From pure to approximate logic

Helena Rasiowa could be described as an atypical mathematician since, being a pure theoretician in the first part of her scientific life (1945-70), she changed course swiftly, around 1970, by applying her own abstract methods to practically-motivated theoretical problems arising in computer science (the analysis of computer programs) and artificial intelligence (the logic of approximations). The reasons behind such a shift of emphasis and the invariant motivations she kept along her whole life are explored in this homage-rendering contribution.