Explicit summation of the constituent WKB series and new approximate wave functions.
In this article we introduce the convergence of extended realvalued double sequences [16], [17]. It is similar to our previous articles [15], [10]. In addition, we also prove Fatou’s lemma and the monotone convergence theorem for double sequences.
We show that the ideal of nowhere dense subsets of rationals cannot be extended to an analytic P-ideal, ideal nor maximal P-ideal. We also consider a problem of extendability to a non-meager P-ideals (in particular, to maximal P-ideals).