The nodes of an extensive-form game are commonly specified as sequences of actions. Rubinstein calls such nodes histories. We find that this sequential notation is superfluous in the sense that nodes can also be specified as sets of actions. The only cost of doing so is to rule out games with...

The nodes of an extensive-form game are commonly specified as sequences of actions. Rubinstein calls such nodes histories. We find that this sequential notation is superfl uous in the sense that nodes can also be specified as sets of actions. The only cost of doing so is to rule out games with...