Elementary numerosity and measures

Abstract

In this paper we introduce the notion of elementary numerosity as a special function dened on all subsets of a given set which takes values in a suitable non-Archimedean field, and satises the same formal properties of finite cardinality. We investigate the general compatibility of this notion with the notion of measure. As an application, we present a model for the probability of infinite sequences of coin tosses, directly obtained from a suitable elementary numerosity.