Univariate monomials #
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Preparatory lemmas for degree_basic.
    
theorem
polynomial.monomial_one_eq_iff
    {R : Type u}
    [semiring R]
    [nontrivial R]
    {i j : ℕ} :
⇑(polynomial.monomial i) 1 = ⇑(polynomial.monomial j) 1 ↔ i = j
@[protected, instance]
    
theorem
polynomial.ring_hom_ext
    {R : Type u}
    [semiring R]
    {S : Type u_1}
    [semiring S]
    {f g : polynomial R →+* S}
    (h₁ : ∀ (a : R), ⇑f (⇑polynomial.C a) = ⇑g (⇑polynomial.C a))
    (h₂ : ⇑f polynomial.X = ⇑g polynomial.X) :
f = g
@[ext]
    
theorem
polynomial.ring_hom_ext'
    {R : Type u}
    [semiring R]
    {S : Type u_1}
    [semiring S]
    {f g : polynomial R →+* S}
    (h₁ : f.comp polynomial.C = g.comp polynomial.C)
    (h₂ : ⇑f polynomial.X = ⇑g polynomial.X) :
f = g