原书为「可列可加性」 https://github.com/re-book/ptmst/blob/83eb4f5fface45e8c473ae1e79b603228864aa38/chapter1.tex#L2113 原书第一项为 $P(\emptyset)$ https://github.com/re-book/ptmst/blob/83eb4f5fface45e8c473ae1e79b603228864aa38/chapter1.tex#L2119 左边一项应为 $A$ https://github.com/re-book/ptmst/blob/83eb4f5fface45e8c473ae1e79b603228864aa38/chapter1.tex#L2254
原书为「可列可加性」
ptmst/chapter1.tex
Line 2113 in 83eb4f5
原书第一项为
ptmst/chapter1.tex
Line 2119 in 83eb4f5
左边一项应为
ptmst/chapter1.tex
Line 2254 in 83eb4f5