Extensive Form Reasoning in Normal Form Games
发现不同扩展形式博弈即使有相同简化正规形式，其信息集和子博弈也可能不同。作者提出战略独立性概念，用正规形式定义信息集和子博弈，并证明与扩展形式结构的紧密关系，进而用正规形式实现子博弈完美均衡、序贯均衡和前向归纳等解概念。
Different extensive form games with the same reduced normal form can have different information sets and subgames. This generates a tension between a belief in the strategic relevance of information sets and subgames and a belief in the sufficiency of the reduced normal form. We identify a property of extensive form information sets and subgames which we term strategic independence. Strategic independence is captured by the reduced normal form, and can be used to define normal form information sets and subgames. We prove a close relationship between these normal form structures and their extensive form namesakes. Using these structures, we are able to motivate and implement solution concepts corresponding to subgame perfection, sequential equilibrium, and forward induction entirely in the reduced normal form, and show close relations between their implications in the normal and extensive form.