They mean the same thing. A coroutine is a function, so it doesn't matter if you group "a coroutine" with "a function" or not.

@jwakely So, you suppose that, if the sentence is parsed as the second one it would be a duplicate expound about the function, thus, only the first one is a reasonable way to parse the sentence?

I think it doesn't matter which way you parse it, it means the same thing.

I think it doesn't matter which way you parse it, it means the same thing.

Uh, Do you think

flowing off the end of a function that is neither main nor a coroutine results in UB

has the same meaning with

flowing off the end of a function that is not main, or flowing off the end of a coroutine, results in UB

? The latter obviously conflicts with [dcl.fct.def.coroutine] p11

The coroutine state is destroyed when control flows off the end of the coroutine

Doh, I implicitly negated the coroutine part, sorry. I need to learn to read.

I think your rephrasing as "a function that is neither main nor a coroutine" would be an improvement.