EF-Games, Characterizations and Lindström Theorems
Cheng Liao · 2022
The Ehrenfeucht–Fraïsse game for a logic usually provides an intuitive characterization of its expressive power while in abstract model theory, logics are compared by their expressive powers. In this presentation , I will expose this connection in details by showing a general Lindström theorem for logics which have certain types of Ehrenfeucht–Fraïsse games. I will first prove a general characterization theorem and then move forward to get a Lindström theorem (with more assumptions about the logics we consider). The results generalize and uniform some known results and may be applied to get new Lindström theorems for logics.