Prove that 0m 1n m n 1 and m is divisible by n is not contex
     Prove that {0^m 1n |m, n  1 and m is divisible by n} is not context-free. 
  
  Solution
We prove using parkhs theorem..
 If language is contect free grammar, then it need to be satisfy condition w = uvxyz
* |vxy| <= p
 * |vy| > 0
 For all i>=0 we have wv^i xy^i z belongs to L
But in our situtation, we cannot generate sequence as above rules,
 Since as per condition m,n divisible by n following strings are can generate which are regular
if n = 2
 01
 0011
 0000011
 The strings generated are irregular and we got contradiction as per our assumption.
 So given {0^m1^n | m,n >=1 and m is divisible by n} is non-context free.

