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Special Cases: Examples

Some special cases as an example:

Answer:

This language looks like infinite palindrome as previous all examples Important Exercise and Solutions and because of it is infinite palindrome it NCFL.

But this language is not NCFL. 

So, ‘x’ is not a special symbol, it represents strings just like ‘ω’.

So, we can derive a regular expression for this language.

As we know if we write a regular expression for a language then it is definitely a regular language.

Still, we have confusion that –

Is it giving a regular expression?

Let take an example 

Let,

So, we can visualize like that

And 

So, we can form a regular expression from this language.

Another two similar examples as above:

This language is the same as above because we put 

then still regular expression will same.

For better understanding see Example 1. 

If we have confusion that -  

Then we write the same Regular Expression for it. 

Let take an example 

Let, 

So, we can visualize like that

And  

So, we can form a regular expression from this language, it is a Regular Language.