Module: Mathlib.RingTheory.MvPolynomial.IrreducibleQuadratic

Goal state before:
pp: case hf0
n : Type u_1
R : Type u_2
inst✝¹ : CommRing R
inst✝ : IsDomain R
f : MvPolynomial n R
nontrivial : f.support.Nontrivial
d : n →₀ ℕ
hd : d ∈ f.support
i : n
hdi : d i = 1
disjoint : (↑f.support).PairwiseDisjoint Finsupp.support
isPrimitive : ∀ (r : R), (∀ (d : n →₀ ℕ), r ∣ coeff d f) → IsUnit r
hfd : coeff d f ≠ 0
d₀ : n →₀ ℕ := ⋯
φ : MvPolynomial n R := ⋯
ψ : MvPolynomial n R := ⋯
hf : f = φ * X i + ψ
hφ : φ * X i = (monomial d) (coeff d f)
hdψ : ∀ (k : n →₀ ℕ), coeff k ψ = if d = k then 0 else coeff k f
⊢ φ ≠ 0

pp: case hif
n : Type u_1
R : Type u_2
inst✝¹ : CommRing R
inst✝ : IsDomain R
f : MvPolynomial n R
nontrivial : f.support.Nontrivial
d : n →₀ ℕ
hd : d ∈ f.support
i : n
hdi : d i = 1
disjoint : (↑f.support).PairwiseDisjoint Finsupp.support
isPrimitive : ∀ (r : R), (∀ (d : n →₀ ℕ), r ∣ coeff d f) → IsUnit r
hfd : coeff d f ≠ 0
d₀ : n →₀ ℕ := ⋯
φ : MvPolynomial n R := ⋯
ψ : MvPolynomial n R := ⋯
hf : f = φ * X i + ψ
hφ : φ * X i = (monomial d) (coeff d f)
hdψ : ∀ (k : n →₀ ℕ), coeff k ψ = if d = k then 0 else coeff k f
⊢ i ∉ φ.vars

pp: case hig
n : Type u_1
R : Type u_2
inst✝¹ : CommRing R
inst✝ : IsDomain R
f : MvPolynomial n R
nontrivial : f.support.Nontrivial
d : n →₀ ℕ
hd : d ∈ f.support
i : n
hdi : d i = 1
disjoint : (↑f.support).PairwiseDisjoint Finsupp.support
isPrimitive : ∀ (r : R), (∀ (d : n →₀ ℕ), r ∣ coeff d f) → IsUnit r
hfd : coeff d f ≠ 0
d₀ : n →₀ ℕ := ⋯
φ : MvPolynomial n R := ⋯
ψ : MvPolynomial n R := ⋯
hf : f = φ * X i + ψ
hφ : φ * X i = (monomial d) (coeff d f)
hdψ : ∀ (k : n →₀ ℕ), coeff k ψ = if d = k then 0 else coeff k f
⊢ i ∉ ψ.vars

pp: case h
n : Type u_1
R : Type u_2
inst✝¹ : CommRing R
inst✝ : IsDomain R
f : MvPolynomial n R
nontrivial : f.support.Nontrivial
d : n →₀ ℕ
hd : d ∈ f.support
i : n
hdi : d i = 1
disjoint : (↑f.support).PairwiseDisjoint Finsupp.support
isPrimitive : ∀ (r : R), (∀ (d : n →₀ ℕ), r ∣ coeff d f) → IsUnit r
hfd : coeff d f ≠ 0
d₀ : n →₀ ℕ := ⋯
φ : MvPolynomial n R := ⋯
ψ : MvPolynomial n R := ⋯
hf : f = φ * X i + ψ
hφ : φ * X i = (monomial d) (coeff d f)
hdψ : ∀ (k : n →₀ ℕ), coeff k ψ = if d = k then 0 else coeff k f
⊢ IsRelPrime φ ψ

Tactic:
· grind only [monomial_eq_zero]

Goal state after:
case hif
n : Type u_1
R : Type u_2
inst✝¹ : CommRing R
inst✝ : IsDomain R
f : MvPolynomial n R
nontrivial : f.support.Nontrivial
d : n →₀ ℕ
hd : d ∈ f.support
i : n
hdi : d i = 1
disjoint : (↑f.support).PairwiseDisjoint Finsupp.support
isPrimitive : ∀ (r : R), (∀ (d : n →₀ ℕ), r ∣ coeff d f) → IsUnit r
hfd : coeff d f ≠ 0
d₀ : n →₀ ℕ := ⋯
φ : MvPolynomial n R := ⋯
ψ : MvPolynomial n R := ⋯
hf : f = φ * X i + ψ
hφ : φ * X i = (monomial d) (coeff d f)
hdψ : ∀ (k : n →₀ ℕ), coeff k ψ = if d = k then 0 else coeff k f
⊢ i ∉ φ.vars

case hig
n : Type u_1
R : Type u_2
inst✝¹ : CommRing R
inst✝ : IsDomain R
f : MvPolynomial n R
nontrivial : f.support.Nontrivial
d : n →₀ ℕ
hd : d ∈ f.support
i : n
hdi : d i = 1
disjoint : (↑f.support).PairwiseDisjoint Finsupp.support
isPrimitive : ∀ (r : R), (∀ (d : n →₀ ℕ), r ∣ coeff d f) → IsUnit r
hfd : coeff d f ≠ 0
d₀ : n →₀ ℕ := ⋯
φ : MvPolynomial n R := ⋯
ψ : MvPolynomial n R := ⋯
hf : f = φ * X i + ψ
hφ : φ * X i = (monomial d) (coeff d f)
hdψ : ∀ (k : n →₀ ℕ), coeff k ψ = if d = k then 0 else coeff k f
⊢ i ∉ ψ.vars

case h
n : Type u_1
R : Type u_2
inst✝¹ : CommRing R
inst✝ : IsDomain R
f : MvPolynomial n R
nontrivial : f.support.Nontrivial
d : n →₀ ℕ
hd : d ∈ f.support
i : n
hdi : d i = 1
disjoint : (↑f.support).PairwiseDisjoint Finsupp.support
isPrimitive : ∀ (r : R), (∀ (d : n →₀ ℕ), r ∣ coeff d f) → IsUnit r
hfd : coeff d f ≠ 0
d₀ : n →₀ ℕ := ⋯
φ : MvPolynomial n R := ⋯
ψ : MvPolynomial n R := ⋯
hf : f = φ * X i + ψ
hφ : φ * X i = (monomial d) (coeff d f)
hdψ : ∀ (k : n →₀ ℕ), coeff k ψ = if d = k then 0 else coeff k f
⊢ IsRelPrime φ ψ