English
The embedding of a monomial into the power-series ring is exactly the corresponding multivariate power-series monomial.
Русский
Встраивание мономиала в кольцо степенных рядов даёт тот же самый степенной ряд-мономиал.
LaTeX
$$$\\uparrow(\\mathrm{monomial}\\, n\\, a) = \\mathrm{MvPowerSeries.monomial}\\, n\\ a$$$
Lean4
@[simp, norm_cast]
theorem coe_monomial (n : σ →₀ ℕ) (a : R) : (monomial n a : MvPowerSeries σ R) = MvPowerSeries.monomial n a :=
MvPowerSeries.ext fun m => by
classical
rw [coeff_coe, coeff_monomial, MvPowerSeries.coeff_monomial]
split_ifs with h₁ h₂ <;>
first
| rfl
| subst m; contradiction