I want to see @f1(what will happen) if we put the
font change commands @f1(on a set of lines).  If I understand
things (correctly), the @f1(third) line causes problems. (No?).
Is this really the case, or is it (maybe) just something else?

Let's test having two on a line @f1(here) and @f1(there) as
well as one that begins on one line and ends @f1(somewhere 
on another line).  What if @f1(it is here) on the line?
Another @f1(one).