Wait... What?!
1 <= local_ChapterNumber AND local_ChapterNumber <= 100
I mean, it's obvious when you see it. But there's no mention of AND (or OR) on the Calculations page and it isn't listed in the Operators table, a search of the Wiki for "boolean" throws up nothing relevant, and I even lamented not being able to use such logic directly a few months ago (and I'm sure I tried AND as well as the bitwise & and the post's desperation &&).
I am going to be so annoyed with myself if I've missed something obvious!