If \( L_i \) is the set of languages of type \( i \) for \( i = 0, 1, 2 \) or 3. Then, as per Chomsky hierarchy, arrange the given set of four languages in order from subset to superset, from left to right.
(A) \( L_3 \)
(B) \( L_2 \)
(C) \( L_1 \)
(D) \( L_0 \)
Choose the correct answer from the options given below:
Step 1: Understanding the Chomsky Hierarchy.
In the Chomsky hierarchy, languages are classified into four types based on their complexity: - Type 0: Recursively enumerable languages
- Type 1: Context-sensitive languages
- Type 2: Context-free languages
- Type 3: Regular languages
The hierarchy is ordered as follows, with each type being a subset of the next: \[ L_3 \subseteq L_2 \subseteq L_1 \subseteq L_0 \]
Step 2: Applying the Order.
From the Chomsky hierarchy, we know that regular languages (\( L_3 \)) are the simplest and are a subset of context-free languages (\( L_2 \)), which in turn are a subset of context-sensitive languages (\( L_1 \)), and finally, recursively enumerable languages (\( L_0 \)) are the most general.
Step 3: Conclusion.
Therefore, the correct order from subset to superset is \( L_3 \), \( L_2 \), \( L_1 \), and \( L_0 \), which corresponds to option (1) A, B, C, D.
Find the least upper bound and greatest lower bound of \( S = \{X, Y, Z\} \) if they exist, of the poset whose Hasse diagram is shown below:
Suppose \( D_1 = (S_1, \Sigma, q_1, F_1, \delta_1) \) and \( D_2 = (S_2, \Sigma, q_2, F_2, \delta_2) \) are finite automata accepting languages \( L_1 \) and \( L_2 \), respectively. Then, which of the following languages will also be accepted by the finite automata:
(A) \( L_1 \cup L_2 \)
(B) \( L_1 \cap L_2 \)
(C) \( L_1 - L_2 \)
(D) \( L_2 - L_1 \)
Choose the correct answer from the options given below: