Module: Mathlib.Combinatorics.Enumerative.Partition.GenFun

Goal state before:
pp: case refine_1
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : T2Space R
f : ℕ → ℕ → R
d : ℕ
s : Finset ℕ
hs0 : 0 ∉ s
g : ℕ →₀ ℕ
hg : g ∈ s.finsuppAntidiag d
hprod : ∀ i ∈ s, (coeff (g i)) (1 + ∑' (j : ℕ), f i (j + 1) • X ^ (i * (j + 1))) ≠ 0
hgne0 : ∀ (i : ℕ), g i ≠ 0 ↔ i ≠ 0 ∧ i ≤ g i
⊢ ∀ (a : ℕ), a ∈ g.support ↔ g a / a ≠ 0

pp: case refine_2
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : T2Space R
f : ℕ → ℕ → R
d : ℕ
s : Finset ℕ
hs0 : 0 ∉ s
g : ℕ →₀ ℕ
hg : g ∈ s.finsuppAntidiag d
hprod : ∀ i ∈ s, (coeff (g i)) (1 + ∑' (j : ℕ), f i (j + 1) • X ^ (i * (j + 1))) ≠ 0
hgne0 : ∀ (i : ℕ), g i ≠ 0 ↔ i ≠ 0 ∧ i ≤ g i
⊢ ∀ {i : ℕ},
    i ∈ Finsupp.toMultiset { support := g.support, toFun := fun i ↦ g i / i, mem_support_toFun := ?refine_1 } → 0 < i

pp: case refine_3
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : T2Space R
f : ℕ → ℕ → R
d : ℕ
s : Finset ℕ
hs0 : 0 ∉ s
g : ℕ →₀ ℕ
hg : g ∈ s.finsuppAntidiag d
hprod : ∀ i ∈ s, (coeff (g i)) (1 + ∑' (j : ℕ), f i (j + 1) • X ^ (i * (j + 1))) ≠ 0
hgne0 : ∀ (i : ℕ), g i ≠ 0 ↔ i ≠ 0 ∧ i ≤ g i
⊢ (Finsupp.toMultiset { support := g.support, toFun := fun i ↦ g i / i, mem_support_toFun := ?refine_1 }).sum = d

pp: case refine_4
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : T2Space R
f : ℕ → ℕ → R
d : ℕ
s : Finset ℕ
hs0 : 0 ∉ s
g : ℕ →₀ ℕ
hg : g ∈ s.finsuppAntidiag d
hprod : ∀ i ∈ s, (coeff (g i)) (1 + ∑' (j : ℕ), f i (j + 1) • X ^ (i * (j + 1))) ≠ 0
hgne0 : ∀ (i : ℕ), g i ≠ 0 ↔ i ≠ 0 ∧ i ≤ g i
⊢ { parts := Finsupp.toMultiset { support := g.support, toFun := fun i ↦ g i / i, mem_support_toFun := ?refine_1 },
        parts_pos := ?refine_2, parts_sum := ?refine_3 }.toFinsuppAntidiag =
    g

Tactic:
· simpa using hgne0

Goal state after:
case refine_2
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : T2Space R
f : ℕ → ℕ → R
d : ℕ
s : Finset ℕ
hs0 : 0 ∉ s
g : ℕ →₀ ℕ
hg : g ∈ s.finsuppAntidiag d
hprod : ∀ i ∈ s, (coeff (g i)) (1 + ∑' (j : ℕ), f i (j + 1) • X ^ (i * (j + 1))) ≠ 0
hgne0 : ∀ (i : ℕ), g i ≠ 0 ↔ i ≠ 0 ∧ i ≤ g i
⊢ ∀ {i : ℕ}, i ∈ Finsupp.toMultiset { support := g.support, toFun := fun i ↦ g i / i, mem_support_toFun := ⋯ } → 0 < i

case refine_3
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : T2Space R
f : ℕ → ℕ → R
d : ℕ
s : Finset ℕ
hs0 : 0 ∉ s
g : ℕ →₀ ℕ
hg : g ∈ s.finsuppAntidiag d
hprod : ∀ i ∈ s, (coeff (g i)) (1 + ∑' (j : ℕ), f i (j + 1) • X ^ (i * (j + 1))) ≠ 0
hgne0 : ∀ (i : ℕ), g i ≠ 0 ↔ i ≠ 0 ∧ i ≤ g i
⊢ (Finsupp.toMultiset { support := g.support, toFun := fun i ↦ g i / i, mem_support_toFun := ⋯ }).sum = d

case refine_4
R : Type u_1
inst✝² : CommSemiring R
inst✝¹ : TopologicalSpace R
inst✝ : T2Space R
f : ℕ → ℕ → R
d : ℕ
s : Finset ℕ
hs0 : 0 ∉ s
g : ℕ →₀ ℕ
hg : g ∈ s.finsuppAntidiag d
hprod : ∀ i ∈ s, (coeff (g i)) (1 + ∑' (j : ℕ), f i (j + 1) • X ^ (i * (j + 1))) ≠ 0
hgne0 : ∀ (i : ℕ), g i ≠ 0 ↔ i ≠ 0 ∧ i ≤ g i
⊢ { parts := Finsupp.toMultiset { support := g.support, toFun := fun i ↦ g i / i, mem_support_toFun := ⋯ },
        parts_pos := ?refine_2, parts_sum := ?refine_3 }.toFinsuppAntidiag =
    g