Question

Among the following languages, choose one that is not regular.

a) The set of binary strings of even length.
b) The set of binary strings having at least 3 zeroes and at least 3 ones.
c) {ambn: m ≥ n}.
d) The set of binary strings not containing the substring 1011 anywhere.

Answer 1

The language that is not regular is {ambn: m ≥ n}.

Step-by-step explanation:

Among the given options, the language that is not regular is option c) {ambn: m ≥ n}. This language represents strings with a number of 'a's that is greater than or equal to the number of 'b's. The language is not regular because it requires unbounded memory to keep track of the number of 'a's and 'b's and check if the condition is satisfied. Regular languages can be recognized by finite automata, which have limited memory.