English
The dual-to-original embedding preserves nat casting: for any n, (toDual(ofNat n)) = ofNat n in the dual setting.
Русский
Преобразование обратно в исходный порядок сохраняет nat casting: for all n, (toDual(ofNat n)) = ofNat n.
LaTeX
$$$ toDual\big((\mathrm{ofNat}(n) : \alpha^{\mathrm{opp}})\big) = \mathrm{ofNat}(n) $$$
Lean4
@[simp]
theorem ofDual_ofNat [NatCast α] (n : ℕ) [n.AtLeastTwo] : (ofDual (ofNat(n) : αᵒᵈ)) = ofNat(n) :=
rfl