In this article, we construct a mapping : D[0, [infinity])xD[0,[infinity])-->D[0,[infinity]) such that if (Xt) is a semimartingale on a probability space ([Omega], , P) with respect to a filtration (t) and if (ft) is an r.c.l.l. (t) adapted process, then This is of significance when using stochastic integrals in statistical inference problems. Similar results on solutions to SDEs are also given.