For regular lang - if u r able to write a regular expression or DFA is possible
For DCFL- No. Of push and pop should be clear
ex-a^4b^4
Here for a we will do push and for b will do pop . So push and pop are clear here
but when double comparison with or on different variable then it wont be dont by DPDA.
Ex. (a^n b^m c^p)and either n should be greater than m OR m should be less than p
Here Dpda will not work but Npda will do it so it is CFL BUT NOT DCFL.
CSL-
(a^n b^n c^n ) and n is greater then eqal to 0
now 3 comparison so pda has 1 stack and it has 2 comparision . For making all 3 equal 2 stack is needed.
Bcz for a do push,for b do pop and if we get stack empty that means eqal no of a and b but for making c equal we have nothing in stack .
