Please meddle, Bilbo. I find it enlightening. A thread like this is much more interesting than just reading docs. So far I've learned:

• Sequence Numbers: in the docs, but good refresher on how to get to them. Change loop to mid-decision test in scalar context via next/last.
• Ending Number: will the E0 thing break in Perl 6, when it becomes 6 is true instead? Will the autotranslator handle this subtle point? Since the E0 is harmless, they should keep that for legacy, even if they add the property as well.
• Your Sub Idiom: as noted in my node.
• Put Real Code in Test: having a block with scratch work that returns the real result is something to keep in mind. Can't do that in C++.
• Precidence
• Aliasing

—John