l3lab/ntp-mathlib huggingface dataset:
/-- Bijection obtained by separating the term of index `none` of a dfinsupp over `Option ι`.

This is the dfinsupp version of `Equiv.piOptionEquivProd`. -/
@[simps]
noncomputable def equivProdDFinsupp [∀ i, Zero (α i)] : (Π₀ i, α i) ≃ α none × Π₀ i, α (some i)
    where
  toFun f := (f none, comapDomain some (Option.some_injective _) f)
  invFun f := f.2.extendWith f.1
  left_inv f := by
    ext i; cases' i with i
    · rw [extendWith_none]
    · 

Proof state:
case h.some
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
κ : Type u_1
α : Option ι → Type v
inst✝ : (i : Option ι) → Zero (α i)
f : Π₀ (i : Option ι), α i
i : ι
⊢ ((fun f => extendWith f.1 f.2) ((fun f => (f none, comapDomain some (_ : Function.Injective some) f)) f)) (some i) =
    f (some i)

Next tactic:
rw [extendWith_some, comapDomain_apply]
/-- Bijection obtained by separating the term of index `none` of a dfinsupp over `Option ι`.

This is the dfinsupp version of `Equiv.piOptionEquivProd`. -/
@[simps]
noncomputable def equivProdDFinsupp [∀ i, Zero (α i)] : (Π₀ i, α i) ≃ α none × Π₀ i, α (some i)
    where
  toFun f := (f none, comapDomain some (Option.some_injective _) f)
  invFun f := f.2.extendWith f.1
  left_inv f := by
    ext i; cases' i with i
    · rw [extendWith_none]
    · rw [extendWith_some, comapDomain_apply]
  right_inv x := by
    

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
κ : Type u_1
α : Option ι → Type v
inst✝ : (i : Option ι) → Zero (α i)
x : α none × Π₀ (i : ι), α (some i)
⊢ (fun f => (f none, comapDomain some (_ : Function.Injective some) f)) ((fun f => extendWith f.1 f.2) x) = x

Next tactic:
dsimp only
/-- Bijection obtained by separating the term of index `none` of a dfinsupp over `Option ι`.

This is the dfinsupp version of `Equiv.piOptionEquivProd`. -/
@[simps]
noncomputable def equivProdDFinsupp [∀ i, Zero (α i)] : (Π₀ i, α i) ≃ α none × Π₀ i, α (some i)
    where
  toFun f := (f none, comapDomain some (Option.some_injective _) f)
  invFun f := f.2.extendWith f.1
  left_inv f := by
    ext i; cases' i with i
    · rw [extendWith_none]
    · rw [extendWith_some, comapDomain_apply]
  right_inv x := by
    dsimp only
    

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
κ : Type u_1
α : Option ι → Type v
inst✝ : (i : Option ι) → Zero (α i)
x : α none × Π₀ (i : ι), α (some i)
⊢ ((extendWith x.1 x.2) none, comapDomain some (_ : Function.Injective some) (extendWith x.1 x.2)) = x

Next tactic:
ext
/-- Bijection obtained by separating the term of index `none` of a dfinsupp over `Option ι`.

This is the dfinsupp version of `Equiv.piOptionEquivProd`. -/
@[simps]
noncomputable def equivProdDFinsupp [∀ i, Zero (α i)] : (Π₀ i, α i) ≃ α none × Π₀ i, α (some i)
    where
  toFun f := (f none, comapDomain some (Option.some_injective _) f)
  invFun f := f.2.extendWith f.1
  left_inv f := by
    ext i; cases' i with i
    · rw [extendWith_none]
    · rw [extendWith_some, comapDomain_apply]
  right_inv x := by
    dsimp only
    ext
    · 

Proof state:
case a
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
κ : Type u_1
α : Option ι → Type v
inst✝ : (i : Option ι) → Zero (α i)
x : α none × Π₀ (i : ι), α (some i)
⊢ ((extendWith x.1 x.2) none, comapDomain some (_ : Function.Injective some) (extendWith x.1 x.2)).1 = x.1

Next tactic:
exact extendWith_none x.snd _
/-- Bijection obtained by separating the term of index `none` of a dfinsupp over `Option ι`.

This is the dfinsupp version of `Equiv.piOptionEquivProd`. -/
@[simps]
noncomputable def equivProdDFinsupp [∀ i, Zero (α i)] : (Π₀ i, α i) ≃ α none × Π₀ i, α (some i)
    where
  toFun f := (f none, comapDomain some (Option.some_injective _) f)
  invFun f := f.2.extendWith f.1
  left_inv f := by
    ext i; cases' i with i
    · rw [extendWith_none]
    · rw [extendWith_some, comapDomain_apply]
  right_inv x := by
    dsimp only
    ext
    · exact extendWith_none x.snd _
    · 

Proof state:
case a.h
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
κ : Type u_1
α : Option ι → Type v
inst✝ : (i : Option ι) → Zero (α i)
x : α none × Π₀ (i : ι), α (some i)
i✝ : ι
⊢ ((extendWith x.1 x.2) none, comapDomain some (_ : Function.Injective some) (extendWith x.1 x.2)).2 i✝ = x.2 i✝

Next tactic:
rw [comapDomain_apply, extendWith_some]
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
⊢ prod (mapRange f hf g) h = prod g fun i b => h i (f i b)

Next tactic:
rw [mapRange_def]
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
⊢ prod (mk (support g) fun i => f (↑i) (g ↑i)) h = prod g fun i b => h i (f i b)

Next tactic:
refine' (Finset.prod_subset support_mk_subset _).trans _
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · 

Proof state:
case refine'_1
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
⊢ ∀ x ∈ support g,
    x ∉ support (mk (support g) fun i => f (↑i) (g ↑i)) → h x ((mk (support g) fun i => f (↑i) (g ↑i)) x) = 1

Next tactic:
intro i h1 h2
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · intro i h1 h2
    

Proof state:
case refine'_1
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
i : ι
h1 : i ∈ support g
h2 : i ∉ support (mk (support g) fun i => f (↑i) (g ↑i))
⊢ h i ((mk (support g) fun i => f (↑i) (g ↑i)) i) = 1

Next tactic:
simp only [mem_support_toFun, ne_eq] at h1
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · intro i h1 h2
    simp only [mem_support_toFun, ne_eq] at h1
    

Proof state:
case refine'_1
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
i : ι
h2 : i ∉ support (mk (support g) fun i => f (↑i) (g ↑i))
h1 : ¬g i = 0
⊢ h i ((mk (support g) fun i => f (↑i) (g ↑i)) i) = 1

Next tactic:
simp only [Finset.coe_sort_coe, mem_support_toFun, mk_apply, ne_eq, h1, not_false_iff,
      dite_eq_ite, ite_true, not_not] at h2
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · intro i h1 h2
    simp only [mem_support_toFun, ne_eq] at h1
    simp only [Finset.coe_sort_coe, mem_support_toFun, mk_apply, ne_eq, h1, not_false_iff,
      dite_eq_ite, ite_true, not_not] at h2
    

Proof state:
case refine'_1
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
i : ι
h1 : ¬g i = 0
h2 : f i (g i) = 0
⊢ h i ((mk (support g) fun i => f (↑i) (g ↑i)) i) = 1

Next tactic:
simp [h2, h0]
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · intro i h1 h2
    simp only [mem_support_toFun, ne_eq] at h1
    simp only [Finset.coe_sort_coe, mem_support_toFun, mk_apply, ne_eq, h1, not_false_iff,
      dite_eq_ite, ite_true, not_not] at h2
    simp [h2, h0]
  · 

Proof state:
case refine'_2
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
⊢ ∏ x in support g, h x ((mk (support g) fun i => f (↑i) (g ↑i)) x) = prod g fun i b => h i (f i b)

Next tactic:
refine' Finset.prod_congr rfl _
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · intro i h1 h2
    simp only [mem_support_toFun, ne_eq] at h1
    simp only [Finset.coe_sort_coe, mem_support_toFun, mk_apply, ne_eq, h1, not_false_iff,
      dite_eq_ite, ite_true, not_not] at h2
    simp [h2, h0]
  · refine' Finset.prod_congr rfl _
    

Proof state:
case refine'_2
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
⊢ ∀ x ∈ support g, h x ((mk (support g) fun i => f (↑i) (g ↑i)) x) = (fun i b => h i (f i b)) x (g x)

Next tactic:
intro i h1
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · intro i h1 h2
    simp only [mem_support_toFun, ne_eq] at h1
    simp only [Finset.coe_sort_coe, mem_support_toFun, mk_apply, ne_eq, h1, not_false_iff,
      dite_eq_ite, ite_true, not_not] at h2
    simp [h2, h0]
  · refine' Finset.prod_congr rfl _
    intro i h1
    

Proof state:
case refine'_2
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
i : ι
h1 : i ∈ support g
⊢ h i ((mk (support g) fun i => f (↑i) (g ↑i)) i) = (fun i b => h i (f i b)) i (g i)

Next tactic:
simp only [mem_support_toFun, ne_eq] at h1
@[to_additive]
theorem prod_mapRange_index {β₁ : ι → Type v₁} {β₂ : ι → Type v₂} [∀ i, Zero (β₁ i)]
    [∀ i, Zero (β₂ i)] [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ (i) (x : β₂ i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f : ∀ i, β₁ i → β₂ i} {hf : ∀ i, f i 0 = 0} {g : Π₀ i, β₁ i} {h : ∀ i, β₂ i → γ}
    (h0 : ∀ i, h i 0 = 1) : (mapRange f hf g).prod h = g.prod fun i b => h i (f i b) := by
  rw [mapRange_def]
  refine' (Finset.prod_subset support_mk_subset _).trans _
  · intro i h1 h2
    simp only [mem_support_toFun, ne_eq] at h1
    simp only [Finset.coe_sort_coe, mem_support_toFun, mk_apply, ne_eq, h1, not_false_iff,
      dite_eq_ite, ite_true, not_not] at h2
    simp [h2, h0]
  · refine' Finset.prod_congr rfl _
    intro i h1
    simp only [mem_support_toFun, ne_eq] at h1
    

Proof state:
case refine'_2
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂✝ : ι → Type v₂
dec : DecidableEq ι
β₁ : ι → Type v₁
β₂ : ι → Type v₂
inst✝⁴ : (i : ι) → Zero (β₁ i)
inst✝³ : (i : ι) → Zero (β₂ i)
inst✝² : (i : ι) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → (x : β₂ i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f : (i : ι) → β₁ i → β₂ i
hf : ∀ (i : ι), f i 0 = 0
g : Π₀ (i : ι), β₁ i
h : (i : ι) → β₂ i → γ
h0 : ∀ (i : ι), h i 0 = 1
i : ι
h1 : ¬g i = 0
⊢ h i ((mk (support g) fun i => f (↑i) (g ↑i)) i) = (fun i b => h i (f i b)) i (g i)

Next tactic:
simp [h1]
@[to_additive]
theorem prod_single_index [∀ i, Zero (β i)] [∀ (i) (x : β i), Decidable (x ≠ 0)] [CommMonoid γ]
    {i : ι} {b : β i} {h : ∀ i, β i → γ} (h_zero : h i 0 = 1) : (single i b).prod h = h i b := by
  

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
inst✝² : (i : ι) → Zero (β i)
inst✝¹ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
i : ι
b : β i
h : (i : ι) → β i → γ
h_zero : h i 0 = 1
⊢ prod (single i b) h = h i b

Next tactic:
by_cases h : b ≠ 0
@[to_additive]
theorem prod_single_index [∀ i, Zero (β i)] [∀ (i) (x : β i), Decidable (x ≠ 0)] [CommMonoid γ]
    {i : ι} {b : β i} {h : ∀ i, β i → γ} (h_zero : h i 0 = 1) : (single i b).prod h = h i b := by
  by_cases h : b ≠ 0
  · 

Proof state:
case pos
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
inst✝² : (i : ι) → Zero (β i)
inst✝¹ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
i : ι
b : β i
h✝ : (i : ι) → β i → γ
h_zero : h✝ i 0 = 1
h : b ≠ 0
⊢ prod (single i b) h✝ = h✝ i b

Next tactic:
simp [DFinsupp.prod, support_single_ne_zero h]
@[to_additive]
theorem prod_single_index [∀ i, Zero (β i)] [∀ (i) (x : β i), Decidable (x ≠ 0)] [CommMonoid γ]
    {i : ι} {b : β i} {h : ∀ i, β i → γ} (h_zero : h i 0 = 1) : (single i b).prod h = h i b := by
  by_cases h : b ≠ 0
  · simp [DFinsupp.prod, support_single_ne_zero h]
  · 

Proof state:
case neg
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
inst✝² : (i : ι) → Zero (β i)
inst✝¹ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
i : ι
b : β i
h✝ : (i : ι) → β i → γ
h_zero : h✝ i 0 = 1
h : ¬b ≠ 0
⊢ prod (single i b) h✝ = h✝ i b

Next tactic:
rw [not_not] at h
@[to_additive]
theorem prod_single_index [∀ i, Zero (β i)] [∀ (i) (x : β i), Decidable (x ≠ 0)] [CommMonoid γ]
    {i : ι} {b : β i} {h : ∀ i, β i → γ} (h_zero : h i 0 = 1) : (single i b).prod h = h i b := by
  by_cases h : b ≠ 0
  · simp [DFinsupp.prod, support_single_ne_zero h]
  · rw [not_not] at h
    

Proof state:
case neg
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
inst✝² : (i : ι) → Zero (β i)
inst✝¹ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
i : ι
b : β i
h✝ : (i : ι) → β i → γ
h_zero : h✝ i 0 = 1
h : b = 0
⊢ prod (single i b) h✝ = h✝ i b

Next tactic:
simp [h, prod_zero_index, h_zero]
@[to_additive]
theorem prod_single_index [∀ i, Zero (β i)] [∀ (i) (x : β i), Decidable (x ≠ 0)] [CommMonoid γ]
    {i : ι} {b : β i} {h : ∀ i, β i → γ} (h_zero : h i 0 = 1) : (single i b).prod h = h i b := by
  by_cases h : b ≠ 0
  · simp [DFinsupp.prod, support_single_ne_zero h]
  · rw [not_not] at h
    simp [h, prod_zero_index, h_zero]
    

Proof state:
case neg
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
inst✝² : (i : ι) → Zero (β i)
inst✝¹ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
i : ι
b : β i
h✝ : (i : ι) → β i → γ
h_zero : h✝ i 0 = 1
h : b = 0
⊢ prod 0 h✝ = 1

Next tactic:
rfl
theorem support_sum {ι₁ : Type u₁} [DecidableEq ι₁] {β₁ : ι₁ → Type v₁} [∀ i₁, Zero (β₁ i₁)]
    [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ i, AddCommMonoid (β i)]
    [∀ (i) (x : β i), Decidable (x ≠ 0)] {f : Π₀ i₁, β₁ i₁} {g : ∀ i₁, β₁ i₁ → Π₀ i, β i} :
    (f.sum g).support ⊆ f.support.biUnion fun i => (g i (f i)).support := by
  

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
ι₁ : Type u₁
inst✝⁴ : DecidableEq ι₁
β₁ : ι₁ → Type v₁
inst✝³ : (i₁ : ι₁) → Zero (β₁ i₁)
inst✝² : (i : ι₁) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → AddCommMonoid (β i)
inst✝ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
f : Π₀ (i₁ : ι₁), β₁ i₁
g : (i₁ : ι₁) → β₁ i₁ → Π₀ (i : ι), β i
⊢ support (sum f g) ⊆ Finset.biUnion (support f) fun i => support (g i (f i))

Next tactic:
have :
    ∀ i₁ : ι,
      (f.sum fun (i : ι₁) (b : β₁ i) => (g i b) i₁) ≠ 0 → ∃ i : ι₁, f i ≠ 0 ∧ ¬(g i (f i)) i₁ = 0 :=
    fun i₁ h =>
    let ⟨i, hi, Ne⟩ := Finset.exists_ne_zero_of_sum_ne_zero h
    ⟨i, mem_support_iff.1 hi, Ne⟩
theorem support_sum {ι₁ : Type u₁} [DecidableEq ι₁] {β₁ : ι₁ → Type v₁} [∀ i₁, Zero (β₁ i₁)]
    [∀ (i) (x : β₁ i), Decidable (x ≠ 0)] [∀ i, AddCommMonoid (β i)]
    [∀ (i) (x : β i), Decidable (x ≠ 0)] {f : Π₀ i₁, β₁ i₁} {g : ∀ i₁, β₁ i₁ → Π₀ i, β i} :
    (f.sum g).support ⊆ f.support.biUnion fun i => (g i (f i)).support := by
  have :
    ∀ i₁ : ι,
      (f.sum fun (i : ι₁) (b : β₁ i) => (g i b) i₁) ≠ 0 → ∃ i : ι₁, f i ≠ 0 ∧ ¬(g i (f i)) i₁ = 0 :=
    fun i₁ h =>
    let ⟨i, hi, Ne⟩ := Finset.exists_ne_zero_of_sum_ne_zero h
    ⟨i, mem_support_iff.1 hi, Ne⟩
  

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁✝ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
ι₁ : Type u₁
inst✝⁴ : DecidableEq ι₁
β₁ : ι₁ → Type v₁
inst✝³ : (i₁ : ι₁) → Zero (β₁ i₁)
inst✝² : (i : ι₁) → (x : β₁ i) → Decidable (x ≠ 0)
inst✝¹ : (i : ι) → AddCommMonoid (β i)
inst✝ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
f : Π₀ (i₁ : ι₁), β₁ i₁
g : (i₁ : ι₁) → β₁ i₁ → Π₀ (i : ι), β i
this : ∀ (i₁ : ι), (sum f fun i b => (g i b) i₁) ≠ 0 → ∃ i, f i ≠ 0 ∧ ¬(g i (f i)) i₁ = 0
⊢ support (sum f g) ⊆ Finset.biUnion (support f) fun i => support (g i (f i))

Next tactic:
simpa [Finset.subset_iff, mem_support_iff, Finset.mem_biUnion, sum_apply] using this
@[to_additive]
theorem prod_add_index [∀ i, AddCommMonoid (β i)] [∀ (i) (x : β i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f g : Π₀ i, β i} {h : ∀ i, β i → γ} (h_zero : ∀ i, h i 0 = 1)
    (h_add : ∀ i b₁ b₂, h i (b₁ + b₂) = h i b₁ * h i b₂) : (f + g).prod h = f.prod h * g.prod h :=
  have f_eq : (∏ i in f.support ∪ g.support, h i (f i)) = f.prod h :=
    (Finset.prod_subset (Finset.subset_union_left _ _) <| by
        

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
inst✝² : (i : ι) → AddCommMonoid (β i)
inst✝¹ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f g : Π₀ (i : ι), β i
h : (i : ι) → β i → γ
h_zero : ∀ (i : ι), h i 0 = 1
h_add : ∀ (i : ι) (b₁ b₂ : β i), h i (b₁ + b₂) = h i b₁ * h i b₂
⊢ ∀ x ∈ support f ∪ support g, x ∉ support f → h x (f x) = 1

Next tactic:
simp (config := { contextual := true }) [mem_support_iff, h_zero]
@[to_additive]
theorem prod_add_index [∀ i, AddCommMonoid (β i)] [∀ (i) (x : β i), Decidable (x ≠ 0)]
    [CommMonoid γ] {f g : Π₀ i, β i} {h : ∀ i, β i → γ} (h_zero : ∀ i, h i 0 = 1)
    (h_add : ∀ i b₁ b₂, h i (b₁ + b₂) = h i b₁ * h i b₂) : (f + g).prod h = f.prod h * g.prod h :=
  have f_eq : (∏ i in f.support ∪ g.support, h i (f i)) = f.prod h :=
    (Finset.prod_subset (Finset.subset_union_left _ _) <| by
        simp (config := { contextual := true }) [mem_support_iff, h_zero]).symm
  have g_eq : (∏ i in f.support ∪ g.support, h i (g i)) = g.prod h :=
    (Finset.prod_subset (Finset.subset_union_right _ _) <| by
        

Proof state:
ι : Type u
γ : Type w
β : ι → Type v
β₁ : ι → Type v₁
β₂ : ι → Type v₂
dec : DecidableEq ι
inst✝² : (i : ι) → AddCommMonoid (β i)
inst✝¹ : (i : ι) → (x : β i) → Decidable (x ≠ 0)
inst✝ : CommMonoid γ
f g : Π₀ (i : ι), β i
h : (i : ι) → β i → γ
h_zero : ∀ (i : ι), h i 0 = 1
h_add : ∀ (i : ι) (b₁ b₂ : β i), h i (b₁ + b₂) = h i b₁ * h i b₂
f_eq : ∏ i in support f ∪ support g, h i (f i) = prod f h
⊢ ∀ x ∈ support f ∪ support g, x ∉ support g → h x (g x) = 1

Next tactic:
simp (config := { contextual := true }) [mem_support_iff, h_zero]