Which ONE of the following languages is accepted by a deterministic pushdown automaton?
Let $G_1, G_2$ be Context Free Grammars (CFGs) and $R$ be a regular expression. For a grammar $G$, let $L(G)$ denote the language generated by $G$. Which ONE among the following questions is decidable?
Consider the two lists List-I and List-II given below:
| List - I | List - II | ||
|---|---|---|---|
| (i) | Context free languages | (a) | Closed under union |
| (ii) | Recursive languages | (b) | Not closed under complementation |
| (iii) | Regular languages | (c) | Closed under intersection |
For matching of items in List-I with those in List-II, which of the following option(s) is/ are CORRECT?
Consider the following context-free grammar $G$, where $S, A$, and $B$ are the variables (nonterminals), $a$ and $b$ are the terminal symbols, $S$ is the start variable, and the rules of $G$ are described as:
$$\begin{aligned} & S \rightarrow a a B \mid A b b \\ & A \rightarrow a \mid a A \\ & B \rightarrow b \mid b B \end{aligned}$$
Which ONE of the languages $L(G)$ is accepted by $G$ ?