At 12:32 07/05/2004 +0100, Peter McBurney <p.j.mcburney@csc.liv.ac.uk> wrote:
One difference is that von Neumann/Nash games typically assume a payoff (a reward or loss) to participants upon termination of the game, whereas the abstract games discussed in game semantics usually do not assume this.
That is a nice point. In consequence, so far as I know, no one is interested in `mixed strategies' for games in set theory or semantics. There is no sense to the `average/expected payoff' for a randomized strategy as there is no payoff. Mixed strategies are the focus of most economic and such uses of game theory. The usual question is how to find optimal mixed strategies when there is no winning one. The usual question for games in set theory or semantics is just whether one player has a winning strategy. That is the only question in the uses I know of.