mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.Valuation.ValuationSubring

Goal state before:
pp: case neg
K : Type u
inst✝ : Field K
A B : ValuationSubring K
h : B.nonunits ≤ A.nonunits
x : K
hx : ¬1 < A.valuation x
h_1 : ¬x = 0
⊢ ¬1 < B.valuation x

Tactic:
Valuation.one_lt_val_iff _ h_1

Goal state after:
case neg
K : Type u
inst✝ : Field K
A B : ValuationSubring K
h : B.nonunits ≤ A.nonunits
x : K
hx : ¬A.valuation x⁻¹ < 1
h_1 : ¬x = 0
⊢ ¬B.valuation x⁻¹ < 1
Module: Mathlib.Algebra.Order.Module.HahnEmbedding

Goal state before:
pp: K : Type u_1
inst✝¹³ : DivisionRing K
inst✝¹² : LinearOrder K
inst✝¹¹ : IsOrderedRing K
inst✝¹⁰ : Archimedean K
M : Type u_2
inst✝⁹ : AddCommGroup M
inst✝⁸ : LinearOrder M
inst✝⁷ : IsOrderedAddMonoid M
inst✝⁶ : Module K M
inst✝⁵ : IsOrderedModule K M
R : Type u_3
inst✝⁴ : AddCommGroup R
inst✝³ : LinearOrder R
inst✝² : Module K R
seed : Seed K M R
f : Partial seed
inst✝¹ : IsOrderedAddMonoid R
inst✝ : Archimedean R
x : M
hx : x ∉ (↑f).domain
hx' : ∀ {c : K}, c ≠ 0 → -c • x ∉ (↑f).domain
y z : ↥(f.extendFun hx).domain
hyzmem : ↑(z - y) ∈ (↑f).domain ⊔ K ∙ x
a : M
ha : a ∈ (↑f).domain
b : M
hb : b ∈ K ∙ x
hab : a + b = ↑(z - y)
hyz : 0 < ⟨a + b, ⋯⟩
this : z - y = ⟨a + b, ⋯⟩
⊢ 0 < a + b

Tactic:
exact hyz

Goal state after:
Module: Mathlib.Algebra.Order.Ring.StandardPart

Goal state before:
pp: K : Type u_1
inst✝² : LinearOrder K
inst✝¹ : Field K
inst✝ : IsOrderedRing K
x y : K
hx : 0 ≤ mk x
hy : 0 ≤ -mk y
⊢ stdPart x * stdPart y⁻¹ = stdPart x * (stdPart y)⁻¹

pp: K : Type u_1
inst✝² : LinearOrder K
inst✝¹ : Field K
inst✝ : IsOrderedRing K
x y : K
hx : 0 ≤ mk x
hy : 0 ≤ -mk y
⊢ 0 ≤ mk y⁻¹

Tactic:
stdPart_inv

Goal state after:
K : Type u_1
inst✝² : LinearOrder K
inst✝¹ : Field K
inst✝ : IsOrderedRing K
x y : K
hx : 0 ≤ mk x
hy : 0 ≤ -mk y
⊢ stdPart x * (stdPart y)⁻¹ = stdPart x * (stdPart y)⁻¹

K : Type u_1
inst✝² : LinearOrder K
inst✝¹ : Field K
inst✝ : IsOrderedRing K
x y : K
hx : 0 ≤ mk x
hy : 0 ≤ -mk y
⊢ 0 ≤ mk y⁻¹
Module: Mathlib.Algebra.Order.Ring.StandardPart

Goal state before:
pp: case inl
K : Type u_1
inst✝² : LinearOrder K
inst✝¹ : Field K
inst✝ : IsOrderedRing K
f : ℝ →+*o K
x : K
hx : 0 ≤ mk x
a : ℤ
ha : ↑a < x
b : ℤ
hb✝ : x < ↑b
hn : {r | x < f r}.Nonempty
hb : BddBelow {r | x < f r}
⊢ stdPart x = sInf {r | x < f r}

Tactic:
apply stdPart_eq f

Goal state after:
case inl.hl
K : Type u_1
inst✝² : LinearOrder K
inst✝¹ : Field K
inst✝ : IsOrderedRing K
f : ℝ →+*o K
x : K
hx : 0 ≤ mk x
a : ℤ
ha : ↑a < x
b : ℤ
hb✝ : x < ↑b
hn : {r | x < f r}.Nonempty
hb : BddBelow {r | x < f r}
⊢ ∀ s < sInf {r | x < f r}, f s ≤ x

case inl.hr
K : Type u_1
inst✝² : LinearOrder K
inst✝¹ : Field K
inst✝ : IsOrderedRing K
f : ℝ →+*o K
x : K
hx : 0 ≤ mk x
a : ℤ
ha : ↑a < x
b : ℤ
hb✝ : x < ↑b
hn : {r | x < f r}.Nonempty
hb : BddBelow {r | x < f r}
⊢ ∀ s > sInf {r | x < f r}, x ≤ f s
Module: Mathlib.Algebra.Polynomial.Degree.CardPowDegree

Goal state before:
pp: Fq : Type u_1
inst✝¹ : Field Fq
inst✝ : Fintype Fq
card_pos : 0 < Fintype.card Fq
pow_pos : ∀ (n : ℕ), 0 < ↑(Fintype.card Fq) ^ n
this : DecidableEq Fq := Classical.decEq Fq
p : Fq[X]
h : ¬p = 0 → ↑(Fintype.card Fq) ^ p.natDegree = 0
⊢ p = 0

Tactic:
by
          contrapose! h
          exact ⟨h, (pow_pos _).ne'⟩

Goal state after:
Module: Mathlib.Algebra.Polynomial.CoeffMem

Goal state before:
pp: case hy
R : Type u_2
S : Type u_3
inst✝² : CommRing R
inst✝¹ : Ring S
inst✝ : Algebra R S
p q : S[X]
hq : q.Monic
i✝ : ℕ
H₀ : ∀ (i : ℕ), p.coeff i ∈ spanCoeffs(q) ^ deg(p) * spanCoeffs(p)
hpq : q.degree ≤ p.degree ∧ p ≠ 0
r : S[X]
hr : p - q * (C p.leadingCoeff * X ^ (deg(p) - deg(q))) = r
hr' : ¬r = 0
i : ℕ
⊢ (if deg(p) - deg(q) ≤ i then q.coeff (i - (deg(p) - deg(q))) * p.leadingCoeff else 0) ∈
    span R coeffs(p) ⊔ span R coeffs(q) * span R coeffs(p)

Tactic:
split_ifs
        · refine SetLike.le_def.mp le_sup_right (mul_mem_mul ?_ ?_) <;> exact subset_span ⟨_, rfl⟩
        · exact zero_mem _

Goal state after:
Module: Mathlib.Algebra.Polynomial.Degree.IsMonicOfDegree

Goal state before:
pp: R : Type u_1
inst✝¹ : Semiring R
inst✝ : Nontrivial R
f : R[X]
⊢ f.IsMonicOfDegree 1 ↔ ∃ r, f = X + C r

Tactic:
by
  refine ⟨fun H ↦ ?_, fun ⟨r, H⟩ ↦ H ▸ isMonicOfDegree_X_add_one r⟩
  refine ⟨f.coeff 0, ?_⟩
  ext1 n
  rcases n.eq_zero_or_pos with rfl | hn
  · simp
  · exact H.coeff_eq (isMonicOfDegree_X_add_one _) (by lia)

Goal state after:
Module: Mathlib.Algebra.Order.Module.HahnEmbedding

Goal state before:
pp: K : Type u_1
inst✝¹² : DivisionRing K
inst✝¹¹ : LinearOrder K
inst✝¹⁰ : IsOrderedRing K
inst✝⁹ : Archimedean K
M : Type u_2
inst✝⁸ : AddCommGroup M
inst✝⁷ : LinearOrder M
inst✝⁶ : IsOrderedAddMonoid M
inst✝⁵ : Module K M
inst✝⁴ : IsOrderedModule K M
R : Type u_3
inst✝³ : AddCommGroup R
inst✝² : LinearOrder R
inst✝¹ : Module K R
seed : Seed K M R
inst✝ : IsOrderedAddMonoid R
c : Set (Partial seed)
hc : IsChain (fun x1 x2 ↦ x1 ≤ x2) c
⊢ c.Nonempty → BddAbove c

Tactic:
hnonempty

Goal state after:
K : Type u_1
inst✝¹² : DivisionRing K
inst✝¹¹ : LinearOrder K
inst✝¹⁰ : IsOrderedRing K
inst✝⁹ : Archimedean K
M : Type u_2
inst✝⁸ : AddCommGroup M
inst✝⁷ : LinearOrder M
inst✝⁶ : IsOrderedAddMonoid M
inst✝⁵ : Module K M
inst✝⁴ : IsOrderedModule K M
R : Type u_3
inst✝³ : AddCommGroup R
inst✝² : LinearOrder R
inst✝¹ : Module K R
seed : Seed K M R
inst✝ : IsOrderedAddMonoid R
c : Set (Partial seed)
hc : IsChain (fun x1 x2 ↦ x1 ≤ x2) c
hnonempty : c.Nonempty
⊢ BddAbove c
Module: Mathlib.Algebra.Polynomial.Homogenize

Goal state before:
pp: case add
R : Type u_1
inst✝ : CommSemiring R
n : ℕ
m : Fin 2 →₀ ℕ
p q : R[X]
ihp : MvPolynomial.coeff m (p.homogenize n) = if m 0 + m 1 = n then p.coeff (m 0) else 0
ihq : MvPolynomial.coeff m (q.homogenize n) = if m 0 + m 1 = n then q.coeff (m 0) else 0
⊢ MvPolynomial.coeff m ((p + q).homogenize n) = if m 0 + m 1 = n then (p + q).coeff (m 0) else 0

Tactic:
| add p q ihp ihq =>

Goal state after:
Module: Mathlib.Algebra.Polynomial.Homogenize

Goal state before:
pp: R : Type u_1
inst✝ : CommSemiring R
ι : Type u_2
s : Finset ι
p : ι → R[X]
n : ι → ℕ
h : ∀ i ∈ s, (p i).natDegree ≤ n i
⊢ (∏ i ∈ s, p i).homogenize (∑ i ∈ s, n i) = ∏ i ∈ s, (p i).homogenize (n i)

Tactic:
induction s using Finset.cons_induction with

Goal state after:
Module: Mathlib.Algebra.Polynomial.Homogenize

Goal state before:
pp: case inr.inr
R : Type u_1
inst✝¹ : CommSemiring R
inst✝ : NoZeroDivisors R
p r : R[X]
hp₀ : p ≠ 0
hr₀ : r ≠ 0
⊢ p.homogenize p.natDegree ∣ p.homogenize p.natDegree * r.homogenize r.natDegree

Tactic:
apply dvd_mul_right

Goal state after:
Module: Mathlib.Algebra.Polynomial.Smeval

Goal state before:
pp: R : Type u_1
inst✝³ : Semiring R
S : Type u_2
inst✝² : AddCommMonoid S
inst✝¹ : Pow S ℕ
inst✝ : MulActionWithZero R S
x : S
⊢ smeval 0 x = 0

Tactic:
by
  simp only [smeval_eq_sum, sum_zero_index]

Goal state after:
Module: Mathlib.Algebra.Polynomial.Smeval

Goal state before:
pp: case monomial
R : Type u_1
inst✝⁴ : Semiring R
p : R[X]
S : Type u_2
inst✝³ : Semiring S
inst✝² : Module R S
inst✝¹ : IsScalarTower R S S
inst✝ : SMulCommClass R S S
x y : S
hc : Commute x y
n : ℕ
a : R
⊢ Commute (((monomial n) a).smeval x) y

Tactic:
simpa [smeval_monomial] using Commute.smul_left (Commute.pow_left hc _) _

Goal state after:
Module: Mathlib.Algebra.Polynomial.Smeval

Goal state before:
pp: R : Type u_1
inst✝² : CommSemiring R
S : Type u_2
inst✝¹ : Semiring S
inst✝ : Algebra R S
x : S
p : R[X]
⊢ (p.sum fun e a ↦ a • x ^ e) = p.sum (smul_pow x)

Tactic:
exact rfl

Goal state after:
Module: Mathlib.Algebra.Polynomial.UnitTrinomial

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
k m n : ℕ
u v w : R
hkm : k < m
hmn : m < n
hw : w ≠ 0
⊢ (trinomial k m n u v w).leadingCoeff = w

Tactic:
rw [leadingCoeff, trinomial_natDegree hkm hmn hw, trinomial_leading_coeff' hkm hmn]

Goal state after:
Module: Mathlib.Algebra.Polynomial.PartialFractions

Goal state before:
pp: R : Type u_1
inst✝² : CommRing R
inst✝¹ : Nontrivial R
ι : Type u_2
inst✝ : DecidableEq ι
s : Finset ι
f : R[X]
g : ι → R[X]
hg : ∀ i ∈ s, (g i).Monic
hgg : (↑s).Pairwise fun i j ↦ IsCoprime (g i) (g j)
⊢ ∃ q r, (∀ i ∈ s, (r i).degree < (g i).degree) ∧ f = q * ∏ i ∈ s, g i + ∑ i ∈ s, r i * ∏ k ∈ s.erase i, g k

Tactic:
induction s using Finset.cons_induction with

Goal state after:
Module: Mathlib.Algebra.Polynomial.SumIteratedDerivative

Goal state before:
pp: case inr
R : Type u_1
inst✝² : CommSemiring R
A : Type u_3
inst✝¹ : CommRing A
inst✝ : Algebra R A
p : R[X]
q k : ℕ
hk : q ≤ k
gp : R[X]
gp_le : gp.natDegree ≤ p.natDegree - k
h : ∀ (r : A), (aeval r) ((⇑derivative)^[k] p) = q ! • (aeval r) gp
⊢ ∃ gp,
    gp.natDegree ≤ p.natDegree - q ∧
      ∀ (r : A), (X - C r) ^ q ∣ map (algebraMap R A) p → (aeval r) ((⇑derivative)^[k] p) = q ! • (aeval r) gp

Tactic:
exact ⟨gp, gp_le.trans (tsub_le_tsub_left hk _), fun r _ => h r⟩

Goal state after:
Module: Mathlib.Algebra.Polynomial.PartialFractions

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
ι : Type u_2
inst✝ : DecidableEq ι
g : ι → R[X]
i : ι
s : Finset ι
hi : i ∉ s
hgg : (↑(Finset.cons i s hi)).Pairwise fun i j ↦ IsCoprime (g i) (g j)
⊢ IsCoprime (g i) (∏ i ∈ s, g i)

Tactic:
induction s using Finset.cons_induction with

Goal state after:
Module: Mathlib.Algebra.Polynomial.RuleOfSigns

Goal state before:
pp: R : Type u_1
inst✝² : Ring R
inst✝¹ : LinearOrder R
inst✝ : IsStrictOrderedRing R
P : R[X]
η : R
hη : 0 < η
hP₀ : 0 < P.leadingCoeff
hc : P.nextCoeff < 0
d : ℕ
hd : P.natDegree = d + 1
hPn0 : P ≠ 0
⊢ ((X - C η) * P).natDegree = P.natDegree + 1

Tactic:
natDegree_mul (X_sub_C_ne_zero η) hPn0,

Goal state after:
R : Type u_1
inst✝² : Ring R
inst✝¹ : LinearOrder R
inst✝ : IsStrictOrderedRing R
P : R[X]
η : R
hη : 0 < η
hP₀ : 0 < P.leadingCoeff
hc : P.nextCoeff < 0
d : ℕ
hd : P.natDegree = d + 1
hPn0 : P ≠ 0
⊢ (X - C η).natDegree + P.natDegree = P.natDegree + 1
Module: Mathlib.Algebra.Polynomial.SumIteratedDerivative

Goal state before:
pp: case inr
R : Type u_1
inst✝⁴ : CommSemiring R
A : Type u_3
inst✝³ : CommRing A
inst✝² : Algebra R A
inst✝¹ : Nontrivial A
inst✝ : NoZeroDivisors A
p : R[X]
q : ℕ
hq : 0 < q
inj_amap : Function.Injective ⇑(algebraMap R A)
p0 : p ≠ 0
⊢ ∃ gp,
    gp.natDegree ≤ p.natDegree - q ∧
      ∀ (r : A) {p' : A[X]},
        map (algebraMap R A) p = (X - C r) ^ (q - 1) * p' →
          (aeval r) (sumIDeriv p) = (q - 1)! • eval r p' + q ! • (aeval r) gp

Tactic:
let c k := if hk : q ≤ k then (aeval_iterate_derivative_of_ge A p q hk).choose else 0

Goal state after:
case inr
R : Type u_1
inst✝⁴ : CommSemiring R
A : Type u_3
inst✝³ : CommRing A
inst✝² : Algebra R A
inst✝¹ : Nontrivial A
inst✝ : NoZeroDivisors A
p : R[X]
q : ℕ
hq : 0 < q
inj_amap : Function.Injective ⇑(algebraMap R A)
p0 : p ≠ 0
c : ℕ → R[X] := fun k ↦ if hk : q ≤ k then ⋯.choose else 0
⊢ ∃ gp,
    gp.natDegree ≤ p.natDegree - q ∧
      ∀ (r : A) {p' : A[X]},
        map (algebraMap R A) p = (X - C r) ^ (q - 1) * p' →
          (aeval r) (sumIDeriv p) = (q - 1)! • eval r p' + q ! • (aeval r) gp
Module: Mathlib.Algebra.Polynomial.RuleOfSigns

Goal state before:
pp: R : Type u_1
inst✝² : Ring R
inst✝¹ : LinearOrder R
inst✝ : IsStrictOrderedRing R
P : R[X]
η : R
hη : 0 < η
hP₀ : 0 < P.leadingCoeff
hc : P.nextCoeff < 0
d : ℕ
hd : P.natDegree = d + 1
hndxP : ((X - C η) * P).natDegree = P.natDegree + 1
hndxeP : ((X - C η) * P.eraseLead).natDegree = P.natDegree
hQ : ((X - C η) * P).nextCoeff = P.coeff d - η * P.coeff (d + 1)
hQ₁ : ((X - C η) * P).nextCoeff < 0
hndexP0 : ((X - C η) * P).eraseLead.natDegree = P.natDegree
⊢ ((X - C η) * P).eraseLead - (monomial ((X - C η) * P).eraseLead.natDegree) ((X - C η) * P).nextCoeff =
    ((X - C η) * P.eraseLead).eraseLead

Tactic:
hndexP0,

Goal state after:
R : Type u_1
inst✝² : Ring R
inst✝¹ : LinearOrder R
inst✝ : IsStrictOrderedRing R
P : R[X]
η : R
hη : 0 < η
hP₀ : 0 < P.leadingCoeff
hc : P.nextCoeff < 0
d : ℕ
hd : P.natDegree = d + 1
hndxP : ((X - C η) * P).natDegree = P.natDegree + 1
hndxeP : ((X - C η) * P.eraseLead).natDegree = P.natDegree
hQ : ((X - C η) * P).nextCoeff = P.coeff d - η * P.coeff (d + 1)
hQ₁ : ((X - C η) * P).nextCoeff < 0
hndexP0 : ((X - C η) * P).eraseLead.natDegree = P.natDegree
⊢ ((X - C η) * P).eraseLead - (monomial P.natDegree) ((X - C η) * P).nextCoeff = ((X - C η) * P.eraseLead).eraseLead
Module: Mathlib.Algebra.Polynomial.UnitTrinomial

Goal state before:
pp: p q : ℤ[X]
k m m' n : ℕ
hkm : k < m
hmn : m < n
hkm' : k < m'
hmn' : m' < n
u v w : ℤˣ
hp : p = trinomial k m n ↑u ↑v ↑w
hq : q = trinomial k m' n ↑u ↑v ↑w
f : ℤ[X] → ℤ[X] :=
  fun p ↦
    { toFinsupp := AddMonoidAlgebra.ofCoeff (Finsupp.filter (fun x ↦ x ∈ Set.Ioo (k + n) (n + n)) p.toFinsupp.coeff) }
h :
  C ↑v * (C ↑u * X ^ (m + n) + C ↑w * X ^ (n - m + k + n)) = C ↑v * (C ↑u * X ^ (m' + n) + C ↑w * X ^ (n - m' + k + n))
⊢ q = p ∨ q = p.mirror

Tactic:
(isUnit_C.mpr v.isUnit).mul_right_inj

Goal state after:
p q : ℤ[X]
k m m' n : ℕ
hkm : k < m
hmn : m < n
hkm' : k < m'
hmn' : m' < n
u v w : ℤˣ
hp : p = trinomial k m n ↑u ↑v ↑w
hq : q = trinomial k m' n ↑u ↑v ↑w
f : ℤ[X] → ℤ[X] :=
  fun p ↦
    { toFinsupp := AddMonoidAlgebra.ofCoeff (Finsupp.filter (fun x ↦ x ∈ Set.Ioo (k + n) (n + n)) p.toFinsupp.coeff) }
h : C ↑u * X ^ (m + n) + C ↑w * X ^ (n - m + k + n) = C ↑u * X ^ (m' + n) + C ↑w * X ^ (n - m' + k + n)
⊢ q = p ∨ q = p.mirror
Module: Mathlib.Algebra.Polynomial.RuleOfSigns

Goal state before:
pp: R : Type u_1
inst✝² : Ring R
inst✝¹ : LinearOrder R
inst✝ : IsStrictOrderedRing R
P : R[X]
η : R
h₁ : 0 < P.leadingCoeff
h₃ : P ≠ 0
h₄ : P.eraseLead.natDegree + 1 = P.natDegree
h₅ : X - C η ≠ 0
h₆ : P.eraseLead ≠ 0
d : ℕ
hd : P.natDegree = 0 + d + 1
h₂ : P.eraseLead.leadingCoeff = P.nextCoeff
n : ℕ
h_cons :
  ((X - C η) * P.eraseLead).coeffList =
    ((X - C η) * P.eraseLead).leadingCoeff :: (List.replicate n 0 ++ ((X - C η) * P.eraseLead).eraseLead.coeffList)
⊢ ((X - C η) * P).natDegree = P.natDegree + 1

Tactic:
rw [natDegree_mul h₅ h₃, natDegree_X_sub_C, add_comm]

Goal state after:
Module: Mathlib.Algebra.Polynomial.PartialFractions

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
ι : Type u_2
inst✝ : DecidableEq ι
s : Finset ι
g : ι → R[X]
hg : ∀ i ∈ s, (g i).Monic
hgg : (↑s).Pairwise fun i j ↦ IsCoprime (g i) (g j)
q₁ q₂ : R[X]
r₁ r₂ : ι → R[X]
hr₁ : ∀ i ∈ s, (r₁ i).degree < (g i).degree
hr₂ : ∀ i ∈ s, (r₂ i).degree < (g i).degree
hf : q₁ * ∏ i ∈ s, g i + ∑ i ∈ s, r₁ i * ∏ k ∈ s.erase i, g k = q₂ * ∏ i ∈ s, g i + ∑ i ∈ s, r₂ i * ∏ k ∈ s.erase i, g k
⊢ q₁ = q₂ ∧ ∀ i ∈ s, r₁ i = r₂ i

Tactic:
induction s using Finset.cons_induction with

Goal state after:
Module: Mathlib.Algebra.QuadraticAlgebra.Defs

Goal state before:
pp: case mpr
R : Type u_1
a b : R
inst✝ : CommSemiring R
r : R
z : QuadraticAlgebra R a b
⊢ r ∣ z.re ∧ r ∣ z.im → (algebraMap R (QuadraticAlgebra R a b)) r ∣ z

Tactic:
rintro ⟨⟨r, hr⟩, ⟨i, hi⟩⟩

Goal state after:
case mpr
R : Type u_1
a b : R
inst✝ : CommSemiring R
r✝ : R
z : QuadraticAlgebra R a b
r : R
hr : z.re = r✝ * r
i : R
hi : z.im = r✝ * i
⊢ (algebraMap R (QuadraticAlgebra R a b)) r✝ ∣ z
Module: Mathlib.Algebra.QuadraticAlgebra.Basic

Goal state before:
pp: R : Type u_2
a b : R
inst✝ : CommRing R
x : QuadraticAlgebra R a b
⊢ IsUnit x ↔ IsUnit (norm x)

Tactic:
constructor
  · exact IsUnit.map norm
  · simp only [isUnit_iff_exists]
    rintro ⟨r, hr, hr'⟩
    rw [← C_inj (R := R) (a := a) (b := b), C_mul, C_eq_algebraMap, algebraMap_norm_eq_mul_star,
      mul_assoc, map_one] at hr
    refine ⟨_, hr, ?_⟩
    rw [mul_comm, hr]

Goal state after:
Module: Mathlib.Algebra.QuadraticAlgebra.Basic

Goal state before:
pp: R : Type u_2
a b : R
inst✝ : CommRing R
z : QuadraticAlgebra R a b
⊢ norm z = 1 ↔ z ∈ unitary (QuadraticAlgebra R a b)

Tactic:
rw [Unitary.mem_iff_self_mul_star, ← algebraMap_norm_eq_mul_star]
  simp [← algebraMap_inj (R := R) (a := a) (b := b)]

Goal state after:
Module: Mathlib.Algebra.Polynomial.RuleOfSigns

Goal state before:
pp: R : Type u_1
inst✝² : Ring R
inst✝¹ : LinearOrder R
inst✝ : IsStrictOrderedRing R
η : R
hη : 0 < η
P : R[X]
hP : P ≠ 0
h_lC : 0 < P.leadingCoeff
h_mul : (X - C η) * P ≠ 0
h_deg_mul : ((X - C η) * P).natDegree = P.natDegree + 1
d : ℕ
ih : P.eraseLead.signVariations + 1 ≤ ((X - C η) * P.eraseLead).signVariations
hd : P.natDegree = d + 1
s_nC_mul : SignType
hs_nC_mul : SignType.sign ((X - C η) * P).nextCoeff = s_nC_mul
h_ih : P.eraseLead.natDegree < d + 1
h_mul_lC : SignType.sign ((X - C η) * P).leadingCoeff = 1
h_ηP : 0 < η * P.coeff (d + 1)
hs_nC : SignType.sign P.nextCoeff = 1
h₁ : P.nextCoeff ≠ 0
⊢ ?succ.inr.inr.refine_1 = 0

Tactic:
exact rfl

Goal state after:
Module: Mathlib.Algebra.Polynomial.RuleOfSigns

Goal state before:
pp: R : Type u_1
inst✝² : Ring R
inst✝¹ : LinearOrder R
inst✝ : IsStrictOrderedRing R
η : R
hη : 0 < η
P : R[X]
hP : P ≠ 0
h_lC : 0 < P.leadingCoeff
h_mul : (X - C η) * P ≠ 0
h_deg_mul : ((X - C η) * P).natDegree = P.natDegree + 1
d : ℕ
ih : P.eraseLead.signVariations + 1 ≤ ((X - C η) * P.eraseLead).signVariations
hd : P.natDegree = d + 1
s_nC_mul : SignType
hs_nC_mul : SignType.sign ((X - C η) * P).nextCoeff = s_nC_mul
h_ih : P.eraseLead.natDegree < d + 1
h_mul_lC : SignType.sign ((X - C η) * P).leadingCoeff = 1
h_ηP : 0 < η * P.coeff (d + 1)
hs_nC : SignType.sign P.nextCoeff = -1
h₁ : P.nextCoeff ≠ 0
⊢ 1 = ?succ.inl.refine_1

Tactic:
exact rfl

Goal state after:
Module: Mathlib.Algebra.Quandle

Goal state before:
pp: case mul
R : Type u_1
inst✝¹ : Rack R
G : Type u_2
inst✝ : Group G
F : EnvelGroup R →* G
x✝ : EnvelGroup R
x y : PreEnvelGroup R
ih_x :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦x⟧ =
    F ⟦x⟧
ih_y :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦y⟧ =
    F ⟦y⟧
hm : ⟦x.mul y⟧ = Mul.mul ⟦x⟧ ⟦y⟧
⊢ ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦x.mul y⟧ =
    F ⟦x.mul y⟧

Tactic:
simp only [MonoidHom.coe_mk, OneHom.coe_mk, Quotient.lift_mk]

Goal state after:
case mul
R : Type u_1
inst✝¹ : Rack R
G : Type u_2
inst✝ : Group G
F : EnvelGroup R →* G
x✝ : EnvelGroup R
x y : PreEnvelGroup R
ih_x :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦x⟧ =
    F ⟦x⟧
ih_y :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦y⟧ =
    F ⟦y⟧
hm : ⟦x.mul y⟧ = Mul.mul ⟦x⟧ ⟦y⟧
⊢ mapAux ((Quandle.Conj.map F).comp (toEnvelGroup R)) (x.mul y) = F ⟦x.mul y⟧
Module: Mathlib.Algebra.Quandle

Goal state before:
pp: case mul
R : Type u_1
inst✝¹ : Rack R
G : Type u_2
inst✝ : Group G
F : EnvelGroup R →* G
x✝ : EnvelGroup R
x y : PreEnvelGroup R
ih_x :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦x⟧ =
    F ⟦x⟧
ih_y :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦y⟧ =
    F ⟦y⟧
hm : ⟦x.mul y⟧ = Mul.mul ⟦x⟧ ⟦y⟧
⊢ mapAux ((Quandle.Conj.map F).comp (toEnvelGroup R)) (x.mul y) = F ⟦x.mul y⟧

Tactic:
suffices ∀ x y, F (Mul.mul x y) = F (x) * F (y) by
            simp_all only [MonoidHom.coe_mk, OneHom.coe_mk, Quotient.lift_mk]
            rw [← ih_x, ← ih_y, mapAux]

Goal state after:
case mul
R : Type u_1
inst✝¹ : Rack R
G : Type u_2
inst✝ : Group G
F : EnvelGroup R →* G
x✝ : EnvelGroup R
x y : PreEnvelGroup R
ih_x :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦x⟧ =
    F ⟦x⟧
ih_y :
  ((fun f ↦ { toFun := fun x ↦ Quotient.liftOn x (mapAux f) ⋯, map_one' := ⋯, map_mul' := ⋯ })
        ((fun F ↦ (Quandle.Conj.map F).comp (toEnvelGroup R)) F))
      ⟦y⟧ =
    F ⟦y⟧
hm : ⟦x.mul y⟧ = Mul.mul ⟦x⟧ ⟦y⟧
⊢ ∀ (x y : EnvelGroup R), F (Mul.mul x y) = F x * F y
Module: Mathlib.Algebra.QuaternionBasis

Goal state before:
pp: case a
R : Type u_1
A : Type u_2
inst✝² : CommRing R
inst✝¹ : Ring A
inst✝ : Algebra R A
c₁ c₂ c₃ : R
B : Basis A c₁ c₂ c₃
⊢ B.liftHom.range ≤ R[B.i, B.j, B.k]

Tactic:
rintro x ⟨y, rfl⟩

Goal state after:
case a
R : Type u_1
A : Type u_2
inst✝² : CommRing R
inst✝¹ : Ring A
inst✝ : Algebra R A
c₁ c₂ c₃ : R
B : Basis A c₁ c₂ c₃
y : ℍ[R,c₁,c₂,c₃]
⊢ B.liftHom.toRingHom y ∈ R[B.i, B.j, B.k]
Module: Mathlib.Algebra.Ring.CentroidHom

Goal state before:
pp: case refine_2
α : Type u_5
inst✝ : NonUnitalNonAssocSemiring α
T : AddMonoid.End α
h : T ∈ Subsemiring.centralizer (Set.range ⇑L ∪ Set.range ⇑R)
⊢ T ∈ (toEndRingHom α).rangeS

Tactic:
rw [Subsemiring.mem_centralizer_iff] at h
    refine ⟨⟨T, fun a b ↦ ?_, fun a b ↦ ?_⟩, rfl⟩
    · exact congr($(h (L a) (.inl ⟨a, rfl⟩)) b).symm
    · exact congr($(h (R b) (.inr ⟨b, rfl⟩)) a).symm

Goal state after:
Module: Mathlib.Algebra.Ring.CentroidHom

Goal state before:
pp: F : Type u_1
M : Type u_2
N : Type u_3
R✝ : Type u_4
α : Type u_5
inst✝¹⁶ : NonUnitalNonAssocSemiring α
inst✝¹⁵ : Monoid M
inst✝¹⁴ : Monoid N
inst✝¹³ : Semiring R✝
inst✝¹² : DistribMulAction M α
inst✝¹¹ : SMulCommClass M α α
inst✝¹⁰ : IsScalarTower M α α
inst✝⁹ : DistribMulAction N α
inst✝⁸ : SMulCommClass N α α
inst✝⁷ : IsScalarTower N α α
inst✝⁶ : Module R✝ α
inst✝⁵ : SMulCommClass R✝ α α
inst✝⁴ : IsScalarTower R✝ α α
R : Type u_6
inst✝³ : CommSemiring «R»
inst✝² : Module «R» α
inst✝¹ : SMulCommClass «R» α α
inst✝ : IsScalarTower «R» α α
⊢ ⟨{ toAddMonoidHom := 0, map_mul_left' := ⋯, map_mul_right' := ⋯ }, ⋯⟩ = 0

Tactic:
exact rfl

Goal state after:
Module: Mathlib.Algebra.SkewMonoidAlgebra.Lift

Goal state before:
pp: k : Type u_1
G : Type u_2
H : Type u_3
inst✝ : AddCommMonoid k
f : G ≃ H
a : G
b : k
⊢ Finsupp.equivMapDomain f (Finsupp.single a b) = Finsupp.single (f a) b

Tactic:
Finsupp.equivMapDomain_single

Goal state after:
Module: Mathlib.Algebra.Star.CentroidHom

Goal state before:
pp: α : Type u_1
inst✝¹ : NonUnitalNonAssocSemiring α
inst✝ : StarRing α
z : ↥(NonUnitalStarSubsemiring.center α)
a : α
⊢ star (star a) * ↑(star z) = a * ↑(star z)

Tactic:
rw [star_star]

Goal state after:
Module: Mathlib.Algebra.SkewPolynomial.Basic

Goal state before:
pp: R : Type u_1
inst✝¹ : Semiring R
inst✝ : MulSemiringAction (Multiplicative ℕ) R
n : ℕ
r : R
⊢ X * (monomial n) r = (monomial (n + 1)) (φ r)

Tactic:
by
  simp [X_mul]

Goal state after:
Module: Mathlib.Algebra.SkewMonoidAlgebra.Basic

Goal state before:
pp: case single
k : Type u_1
G : Type u_2
inst✝² : Semiring k
inst✝¹ : Monoid G
inst✝ : MulSemiringAction G k
g : G
a : k
⊢ 1 * single g a = single g a

Tactic:
rw [one_def, mul_def, sum_single_index] <;> simp

Goal state after:
Module: Mathlib.Algebra.SkewMonoidAlgebra.Basic

Goal state before:
pp: k : Type u_1
G : Type u_2
inst✝² : Semiring k
inst✝¹ : Mul G
inst✝ : SMulZeroClass G k
f g : SkewMonoidAlgebra k G
x : G
s : Finset (G × G)
hs : ∀ {p : G × G}, p ∈ s ↔ p.1 * p.2 = x
⊢ (f * g).coeff x = ∑ p ∈ s, f.coeff p.1 * p.1 • g.coeff p.2

Tactic:
let F : G × G → k := fun p ↦ if p.1 * p.2 = x then f.coeff p.1 * p.1 • g.coeff p.2 else 0
  calc
    (f * g).coeff x = ∑ a₁ ∈ f.support, ∑ a₂ ∈ g.support, F (a₁, a₂) := coeff_mul f g x
    _ = ∑ p ∈ f.support ×ˢ g.support, F p := by rw [Finset.sum_product]
    _ = ∑ p ∈ (f.support ×ˢ g.support).filter fun p : G × G ↦ p.1 * p.2 = x,
      f.coeff p.1 * p.1 • g.coeff p.2 := (Finset.sum_filter _ _).symm
    _ = ∑ p ∈ s.filter fun p : G × G ↦ p.1 ∈ f.support ∧ p.2 ∈ g.support,
      f.coeff p.1 * p.1 • g.coeff p.2 :=
      (Finset.sum_congr (by ext; simp [Finset.mem_filter, Finset.mem_product, hs, and_comm])
        fun _ _ ↦ rfl)
    _ = ∑ p ∈ s, f.coeff p.1 * p.1 • g.coeff p.2 :=
      Finset.sum_subset (Finset.filter_subset _ _) fun p hps hp ↦ by
        simp only [Finset.mem_filter, mem_support_iff, not_and, Classical.not_not] at hp ⊢
        by_cases h1 : f.coeff p.1 = 0 <;> simp_all

Goal state after: