Well, maybe I did imagine a world in which the Morning Star exists and the Evening Star doesn't exist, but maybe imagining doesn't mean it's possible.

或许我想象这一个,晨星存在,但昏星不存在的世界,但也许想象并不表示可能

耶鲁公开课 - 死亡课程节选

So, in particular, if you're person 1 and then "s-i" would be "s2, s3, s4" up to "sn" but it wouldn't include "s1."

具体来说如果你是参与人1那么,si-可能表示s2,s3,s4,直到sn,但是不包括s1

耶鲁公开课 - 博弈论课程节选