Language of Strings Over {a, b} Where Every a is Followed by b
- Base Case: The empty string ε and the string b are in the language LLL.
- Recursive Step:
- If xxx is in LLL, then b⋅xb \cdot xb⋅x and ab⋅xab \cdot xab⋅x are in LLL.
- Closure: A string is in LLL if and only if it can be derived from the base case using a finite number of applications of the recursive step.