I'm not sure that's a solution. The problem is verifying that the three 'n's are equal, not that 'a', 'b', and 'c' are equal. Solving this cannot be done in a c

I'm not sure that's a solution. The problem is verifying that the three 'n's are equal, not that 'a', 'b', and 'c' are equal. Solving this cannot be done in a context free grammar [0]. [0]: https://cs.stackexchange.com/questions/33153/is-an-bn-cn-context-free https://cs.stackexchange.com/questions/33153/is-an-bn-cn-con...