erw [homogenization, Finsupp.mapDomain_single, single_eq_monomial, totalDegree_monomial _ hr,
  tsub_self]
case neg
R : Type u_2
ι : Type u_1
inst✝ : CommSemiring R
i : ι
s : ι →₀ ℕ
r : R
hr : ¬r = 0
⊢ homogenization i ((monomial s) r) = (monomial s) r
case neg
R : Type u_2
ι : Type u_1
inst✝ : CommSemiring R
i : ι
s : ι →₀ ℕ
r : R
hr : ¬r = 0
⊢ (monomial (s + Finsupp.single i 0)) r = (monomial s) r