關注學習中,很好的資料

IN the extensive form game, involving imperfect  information, every node is in one and only one information set.
Thus, some times an information set contains one node, and sometime contains many nodes.
TO understand what is an information set, there are basically:
A set of nodes that a player assigned to move on, but cannot distinguish ameng them.
Less, concretely, it means that, The player  who is assigned to move on the information set, he knows that he is in the information set, but he dont know exaclty which node.
Its like a simutaneously move game.

THere are some restrictions:

I suggest you to look at Yale Game theory open course, its very helpful.

那图中局中人1行动的信息集是不是书上画错了？

没有啊。其实信息集，比较难的地方叫做PERFECT RECALL。
这里应该没有出现这个情况

我知道了，图中应该是不完善记忆的情况