Description
2.
– ๐ด & ๐ต are both regular languages, so according to the theorem that regular languages are closed under complement proves that ๐ดฬ
& ๐ตฬ
are also regular languages.
– Under the theorem that regular languages are closed under intersection and union, we know that equations like ๐ด โฉ ๐ต = ฬ
๐ดฬ
ฬ
ฬ
โชฬ
ฬ
ฬ
๐ตฬ
ฬ
are regular.
– ๐ด โ ๐ต can be written as ๐ด โฉ ๐ตฬ
– As said earlier, under the theorem that regular languages are closed under complement ๐ด & ๐ตฬ
are regular.
– Finally since ๐ด โฉ ๐ตฬ
is a regular language, ๐ด โ ๐ต is also a regular language.



