Why is the Exodus from Egypt not mentioned in prayer or in Havdalah?

This source-based Torah study examines the question: Why is the Exodus from Egypt not mentioned in prayer or in Havdalah? The canonical Hebrew article develops the issue through the weekly Torah portion and the sources cited there. This localized discovery layer preserves the question and the source identity; it does not add any new halakhic, medical, legal, scientific, historical, theological, or empirical ruling or claim beyond the canonical Hebrew source.