Toward mixed multiplicities and joint reductions

In the direction towards the question when mixed multiplicities are equal to the Hilbert-Samuel multiplicity of joint reductions, this paper not only generalizes [28, Theorem 3.1] that covers the Rees's theorem [13, Theorem 2.4], but also removes the hypothesis that joint reductions are systems of parameters in [28, Theorem 3.1]. The results of the paper seem to make the problem of expressing mixed multiplicities into the Hilbert-Samuel multiplicity of joint reductions become closer.