Andrei Morozov: "On F-parameterizable models" ABSTRACT: I will be speaking on a general method to answer questions like "Is a group G an elementary subgroup of the group $Sym(\omega)$"? "Is a group G an elementary subgroup of the group $Aut$"? and many other questions like this, not only for groups. The method I suggest shows, for instance, that the groups of all computable, arithmetical, hyperarithmetical permutations, $\Pi_n^1$-permutations, $\Sigma_n^1$-permutations ($n\in\omega$) fail to be elementary subgroups in $Sym(\omega)$. I also prove some general results on the structure of elementary submodels.