I have been looking around for a good source to answer the following question. Have read a few different sources but have not found the answer I was looking for.
The question is:
Give an example of an infinite set of:
a. Regular languages whose union is a regular language
b. Regular languages whose union is a non-regular language
c. Non-regular languages whose union is a regular language
d. Non-regular languages whose union is a non-regular language
I've used this post to answer part b, and I understand the method behind it (at least I think I do).
What is the right way to approach this question?
Wouldn't an infinite set of anything constitute a non-regular language, by definition?