Some notational bugs in the bulleted list in "Definition part (a): "part of the world" that come up in trying to communicate about this with someone:
In the first bullet, W∈W should probably be w∈W both for consistency with later bullets, and so that it does not seem like TW is subscript-indexed over some W∈W. (I'm inferring that subscript W is just part of the name of TW.)
In bullet 6 about Fut(w), the sentence should end with w∈W, not w∈W.
The last three bullet points should maybe use wt instead of Wt, or else maybe all the lowercase ws should be made capital.
Some notational bugs in the bulleted list in "Definition part (a): "part of the world" that come up in trying to communicate about this with someone:
In the first bullet, W∈W should probably be w∈W both for consistency with later bullets, and so that it does not seem like TW is subscript-indexed over some W∈W. (I'm inferring that subscript W is just part of the name of TW.)
In bullet 6 about Fut(w), the sentence should end with w∈W, not w∈W.
The last three bullet points should maybe use wt instead of Wt, or else maybe all the lowercase ws should be made capital.