Key points are not available for this paper at this time.
We also denote by 5.5.f(x) the support of a microfunction f(x).A hyperfunction f(x) is real analytic if and only if 5.5.f(x) = (f >.* Different A's give isomorphic systems if and only if the difference is an integer.If we use micro-differential operators of fractional order any A gives the same system.
Miwa et al. (Fri,) studied this question.