No

Yes , with input alphabet  as ∑*

Yes

Set of all strings with equal number of a’s and b’s

Set of strings where a is followed by b

Set of palindromes over {a, b}

Set of all strings over {a, b}

Recursive

Regular

A regular expression generating both lists

A context-free grammar creating both string sets

A finite automaton accepting matching strings

A sequence of indices producing equal strings from two lists

None of the above 

It always halts

It has finite tape

It cannot be simulated by a computer

Testing if a DFA accepts a string

Testing if a regular expression equals a DFA

Testing if a DFA is empty

Testing if a CFG is ambiguous

Regular Language Machine

Linear Bounded Automaton (LBA)

L={ a, b }*

L={ W | W contains sb }

L= { aⁿbⁿ | n ≥ 0 }

L={ w | w contains bs }

Concatenation

Union

Intersection

Keen closure