It would be nice to have examples which `extend to the other range`. Eg. the first example shows how to not extend, the second shows how to extend. Or `range` examples shows how to not extend left/right, and the `multirange` examples shows how to extend to the left/right.
The use of the word "how" here might just be a translation thing but to be sure this isn't about an action, it is strictly about whether the lower bound of the left argument is greater or less than the lower bound of the right argument.
I'll agree that all of this takes some thinking to understand but I don't know that simply adding examples that return false instead of true is a big gain.
Maybe reword it, removing the "not"?
Thus:
Does the first range not extend to the left of the second?
Becomes:
Is the lower bound of the first range larger than or equal to the lower bound of the second range?
