2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/110063In this paper a stochastic equation on compact groups in discrete negative time is studied. This is closely related to Tsirelson's stochastic differential equation, of which any solution is non-strong. How the group action reflects on the set of solutions is investigated. It is applied to generalize Yor's result and give a necessary and sufficient condition for existence of a strong solution and for uniqueness in law.23pagesProbability60H10; 60B15text