Reexamination of Strategy Equivalence in Extensive Form Games
We show that two strategies are Kuhn equivalent if and only if they induce the same measure over terminal nodes against some profile of completely mixed behaviour strategies of the other players. This result allows us to embed the equivalence classes of strategies in the measures over terminal nodes for various strategy concepts. This, in turn, allows a very clean statement of the relation between the various sets of strategies in games with perfect recall, linear games, and nonlinear games. It also proves useful in defining and analysing solution concepts in games without perfect recall, and, in particular, in nonlinear games.