If someone accepted Shabbat early, can that early acceptance be annulled?

This source-based Torah study examines: If someone accepted Shabbat early, can that early acceptance be annulled? It follows the canonical Hebrew discussion and the classical sources cited there, preserving the distinctions and review status of the original. This localized layer is for study and discovery only; it is not practical halakhic, legal, military, medical, safety or pastoral advice.