) _ x
     else Nat.chineseRemainder h x.1.val x.2.val
   have inv : Function.LeftInverse inv_fun to_fun ∧ Function.RightInverse inv_fun to_fun :=
     if hmn0 : m * n = 0 then by