You do not have permission to edit this page, for the following reason:

The action you have requested is limited to users in one of the groups: Users, Administrators.


You can view and copy the source of this page.

Return to Grammar: Decidable and Undecidable Problems.

Closure properties of language families
Operation Regular DCFL CFL CSL Recursive RE
Union Yes No Yes Yes Yes Yes
Intersection Yes No No Yes Yes Yes
Complement Yes Yes No Yes Yes No
Concatenation Yes No Yes Yes Yes Yes
Kleene star Yes No Yes Yes Yes Yes
Homomorphism Yes No Yes No No Yes
<math>\epsilon</math>-free Homomorphism Yes No Yes Yes Yes Yes
Substitution (<math>\epsilon</math>-free) Yes No Yes Yes No Yes
Inverse Homomorphism Yes Yes Yes Yes Yes Yes
Reverse Yes No Yes Yes Yes Yes