“…Taking into account the aforementioned motivations, the aim of this paper is twofold. First, we intend to present a complete and detailed exposition of the foundations of the independence rule (That can be considered a tool for variable forgetting), whose basic ideas were published in [10], since no detailed exposition has been published until now. In fact, we generalize the cited paper by stating the results for any operator that induces a conservative retraction, leading as consequence that our case, the independence rule, is useful to compute the retractions.…”