English
For any f ∈ R[X], reverse f has natDegree equal to natDegree(f) minus natTrailingDegree(f): reverse(f).natDegree = f.natDegree − f.natTrailingDegree.
Русский
Для любого f ∈ R[X] natDegree(reverse f) = natDegree(f) − natTrailingDegree(f).
LaTeX
$$$\operatorname{natDegree}(\operatorname{reverse}(f)) = \operatorname{natDegree}(f) - \operatorname{natTrailingDegree}(f).$$$
Lean4
theorem reverse_natDegree (f : R[X]) : f.reverse.natDegree = f.natDegree - f.natTrailingDegree := by
rw [f.natDegree_eq_reverse_natDegree_add_natTrailingDegree, add_tsub_cancel_right]