FOR FREE YEAR SOLVED

Example: 

 

L = ambn, m > n

 

Consider a language, 

 

 

Design the corresponding Push Down Automata (PDA).

 

You should know:

 

Before seeing the solution please follow the previous chapter to clear the concept (How to identify language),   Language Identify: Example 9Language Identify: Examples 12

 

Solution:

 

This given language is a Deterministic Context Free Language (DCFL) because it has one infinite comparison and push and pop are cleared in that case. (For more details see the above links)

 

As per the given language number of ‘a’ is greater than of the number of ’b’ in all strings belongs to this given language.

 

So, in that case, we push ‘a’ into the stack whenever we will get ‘a’ as input and we pop ‘a’ from the stack whenever we will get ‘b’ as input.  After scanning all inputs if the input tape will be empty but the the stack still has alphabet ‘a’ then we can say string is accepted otherwise rejected.

 

Example: 

 

 

 

Corresponding DPDA: