Tagged Questions
1
vote
2answers
80 views
Infinite union of finite unions
Is the following sound reasoning, and if so, why?
Letting $S$ be a language over the alphabet $\Sigma$,
$$
\bigcup_{i=0}^{\infty}\left(\bigcup_{k=0}^{i-1}S^k\right) = \bigcup_{i=0}^{\infty}S^i
$$
0
votes
2answers
81 views
Help with regular expression subset proof
Okay, so basically I'm just showing that two ways to express a regular expression are equal, and to do so, I'm showing they're subsets of each other.
The expression is:
$(A^*B^*)^* \subset ...
