VII: 23, 223-247, LNM 321 (1973) MEYER, Paul-André Sur un problème de filtration (General theory of processes) This is an attempt to present, in the usual language of the seminar, a a simple case from filtering theory (additive white noise in one dimension). The results proved are the Kallianpur-Striebel formula (Ann. Math. Stat., 39, 1968) and a theorem of Clark Keywords: Filtering theory, Innovation Nature: Exposition Retrieve article from Numdam