Explaining NFA in words I have an NFA, and the question I am asked is :
Let  &lt;  &lt; . Now in simple English, express the language of the NFA to explain what type of strings are accepted by it.
In simple English, my answer is
The NFA accepts strings over alphabet {a, b, c} such that the last symbol appears twice.
Which I know is correct, however my problem lies in the question where &quot;a &lt; b &lt; c&quot;. How does this affect my NFA and is my answer still correct? My answer seems really short for 6 marks.
The automaton accepts all non-empty strings in which the last symbol $\sigma$ appears at least twice, and all symbols appearing between its penultimate appearance and its last appearance are smaller than $\sigma$.