Section 22.3 - Intervals and timestamps (legacy compatibility path)
Third-edition-numbered compatibility path for the interval/timestamp theory. The canonical
fourth-edition source is
CLRSLean.FourthEdition.Chapter_20.Section_20_3_DFS.S2_Intervals;
this module forwards to it so legacy imports keep working during the
compatibility period (see docs/migrations/clrs4.md).