We study the expressive power of open formulas of dependence logic introduced in Väänänen [Dependence logic (Vol. 70 of London Mathematical Society Student Texts), 2007]. In particular, we answer a question raised by Wilfrid Hodges: how to characterize the sets of teams definable by means of identity only in dependence logic, or equivalently in independence… (More)
We introduce a modal language which involves the concept of dependence. We give two game-theoretic definitions for the semantics of the language, and one inductive, and prove the equivalence of all three.
The concept of a generalized quantiier of a given similarity type was deened in Lin66]. Our main result says that on nite structures diierent similarity types give rise to diierent classes of generalized quantiiers. More exactly, for every similarity type t there is a generalized quantiier of type t which is not deenable in the extension of rst order logic… (More)
The semantics of the independence friendly logic of Hintikka and Sandu is usually deened via a game of imperfect information. We give a new deenition in terms of a game of perfect information. We also give an Ehrenfeucht-Fra ss e game adequate for this logic. We consider a logic IF which is the closure of atomic and negated atomic formulas of rst order… (More)