Viggo Stoltenberg-Hansen is a Professor at Uppsala Universitet, Sweden and researches computability theory, constructive mathematics, type theory, domain theory, categorical logic and model theory.
Jouko Väänänen is a professor at the University of Helsinki, Finland where he researches foundations of mathematics, logic in computer science, semantics of natural language, games, generalized quantifiers, infinitary languages, abstract logic, model theory and set theory.