(b) Consider the following binary relation $\subseteq$, defined over the set of all
NFAs by setting, for any NFAs $M_1$, $M_2$:
$M_1 \subseteq M_2$ iff $L(M_1) \subseteq L(M_2)$
That is, $M_1 \subseteq M_2$ iff the language recognised by $M_1$ is a subset of the
language recognised by $M_2$. Is $\subseteq$ an equivalence relation? Justify your
answer.
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(c) Let A be the set of all strings over the alphabet {0, 1} that do not end
with more than two consecutive 0s. Examples of strings in A would
be: $\epsilon$, 1, 100, 0110. Examples of strings not in A would be: 1000,
0011000000, 11101000.
(i) Is the following statement true or false?:
There is a regular expression representing A
You must fully justify your answer. Any definitions, theorems or
propositions from the lecture notes that you use must be clearly
stated in full.
[5]
(ii) Is it true that 11101000 $\in$ A*? Justify your answer.
[2]