English
The constant term is preserved by renaming: constantCoeff (rename f φ) = constantCoeff φ.
Русский
Постоянная часть сохраняется при переименовании: constantCoeff (rename f φ) = constantCoeff φ.
LaTeX
$$$ constantCoeff (rename f \phi) = constantCoeff \phi $$$
Lean4
@[simp]
theorem constantCoeff_rename {τ : Type*} (f : σ → τ) (φ : MvPolynomial σ R) :
constantCoeff (rename f φ) = constantCoeff φ :=
by
apply φ.induction_on
· intro a
simp only [constantCoeff_C, rename_C]
· intro p q hp hq
simp only [hp, hq, map_add]
· intro p n hp
simp only [hp, rename_X, constantCoeff_X, map_mul]