have : ∀ {f s p q fs ss : ℕ} (_ : fs ≤ p) (_ : ss ≤ q),
    f + s + (p + q - (fs + ss)) = f + (p - fs) + (s + (q - ss)) := by
  intros f s p q fs ss hP hQ
  zify [add_le_add hP hQ, hP, hQ]
  ring
case neg.e_a.h
R : Type ?u.198757
ι : Type u_2
inst✝² : CommSemiring R
S : Type u_1
inst✝¹ : CommRing S
inst✝ : IsDomain S
i : ι
p q : MvPolynomial ι S
hp : ¬p = 0
hq : ¬q = 0
a : (ι →₀ ℕ) × (ι →₀ ℕ)
ha : a.1 ∈ p.support ∧ a.2 ∈ q.support
j : ι
⊢ a.1 j + a.2 j +
      ((Finsupp.single i p.totalDegree) j + (Finsupp.single i q.totalDegree) j -
        ((Finsupp.single i (a.1.sum fun x m => m)) j + (Finsupp.single i (a.2.sum fun x m => m)) j)) =
    a.1 j + ((Finsupp.single i p.totalDegree) j - (Finsupp.single i (a.1.sum fun x m => m)) j) +
      (a.2 j + ((Finsupp.single i q.totalDegree) j - (Finsupp.single i (a.2.sum fun x m => m)) j))

case neg.e_a.h_zero
R : Type ?u.198757
ι : Type u_2
inst✝² : CommSemiring R
S : Type u_1
inst✝¹ : CommRing S
inst✝ : IsDomain S
i : ι
p q : MvPolynomial ι S
hp : ¬p = 0
hq : ¬q = 0
a : (ι →₀ ℕ) × (ι →₀ ℕ)
ha : a.1 ∈ p.support ∧ a.2 ∈ q.support
⊢ ∀ a_1 ∈ a.1.support ∪ a.2.support, 0 = 0

case neg.e_a.h_add
R : Type ?u.198757
ι : Type u_2
inst✝² : CommSemiring R
S : Type u_1
inst✝¹ : CommRing S
inst✝ : IsDomain S
i : ι
p q : MvPolynomial ι S
hp : ¬p = 0
hq : ¬q = 0
a : (ι →₀ ℕ) × (ι →₀ ℕ)
ha : a.1 ∈ p.support ∧ a.2 ∈ q.support
⊢ ∀ a_1 ∈ a.1.support ∪ a.2.support, ∀ (b₁ b₂ : ℕ), b₁ + b₂ = b₁ + b₂
case neg.e_a.h
R : Type ?u.198757
ι : Type u_2
inst✝² : CommSemiring R
S : Type u_1
inst✝¹ : CommRing S
inst✝ : IsDomain S
i : ι
p q : MvPolynomial ι S
hp : ¬p = 0
hq : ¬q = 0
a : (ι →₀ ℕ) × (ι →₀ ℕ)
ha : a.1 ∈ p.support ∧ a.2 ∈ q.support
j : ι
this : ∀ {f s p q fs ss : ℕ}, fs ≤ p → ss ≤ q → f + s + (p + q - (fs + ss)) = f + (p - fs) + (s + (q - ss))
⊢ a.1 j + a.2 j +
      ((Finsupp.single i p.totalDegree) j + (Finsupp.single i q.totalDegree) j -
        ((Finsupp.single i (a.1.sum fun x m => m)) j + (Finsupp.single i (a.2.sum fun x m => m)) j)) =
    a.1 j + ((Finsupp.single i p.totalDegree) j - (Finsupp.single i (a.1.sum fun x m => m)) j) +
      (a.2 j + ((Finsupp.single i q.totalDegree) j - (Finsupp.single i (a.2.sum fun x m => m)) j))

case neg.e_a.h_zero
R : Type ?u.198757
ι : Type u_2
inst✝² : CommSemiring R
S : Type u_1
inst✝¹ : CommRing S
inst✝ : IsDomain S
i : ι
p q : MvPolynomial ι S
hp : ¬p = 0
hq : ¬q = 0
a : (ι →₀ ℕ) × (ι →₀ ℕ)
ha : a.1 ∈ p.support ∧ a.2 ∈ q.support
⊢ ∀ a_1 ∈ a.1.support ∪ a.2.support, 0 = 0

case neg.e_a.h_add
R : Type ?u.198757
ι : Type u_2
inst✝² : CommSemiring R
S : Type u_1
inst✝¹ : CommRing S
inst✝ : IsDomain S
i : ι
p q : MvPolynomial ι S
hp : ¬p = 0
hq : ¬q = 0
a : (ι →₀ ℕ) × (ι →₀ ℕ)
ha : a.1 ∈ p.support ∧ a.2 ∈ q.support
⊢ ∀ a_1 ∈ a.1.support ∪ a.2.support, ∀ (b₁ b₂ : ℕ), b₁ + b₂ = b₁ + b₂