2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/163430Inspired by Lehner's results on exchangeability systems we define `weak conditional freeness' and `conditional freeness' for stationary processes in an operator algebraic framework of noncommutative probability. We show that these two properties are equivalent and thus the process embeds into a von Neumann algebraic amalgamated free product over the fixed point algebra of the stationary process.9 pagesOperator Algebras46L54; 46L53; 60G09text