Module: Mathlib.RingTheory.Polynomial.GaussNorm

Goal state before:
pp: case e'_3
c✝ : ℝ
R✝ : Type u_3
inst✝¹ : Ring R✝
v✝ : AbsoluteValue R✝ ℝ
c : ℝ
R : Type u_3
inst✝ : Ring R
v : AbsoluteValue R ℝ
hna : IsNonarchimedean ⇑v
hc : 0 < c
p q : R[X]
hc0 : 0 ≤ c
i : ℕ
hi_p : gaussNorm v c p = v (p.coeff i) * c ^ i
hlt_p : ∀ j < i, v (p.coeff j) * c ^ j < gaussNorm v c p
j : ℕ
hj_q : gaussNorm v c q = v (q.coeff j) * c ^ j
hlt_q : ∀ j_1 < j, v (q.coeff j_1) * c ^ j_1 < gaussNorm v c q
hvpq : v (p.coeff i) ≠ 0 ∧ v (q.coeff j) ≠ 0
this✝¹ : v (p.coeff i) ≠ 0
this✝ : v (q.coeff j) ≠ 0
x : ℕ
hx : x ∈ range (i + j).succ
hneq : x ≠ i
this : x + (i + j - x) = i + j
⊢ v (p.coeff (x, i + j - x).1 * q.coeff (x, i + j - x).2) * c ^ (i + j) =
    v (p.coeff x) * c ^ x * (v (q.coeff (i + j - x)) * c ^ (i + j - x))

pp: case e'_4
c✝ : ℝ
R✝ : Type u_3
inst✝¹ : Ring R✝
v✝ : AbsoluteValue R✝ ℝ
c : ℝ
R : Type u_3
inst✝ : Ring R
v : AbsoluteValue R ℝ
hna : IsNonarchimedean ⇑v
hc : 0 < c
p q : R[X]
hc0 : 0 ≤ c
i : ℕ
hi_p : gaussNorm v c p = v (p.coeff i) * c ^ i
hlt_p : ∀ j < i, v (p.coeff j) * c ^ j < gaussNorm v c p
j : ℕ
hj_q : gaussNorm v c q = v (q.coeff j) * c ^ j
hlt_q : ∀ j_1 < j, v (q.coeff j_1) * c ^ j_1 < gaussNorm v c q
hvpq : v (p.coeff i) ≠ 0 ∧ v (q.coeff j) ≠ 0
this✝¹ : v (p.coeff i) ≠ 0
this✝ : v (q.coeff j) ≠ 0
x : ℕ
hx : x ∈ range (i + j).succ
hneq : x ≠ i
this : x + (i + j - x) = i + j
⊢ v (p.coeff (i, i + j - i).1 * q.coeff (i, i + j - i).2) * c ^ (i + j) =
    v (p.coeff i) * c ^ i * (v (q.coeff j) * c ^ j)

pp: c✝ : ℝ
R✝ : Type u_3
inst✝¹ : Ring R✝
v✝ : AbsoluteValue R✝ ℝ
c : ℝ
R : Type u_3
inst✝ : Ring R
v : AbsoluteValue R ℝ
hna : IsNonarchimedean ⇑v
hc : 0 < c
p q : R[X]
hc0 : 0 ≤ c
i : ℕ
hi_p : gaussNorm v c p = v (p.coeff i) * c ^ i
hlt_p : ∀ j < i, v (p.coeff j) * c ^ j < gaussNorm v c p
j : ℕ
hj_q : gaussNorm v c q = v (q.coeff j) * c ^ j
hlt_q : ∀ j_1 < j, v (q.coeff j_1) * c ^ j_1 < gaussNorm v c q
hvpq : v (p.coeff i) ≠ 0 ∧ v (q.coeff j) ≠ 0
this✝¹ : v (p.coeff i) ≠ 0
this✝ : v (q.coeff j) ≠ 0
x : ℕ
hx : x ∈ range (i + j).succ
hneq : x ≠ i
this : x + (i + j - x) = i + j
⊢ v (p.coeff x) * c ^ x * (v (q.coeff (i + j - x)) * c ^ (i + j - x)) < v (p.coeff i) * c ^ i * (v (q.coeff j) * c ^ j)

Tactic:
· grind

Goal state after:
case e'_4
c✝ : ℝ
R✝ : Type u_3
inst✝¹ : Ring R✝
v✝ : AbsoluteValue R✝ ℝ
c : ℝ
R : Type u_3
inst✝ : Ring R
v : AbsoluteValue R ℝ
hna : IsNonarchimedean ⇑v
hc : 0 < c
p q : R[X]
hc0 : 0 ≤ c
i : ℕ
hi_p : gaussNorm v c p = v (p.coeff i) * c ^ i
hlt_p : ∀ j < i, v (p.coeff j) * c ^ j < gaussNorm v c p
j : ℕ
hj_q : gaussNorm v c q = v (q.coeff j) * c ^ j
hlt_q : ∀ j_1 < j, v (q.coeff j_1) * c ^ j_1 < gaussNorm v c q
hvpq : v (p.coeff i) ≠ 0 ∧ v (q.coeff j) ≠ 0
this✝¹ : v (p.coeff i) ≠ 0
this✝ : v (q.coeff j) ≠ 0
x : ℕ
hx : x ∈ range (i + j).succ
hneq : x ≠ i
this : x + (i + j - x) = i + j
⊢ v (p.coeff (i, i + j - i).1 * q.coeff (i, i + j - i).2) * c ^ (i + j) =
    v (p.coeff i) * c ^ i * (v (q.coeff j) * c ^ j)

c✝ : ℝ
R✝ : Type u_3
inst✝¹ : Ring R✝
v✝ : AbsoluteValue R✝ ℝ
c : ℝ
R : Type u_3
inst✝ : Ring R
v : AbsoluteValue R ℝ
hna : IsNonarchimedean ⇑v
hc : 0 < c
p q : R[X]
hc0 : 0 ≤ c
i : ℕ
hi_p : gaussNorm v c p = v (p.coeff i) * c ^ i
hlt_p : ∀ j < i, v (p.coeff j) * c ^ j < gaussNorm v c p
j : ℕ
hj_q : gaussNorm v c q = v (q.coeff j) * c ^ j
hlt_q : ∀ j_1 < j, v (q.coeff j_1) * c ^ j_1 < gaussNorm v c q
hvpq : v (p.coeff i) ≠ 0 ∧ v (q.coeff j) ≠ 0
this✝¹ : v (p.coeff i) ≠ 0
this✝ : v (q.coeff j) ≠ 0
x : ℕ
hx : x ∈ range (i + j).succ
hneq : x ≠ i
this : x + (i + j - x) = i + j
⊢ v (p.coeff x) * c ^ x * (v (q.coeff (i + j - x)) * c ^ (i + j - x)) < v (p.coeff i) * c ^ i * (v (q.coeff j) * c ^ j)