The traditional model of sequential decision making, for instance, in extensive form games, is a tree. Most texts define a tree as a connected directed graph without loops and a distinguished node, called the root. But an abstract graph is not a domain for decision theory. Decision theory...

We correct a misspecified property in "Trees and Extensive Forms'', Journal of Economic Theory 143 (2008), 216-250. As a consequence a few proofs need to be adjusted, and a few statements need to be adapted. Two minor results, which are not needed for the proofs of the main results, do not hold...

This paper provides a self-contained definition and a characterization of the class of extensive-form games that are adequate for applications, but still do not employ any finiteness assumptions. In spite of its simplicity, the resulting definition is more general than the classical ones....