Expression can be simplified on list

[Rustom Mody]

On Wednesday, September 14, 2016 at 5:35:53 PM UTC+5:30, Jussi Piitulainen wrote:
> Mathematical discussions tend to acknowledge only alternation (union),
> concatenation and iteration (Kleene star) as operations, unless they
> specifically focus on some other operations that can, in principle, be
> expressed in terms of those three. There are many such.
> 
> Without further regex operations it makes sense to include a special
> regular expression that matches nothing.  Otherwise a very simple NFA
> (DFA) has no corresponding regex, which can be considered awkward.

Not sure if I parse you correct — Assuming “a very simple DFA” you mean 
“The DFA with only one state, no final state?”
If yes then yes thats the nub of the matter

More later…

[Will switch from being a CS-teacher to net-disconnected music teacher for few days :-) ]