> From what I understand of the code, you can send fibers to other fibers with the "<<" operator.

You can pass any data between fibers using "receive" and "<<", including fiber refs.

> In my original code sample, my code refers to the children tasks. In your code sample, the parent refers to the children tasks. This seems to be a property of structured concurrency.

In general, yes, but in Polyphony at least you can easily walk the fiber tree using "Fiber#parent" and "Fiber#children".