“…One needs then to bypass such a difficulty; see, for example, [12] for the construction of toric varieties associated to non rational fans. In this connection, we mention some references that might inspire ideas for deciding such conjectures about exponential sums [38,43,41,45,46,49,50,51,54,56]. Unfortunately, most of them do not really take into account the arithmetic constraints, and are more in the spirit of C. Moreno's papers [47,48].…”