You can easily use regex to verify a regular language. My question is can you use it to verify a context-sensitive language? How powerful is the modern regex in the hierarchy?
How would you go about to create a regex that checks for strings that match a^n b^n c^n?
The following cases should match:
abc
aabbcc
aaabbbccc
The following cases should not match:
abbc
aabbc
aabbbccc