It is the allocation of distribution functions of joint probabilities, of each family of finite random variables. In fact, the probabilistic characterization of a stochastic process Y(t) is obtained by assigning the joint distribution of each finite family of random variables. So given the random variables and the time index:
the temporal law is assigned with:
AA.VV., Matematica Finanziaria, Monduzzi Editore, 1998.
Grinstead M. C., Snell J. L., Introduction to Probability, American Mathematical Society, 1997.
Editor: Giuliano DI TOMMASO