Effect of different sublist execution?

[Sebastian Gniazdowski <sgniazdowski@xxxxxxxxx>]

Doc say:

If a sublist is terminated by a `&',
`&|', or `&!', the shell executes the last pipeline in it in the  back‐
ground,  and  does  not wait for it to finish (note the difference from
other shells which execute the whole sublist  in  the  background).

I wonder about presenting this via some real effect. How to show that
only the last pipeline is running in background (like the doc say)
when sublist/pipeline is ended via &? I'm looking for a snippet that
will behave differently for the two cases: sublist &-ended and ;-ended
.

-- 
Best regards,
Sebastian Gniazdowski