Finite Atomata

Question

Complement of non regular language is regular or not?

Answer 1

The family of regular languages is closed under complementation.

The family of Deterministic context-free languages is closed under complementation.
The family of Non-deterministic context-free languages is not closed under complementation.

The family of Recursive languages is closed under complementation.
The family of Recursive Enumerable Sets is not closed under complementation.

Check this: http://gatecse.in/closure-property-of-language-families/