In order to analyze the singularities of a power series P (t) on the boundary of its convergent disc, we introduced the space Ω(P ) of opposite power series in the opposite variable s=1/t, where P (t) was, mainly, the growth function (Poincaré series) for a finitely generated group or a monoid [S1]. In the present paper, forgetting about that geometric or combinatorial background, we study the ...
