Abstract
Let \mathscr{D}w' be the space of Beurling's generalized distributions on Rn and \mathscr{E}w' the spaces of generalized distributions which has compact support. We show that, for S ∈ \mathscr{E}w', S * \mathscr{D}w'=\mathscr{D}w' is equivalent to the following: Every generalized distribution u ∈ \mathscr{E}w' with S * u ∈ \mathscr{D}w is in \mathscr{D}w.