“…Set-indexed processes constitute a natural generalization of multiparameter stochastic processes and their local regularity have been considered in the Gaussian case since the early work of Dudley [14] (see also [1,3,8]). Extending the literature on random fields, several different subjects have been recently investigated, including set-indexed martingales [21], setindexed Markov [20,5,6] and Lévy processes [1,7,19], and set-indexed fractional Brownian motion [17,18]. Although the set-indexed formalism appears to be more abstract, it usually offers a simpler and more condensed way to express technical concepts of multiparameter processes.…”