Section 21.4 - Inverse-Ackermann amortization (legacy compatibility path)
Third-edition-numbered compatibility path for the inverse-Ackermann
amortization. The canonical fourth-edition source is
CLRSLean.FourthEdition.Chapter_19.Section_19_4_Analysis.InverseAckermann;
this module forwards to it so legacy imports keep working during the
compatibility period (see docs/migrations/clrs4.md).