Question

If the strings of a language L can be effectively enumerated in
lexicographic (i.e. alphabetic) order, which of the following statements
is true?
(A) L is necessarily finite
(B) L is regular but not necessarily finite
(C) L is context free but not necessarily regular
(D) L is recursive but not necessarily context free

Answer 1

Answer on Question #37960 – Math - Other

Since $L$ can be effectively enumerated so $L$ has to be regular, but is doesn't mean that the decisions are finite.

Answer: (B) $L$ is regular but not necessarily finite.